Android开发中滑动分页功能实例详解
作者：guochongcan
这篇文章主要介绍了Android开发中滑动分页功能,结合实例形式详细分析了Android滑动分页功能的具体步骤与相关实现技巧,代码中备有详尽的注释便于理解,需要的朋友可以参考下
本文实例讲述了Android开发中滑动分页功能。分享给大家供大家参考，具体如下：
android UI 往右滑动，滑动到最后一页就自动加载数据并显示
如图：
Java代码：
package cn.anycall.ju;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.Context;
import android.content.Intent;
import android.content.pm.ResolveInfo;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.view.KeyEvent;
import android.view.View;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.GridView;
import android.widget.Toast;
import cn.anycall.ju.ScrollLayout.OnScreenChangeListenerDataLoad;
/**
* GridView分页显示安装的应用程序
*/
public class AllAppList extends Activity {
private ScrollLayout mScrollLayout;
private static final float APP_PAGE_SIZE = 4.0f;
private Context mContext;
private PageControlView pageControl;
public MyHandler myHandler;
public int n=0;
private DataLoading dataLoad;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
mContext = this;
setContentView(R.layout.main);
dataLoad = new DataLoading();
mScrollLayout = (ScrollLayout)findViewById(R.id.ScrollLayoutTest);
myHandler = new MyHandler(this,1);
//起一个线程更新数据
MyThread m = new MyThread();
new Thread(m).start();
}
/**
* gridView 的onItemLick响应事件
*/
public OnItemClickListener listener = new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
// TODO Auto-generated method stub
System.out.println("position="+position);
}
};
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
android.os.Process.killProcess(android.os.Process.myPid());
super.onDestroy();
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
// TODO Auto-generated method stub
if (keyCode == KeyEvent.KEYCODE_BACK) {
finish();
return true;
}
return super.onKeyDown(keyCode, event);
}
// 更新后台数据
class MyThread implements Runnable {
public void run() {
try {
Thread.sleep(1000*3);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
String msglist = "1";
Message msg = new Message();
Bundle b = new Bundle();// 存放数据
b.putString("rmsg", msglist);
msg.setData(b);
AllAppList.this.myHandler.sendMessage(msg); // 向Handler发送消息,更新UI
}
}
class MyHandler extends Handler {
private AllAppList mContext;
public MyHandler(Context conn,int a) {
mContext = (AllAppList)conn;
}
public MyHandler(Looper L) {
super(L);
}
// 子类必须重写此方法,接受数据
@Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
super.handleMessage(msg);
Bundle b = msg.getData();
String rmsg = b.getString("rmsg");
if ("1".equals(rmsg)) {
// do nothing
List<Map> list = new ArrayList<Map>();
for(int i =0;i<16;i++){
n++;
Map map = new HashMap();
map.put("name", n);
list.add(map);
}
int pageNo = (int)Math.ceil( list.size()/APP_PAGE_SIZE);
for (int i = 0; i < pageNo; i++) {
GridView appPage = new GridView(mContext);
// get the "i" page data
appPage.setAdapter(new AppAdapter(mContext, list, i));
appPage.setNumColumns(2);
appPage.setOnItemClickListener(listener);
mScrollLayout.addView(appPage);
}
//加载分页
pageControl = (PageControlView) findViewById(R.id.pageControl);
pageControl.bindScrollViewGroup(mScrollLayout);
//加载分页数据
dataLoad.bindScrollViewGroup(mScrollLayout);
}
}
}
//分页数据
class DataLoading {
private int count;
public void bindScrollViewGroup(ScrollLayout scrollViewGroup) {
this.count=scrollViewGroup.getChildCount();
scrollViewGroup.setOnScreenChangeListenerDataLoad(new OnScreenChangeListenerDataLoad() {
public void onScreenChange(int currentIndex) {
// TODO Auto-generated method stub
generatePageControl(currentIndex);
}
});
}
private void generatePageControl(int currentIndex){
//如果到最后一页，就加载16条记录
if(count==currentIndex+1){
MyThread m = new MyThread();
new Thread(m).start();
}
}
}
}
Java代码：
package cn.anycall.ju;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import android.app.Activity;
import android.content.ActivityNotFoundException;
import android.content.Context;
import android.content.Intent;
import android.content.pm.ResolveInfo;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.view.KeyEvent;
import android.view.View;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.GridView;
import android.widget.Toast;
import cn.anycall.ju.ScrollLayout.OnScreenChangeListenerDataLoad;
/**
* GridView分页显示安装的应用程序
*/
public class AllAppList extends Activity {
private ScrollLayout mScrollLayout;
private static final float APP_PAGE_SIZE = 4.0f;
private Context mContext;
private PageControlView pageControl;
public MyHandler myHandler;
public int n=0;
private DataLoading dataLoad;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
mContext = this;
setContentView(R.layout.main);
dataLoad = new DataLoading();
mScrollLayout = (ScrollLayout)findViewById(R.id.ScrollLayoutTest);
myHandler = new MyHandler(this,1);
//起一个线程更新数据
MyThread m = new MyThread();
new Thread(m).start();
}
/**
* gridView 的onItemLick响应事件
*/
public OnItemClickListener listener = new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
// TODO Auto-generated method stub
System.out.println("position="+position);
}
};
@Override
protected void onDestroy() {
// TODO Auto-generated method stub
android.os.Process.killProcess(android.os.Process.myPid());
super.onDestroy();
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
// TODO Auto-generated method stub
if (keyCode == KeyEvent.KEYCODE_BACK) {
finish();
return true;
}
return super.onKeyDown(keyCode, event);
}
// 更新后台数据
class MyThread implements Runnable {
public void run() {
try {
Thread.sleep(1000*3);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
String msglist = "1";
Message msg = new Message();
Bundle b = new Bundle();// 存放数据
b.putString("rmsg", msglist);
msg.setData(b);
AllAppList.this.myHandler.sendMessage(msg); // 向Handler发送消息,更新UI
}
}
class MyHandler extends Handler {
private AllAppList mContext;
public MyHandler(Context conn,int a) {
mContext = (AllAppList)conn;
}
public MyHandler(Looper L) {
super(L);
}
// 子类必须重写此方法,接受数据
@Override
public void handleMessage(Message msg) {
// TODO Auto-generated method stub
super.handleMessage(msg);
Bundle b = msg.getData();
String rmsg = b.getString("rmsg");
if ("1".equals(rmsg)) {
// do nothing
List<Map> list = new ArrayList<Map>();
for(int i =0;i<16;i++){
n++;
Map map = new HashMap();
map.put("name", n);
list.add(map);
}
int pageNo = (int)Math.ceil( list.size()/APP_PAGE_SIZE);
for (int i = 0; i < pageNo; i++) {
GridView appPage = new GridView(mContext);
// get the "i" page data
appPage.setAdapter(new AppAdapter(mContext, list, i));
appPage.setNumColumns(2);
appPage.setOnItemClickListener(listener);
mScrollLayout.addView(appPage);
}
//加载分页
pageControl = (PageControlView) findViewById(R.id.pageControl);
pageControl.bindScrollViewGroup(mScrollLayout);
//加载分页数据
dataLoad.bindScrollViewGroup(mScrollLayout);
}
}
}
//分页数据
class DataLoading {
private int count;
public void bindScrollViewGroup(ScrollLayout scrollViewGroup) {
this.count=scrollViewGroup.getChildCount();
scrollViewGroup.setOnScreenChangeListenerDataLoad(new OnScreenChangeListenerDataLoad() {
public void onScreenChange(int currentIndex) {
// TODO Auto-generated method stub
generatePageControl(currentIndex);
}
});
}
private void generatePageControl(int currentIndex){
//如果到最后一页，就加载16条记录
if(count==currentIndex+1){
MyThread m = new MyThread();
new Thread(m).start();
}
}
}
}
Java代码：
package cn.anycall.ju;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import android.content.Context;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import cn.anycall.ju.R;
public class AppAdapter extends BaseAdapter {
private List<Map> mList;
private Context mContext;
public static final int APP_PAGE_SIZE = 4;
private PackageManager pm;
public AppAdapter(Context context, List<Map> list, int page) {
mContext = context;
pm = context.getPackageManager();
mList = new ArrayList<Map>();
int i = page * APP_PAGE_SIZE;
int iEnd = i+APP_PAGE_SIZE;
while ((i<list.size()) && (i<iEnd)) {
mList.add(list.get(i));
i++;
}
}
public int getCount() {
// TODO Auto-generated method stub
return mList.size();
}
public Object getItem(int position) {
// TODO Auto-generated method stub
return mList.get(position);
}
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
Map appInfo = mList.get(position);
AppItem appItem;
if (convertView == null) {
View v = LayoutInflater.from(mContext).inflate(R.layout.app_item, null);
appItem = new AppItem();
appItem.mAppIcon = (ImageView)v.findViewById(R.id.imgdetail);
appItem.mAppName = (TextView)v.findViewById(R.id.tuaninfo);
v.setTag(appItem);
convertView = v;
} else {
appItem = (AppItem)convertView.getTag();
}
// set the icon
appItem.mAppIcon.setImageResource(R.drawable.icon);
// set the app name
appItem.mAppName.setText(appInfo.get("name").toString());
return convertView;
}
/**
* 每个应用显示的内容，包括图标和名称
* @author Yao.GUET
*
*/
class AppItem {
ImageView mAppIcon;
TextView mAppName;
}
}
Java代码：
package cn.anycall.ju;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import android.content.Context;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import cn.anycall.ju.R;
public class AppAdapter extends BaseAdapter {
private List<Map> mList;
private Context mContext;
public static final int APP_PAGE_SIZE = 4;
private PackageManager pm;
public AppAdapter(Context context, List<Map> list, int page) {
mContext = context;
pm = context.getPackageManager();
mList = new ArrayList<Map>();
int i = page * APP_PAGE_SIZE;
int iEnd = i+APP_PAGE_SIZE;
while ((i<list.size()) && (i<iEnd)) {
mList.add(list.get(i));
i++;
}
}
public int getCount() {
// TODO Auto-generated method stub
return mList.size();
}
public Object getItem(int position) {
// TODO Auto-generated method stub
return mList.get(position);
}
public long getItemId(int position) {
// TODO Auto-generated method stub
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
Map appInfo = mList.get(position);
AppItem appItem;
if (convertView == null) {
View v = LayoutInflater.from(mContext).inflate(R.layout.app_item, null);
appItem = new AppItem();
appItem.mAppIcon = (ImageView)v.findViewById(R.id.imgdetail);
appItem.mAppName = (TextView)v.findViewById(R.id.tuaninfo);
v.setTag(appItem);
convertView = v;
} else {
appItem = (AppItem)convertView.getTag();
}
// set the icon
appItem.mAppIcon.setImageResource(R.drawable.icon);
// set the app name
appItem.mAppName.setText(appInfo.get("name").toString());
return convertView;
}
/**
* 每个应用显示的内容，包括图标和名称
* @author Yao.GUET
*
*/
class AppItem {
ImageView mAppIcon;
TextView mAppName;
}
}
Java代码：
package cn.anycall.ju;
import android.content.Context;
import android.util.AttributeSet;
import android.widget.ImageView;
import android.widget.LinearLayout;
import cn.anycall.ju.R;
import cn.anycall.ju.ScrollLayout.OnScreenChangeListener;
public class PageControlView extends LinearLayout {
private Context context;
private int count;
public void bindScrollViewGroup(ScrollLayout scrollViewGroup) {
this.count=scrollViewGroup.getChildCount();
System.out.println("count="+count);
generatePageControl(scrollViewGroup.getCurrentScreenIndex());
scrollViewGroup.setOnScreenChangeListener(new OnScreenChangeListener() {
public void onScreenChange(int currentIndex) {
// TODO Auto-generated method stub
generatePageControl(currentIndex);
}
});
}
public PageControlView(Context context) {
super(context);
this.init(context);
}
public PageControlView(Context context, AttributeSet attrs) {
super(context, attrs);
this.init(context);
}
private void init(Context context) {
this.context=context;
}
private void generatePageControl(int currentIndex) {
this.removeAllViews();
int pageNum = 6; // 显示多少个
int pageNo = currentIndex+1; //第几页
int pageSum = this.count; //总共多少页
if(pageSum>1){
int currentNum = (pageNo % pageNum == 0 ? (pageNo / pageNum) - 1
: (int) (pageNo / pageNum))
* pageNum;
if (currentNum < 0)
currentNum = 0;
if (pageNo > pageNum){
ImageView imageView = new ImageView(context);
imageView.setImageResource(R.drawable.zuo);
this.addView(imageView);
}
for (int i = 0; i < pageNum; i++) {
if ((currentNum + i + 1) > pageSum || pageSum < 2)
break;
ImageView imageView = new ImageView(context);
if(currentNum + i + 1 == pageNo){
imageView.setImageResource(R.drawable.page_indicator_focused);
}else{
imageView.setImageResource(R.drawable.page_indicator);
}
this.addView(imageView);
}
if (pageSum > (currentNum + pageNum)) {
ImageView imageView = new ImageView(context);
imageView.setImageResource(R.drawable.you);
this.addView(imageView);
}
}
}
}
Java代码：
package cn.anycall.ju;
import android.content.Context;
import android.util.AttributeSet;
import android.widget.ImageView;
import android.widget.LinearLayout;
import cn.anycall.ju.R;
import cn.anycall.ju.ScrollLayout.OnScreenChangeListener;
public class PageControlView extends LinearLayout {
private Context context;
private int count;
public void bindScrollViewGroup(ScrollLayout scrollViewGroup) {
this.count=scrollViewGroup.getChildCount();
System.out.println("count="+count);
generatePageControl(scrollViewGroup.getCurrentScreenIndex());
scrollViewGroup.setOnScreenChangeListener(new OnScreenChangeListener() {
public void onScreenChange(int currentIndex) {
// TODO Auto-generated method stub
generatePageControl(currentIndex);
}
});
}
public PageControlView(Context context) {
super(context);
this.init(context);
}
public PageControlView(Context context, AttributeSet attrs) {
super(context, attrs);
this.init(context);
}
private void init(Context context) {
this.context=context;
}
private void generatePageControl(int currentIndex) {
this.removeAllViews();
int pageNum = 6; // 显示多少个
int pageNo = currentIndex+1; //第几页
int pageSum = this.count; //总共多少页
if(pageSum>1){
int currentNum = (pageNo % pageNum == 0 ? (pageNo / pageNum) - 1
: (int) (pageNo / pageNum))
* pageNum;
if (currentNum < 0)
currentNum = 0;
if (pageNo > pageNum){
ImageView imageView = new ImageView(context);
imageView.setImageResource(R.drawable.zuo);
this.addView(imageView);
}
for (int i = 0; i < pageNum; i++) {
if ((currentNum + i + 1) > pageSum || pageSum < 2)
break;
ImageView imageView = new ImageView(context);
if(currentNum + i + 1 == pageNo){
imageView.setImageResource(R.drawable.page_indicator_focused);
}else{
imageView.setImageResource(R.drawable.page_indicator);
}
this.addView(imageView);
}
if (pageSum > (currentNum + pageNum)) {
ImageView imageView = new ImageView(context);
imageView.setImageResource(R.drawable.you);
this.addView(imageView);
}
}
}
}
Java代码：
package cn.anycall.ju;
import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.widget.Scroller;
/**
* 仿Launcher中的WorkSapce，可以左右滑动切换屏幕的类
*
*/
public class ScrollLayout extends ViewGroup {
private static final String TAG = "ScrollLayout";
private Scroller mScroller;
private VelocityTracker mVelocityTracker;
private int mCurScreen;
private int mDefaultScreen = 0;
private static final int TOUCH_STATE_REST = 0;
private static final int TOUCH_STATE_SCROLLING = 1;
private static final int SNAP_VELOCITY = 600;
private int mTouchState = TOUCH_STATE_REST;
private int mTouchSlop;
private float mLastMotionX;
private float mLastMotionY;
private int currentScreenIndex = 0;
public int getCurrentScreenIndex() {
return currentScreenIndex;
}
public void setCurrentScreenIndex(int currentScreenIndex) {
this.currentScreenIndex = currentScreenIndex;
}
public ScrollLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
// TODO Auto-generated constructor stub
}
public ScrollLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
// TODO Auto-generated constructor stub
mScroller = new Scroller(context);
mCurScreen = mDefaultScreen;
mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
// TODO Auto-generated method stub
int childLeft = 0;
final int childCount = getChildCount();
System.out.println("childCount=" + childCount);
for (int i = 0; i < childCount; i++) {
final View childView = getChildAt(i);
if (childView.getVisibility() != View.GONE) {
final int childWidth = childView.getMeasuredWidth();
childView.layout(childLeft, 0, childLeft + childWidth,
childView.getMeasuredHeight());
childLeft += childWidth;
}
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
Log.e(TAG, "onMeasure");
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
final int width = MeasureSpec.getSize(widthMeasureSpec);
final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
if (widthMode != MeasureSpec.EXACTLY) {
throw new IllegalStateException(
"ScrollLayout only canmCurScreen run at EXACTLY mode!");
}
final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
if (heightMode != MeasureSpec.EXACTLY) {
throw new IllegalStateException(
"ScrollLayout only can run at EXACTLY mode!");
}
// The children are given the same width and height as the scrollLayout
final int count = getChildCount();
for (int i = 0; i < count; i++) {
getChildAt(i).measure(widthMeasureSpec, heightMeasureSpec);
}
System.out.println("moving to screen " + mCurScreen);
scrollTo(mCurScreen * width, 0);
}
/**
* According to the position of current layout scroll to the destination
* page.
*/
public void snapToDestination() {
final int screenWidth = getWidth();
final int destScreen = (getScrollX() + screenWidth / 2) / screenWidth;
snapToScreen(destScreen);
}
public void snapToScreen(int whichScreen) {
// get the valid layout page
whichScreen = Math.max(0, Math.min(whichScreen, getChildCount() - 1));
if (getScrollX() != (whichScreen * getWidth())) {
final int delta = whichScreen * getWidth() - getScrollX();
mScroller.startScroll(getScrollX(), 0, delta, 0,
Math.abs(delta) * 2);
mCurScreen = whichScreen;
invalidate(); // Redraw the layout
}
}
public void setToScreen(int whichScreen) {
whichScreen = Math.max(0, Math.min(whichScreen, getChildCount() - 1));
mCurScreen = whichScreen;
scrollTo(whichScreen * getWidth(), 0);
}
public int getCurScreen() {
return mCurScreen;
}
@Override
public void computeScroll() {
// TODO Auto-generated method stub
if (mScroller.computeScrollOffset()) {
scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
postInvalidate();
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
// TODO Auto-generated method stub
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(event);
final int action = event.getAction();
final float x = event.getX();
final float y = event.getY();
switch (action) {
case MotionEvent.ACTION_DOWN:
Log.e(TAG, "event down!");
if (!mScroller.isFinished()) {
mScroller.abortAnimation();
}
mLastMotionX = x;
break;
case MotionEvent.ACTION_MOVE:
int deltaX = (int) (mLastMotionX - x);
mLastMotionX = x;
scrollBy(deltaX, 0);
break;
case MotionEvent.ACTION_UP:
Log.e(TAG, "event : up");
// if (mTouchState == TOUCH_STATE_SCROLLING) {
final VelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.computeCurrentVelocity(1000);
int velocityX = (int) velocityTracker.getXVelocity();
Log.e(TAG, "velocityX:" + velocityX);
if (velocityX > SNAP_VELOCITY && mCurScreen > 0) {
// Fling enough to move left
Log.e(TAG, "snap left");
onScreenChangeListener.onScreenChange(mCurScreen - 1);
System.out.println("mCurScreen=" + (mCurScreen - 1));
snapToScreen(mCurScreen - 1);
} else if (velocityX < -SNAP_VELOCITY
&& mCurScreen < getChildCount() - 1) {
// Fling enough to move right
Log.e(TAG, "snap right");
onScreenChangeListener.onScreenChange(mCurScreen + 1);
//只往右移动才加载数据
onScreenChangeListenerDataLoad.onScreenChange(mCurScreen+1);
snapToScreen(mCurScreen + 1);
} else {
snapToDestination();
}
if (mVelocityTracker != null) {
mVelocityTracker.recycle();
mVelocityTracker = null;
}
// }
mTouchState = TOUCH_STATE_REST;
break;
case MotionEvent.ACTION_CANCEL:
mTouchState = TOUCH_STATE_REST;
break;
}
return true;
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
// TODO Auto-generated method stub
Log.e(TAG, "onInterceptTouchEvent-slop:" + mTouchSlop);
final int action = ev.getAction();
if ((action == MotionEvent.ACTION_MOVE)
&& (mTouchState != TOUCH_STATE_REST)) {
return true;
}
final float x = ev.getX();
final float y = ev.getY();
switch (action) {
case MotionEvent.ACTION_MOVE:
final int xDiff = (int) Math.abs(mLastMotionX - x);
if (xDiff > mTouchSlop) {
mTouchState = TOUCH_STATE_SCROLLING;
}
break;
case MotionEvent.ACTION_DOWN:
mLastMotionX = x;
mLastMotionY = y;
mTouchState = mScroller.isFinished() ? TOUCH_STATE_REST
: TOUCH_STATE_SCROLLING;
break;
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP:
mTouchState = TOUCH_STATE_REST;
break;
}
return mTouchState != TOUCH_STATE_REST;
}
//分页监听
public interface OnScreenChangeListener {
void onScreenChange(int currentIndex);
}
private OnScreenChangeListener onScreenChangeListener;
public void setOnScreenChangeListener(
OnScreenChangeListener onScreenChangeListener) {
this.onScreenChangeListener = onScreenChangeListener;
}
//动态数据监听
public interface OnScreenChangeListenerDataLoad {
void onScreenChange(int currentIndex);
}
private OnScreenChangeListenerDataLoad onScreenChangeListenerDataLoad;
public void setOnScreenChangeListenerDataLoad(OnScreenChangeListenerDataLoad onScreenChangeListenerDataLoad) {
this.onScreenChangeListenerDataLoad = onScreenChangeListenerDataLoad;
}
}
Java代码
package cn.anycall.ju;
import android.content.Context;
import android.graphics.Canvas;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.widget.Scroller;
/**
* 仿Launcher中的WorkSapce，可以左右滑动切换屏幕的类
*
*/
public class ScrollLayout extends ViewGroup {
private static final String TAG = "ScrollLayout";
private Scroller mScroller;
private VelocityTracker mVelocityTracker;
private int mCurScreen;
private int mDefaultScreen = 0;
private static final int TOUCH_STATE_REST = 0;
private static final int TOUCH_STATE_SCROLLING = 1;
private static final int SNAP_VELOCITY = 600;
private int mTouchState = TOUCH_STATE_REST;
private int mTouchSlop;
private float mLastMotionX;
private float mLastMotionY;
private int currentScreenIndex = 0;
public int getCurrentScreenIndex() {
return currentScreenIndex;
}
public void setCurrentScreenIndex(int currentScreenIndex) {
this.currentScreenIndex = currentScreenIndex;
}
public ScrollLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
// TODO Auto-generated constructor stub
}
public ScrollLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
// TODO Auto-generated constructor stub
mScroller = new Scroller(context);
mCurScreen = mDefaultScreen;
mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop();
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
// TODO Auto-generated method stub
int childLeft = 0;
final int childCount = getChildCount();
System.out.println("childCount=" + childCount);
for (int i = 0; i < childCount; i++) {
final View childView = getChildAt(i);
if (childView.getVisibility() != View.GONE) {
final int childWidth = childView.getMeasuredWidth();
childView.layout(childLeft, 0, childLeft + childWidth,
childView.getMeasuredHeight());
childLeft += childWidth;
}
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
Log.e(TAG, "onMeasure");
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
final int width = MeasureSpec.getSize(widthMeasureSpec);
final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
if (widthMode != MeasureSpec.EXACTLY) {
throw new IllegalStateException(
"ScrollLayout only canmCurScreen run at EXACTLY mode!");
}
final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
if (heightMode != MeasureSpec.EXACTLY) {
throw new IllegalStateException(
"ScrollLayout only can run at EXACTLY mode!");
}
// The children are given the same width and height as the scrollLayout
final int count = getChildCount();
for (int i = 0; i < count; i++) {
getChildAt(i).measure(widthMeasureSpec, heightMeasureSpec);
}
System.out.println("moving to screen " + mCurScreen);
scrollTo(mCurScreen * width, 0);
}
/**
* According to the position of current layout scroll to the destination
* page.
*/
public void snapToDestination() {
final int screenWidth = getWidth();
final int destScreen = (getScrollX() + screenWidth / 2) / screenWidth;
snapToScreen(destScreen);
}
public void snapToScreen(int whichScreen) {
// get the valid layout page
whichScreen = Math.max(0, Math.min(whichScreen, getChildCount() - 1));
if (getScrollX() != (whichScreen * getWidth())) {
final int delta = whichScreen * getWidth() - getScrollX();
mScroller.startScroll(getScrollX(), 0, delta, 0,
Math.abs(delta) * 2);
mCurScreen = whichScreen;
invalidate(); // Redraw the layout
}
}
public void setToScreen(int whichScreen) {
whichScreen = Math.max(0, Math.min(whichScreen, getChildCount() - 1));
mCurScreen = whichScreen;
scrollTo(whichScreen * getWidth(), 0);
}
public int getCurScreen() {
return mCurScreen;
}
@Override
public void computeScroll() {
// TODO Auto-generated method stub
if (mScroller.computeScrollOffset()) {
scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
postInvalidate();
}
}
@Override
public boolean onTouchEvent(MotionEvent event) {
// TODO Auto-generated method stub
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
mVelocityTracker.addMovement(event);
final int action = event.getAction();
final float x = event.getX();
final float y = event.getY();
switch (action) {
case MotionEvent.ACTION_DOWN:
Log.e(TAG, "event down!");
if (!mScroller.isFinished()) {
mScroller.abortAnimation();
}
mLastMotionX = x;
break;
case MotionEvent.ACTION_MOVE:
int deltaX = (int) (mLastMotionX - x);
mLastMotionX = x;
scrollBy(deltaX, 0);
break;
case MotionEvent.ACTION_UP:
Log.e(TAG, "event : up");
// if (mTouchState == TOUCH_STATE_SCROLLING) {
final VelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.computeCurrentVelocity(1000);
int velocityX = (int) velocityTracker.getXVelocity();
Log.e(TAG, "velocityX:" + velocityX);
if (velocityX > SNAP_VELOCITY && mCurScreen > 0) {
// Fling enough to move left
Log.e(TAG, "snap left");
onScreenChangeListener.onScreenChange(mCurScreen - 1);
System.out.println("mCurScreen=" + (mCurScreen - 1));
snapToScreen(mCurScreen - 1);
} else if (velocityX < -SNAP_VELOCITY
&& mCurScreen < getChildCount() - 1) {
// Fling enough to move right
Log.e(TAG, "snap right");
onScreenChangeListener.onScreenChange(mCurScreen + 1);
//只往右移动才加载数据
onScreenChangeListenerDataLoad.onScreenChange(mCurScreen+1);
snapToScreen(mCurScreen + 1);
} else {
snapToDestination();
}
if (mVelocityTracker != null) {
mVelocityTracker.recycle();
mVelocityTracker = null;
}
// }
mTouchState = TOUCH_STATE_REST;
break;
case MotionEvent.ACTION_CANCEL:
mTouchState = TOUCH_STATE_REST;
break;
}
return true;
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
// TODO Auto-generated method stub
Log.e(TAG, "onInterceptTouchEvent-slop:" + mTouchSlop);
final int action = ev.getAction();
if ((action == MotionEvent.ACTION_MOVE)
&& (mTouchState != TOUCH_STATE_REST)) {
return true;
}
final float x = ev.getX();
final float y = ev.getY();
switch (action) {
case MotionEvent.ACTION_MOVE:
final int xDiff = (int) Math.abs(mLastMotionX - x);
if (xDiff > mTouchSlop) {
mTouchState = TOUCH_STATE_SCROLLING;
}
break;
case MotionEvent.ACTION_DOWN:
mLastMotionX = x;
mLastMotionY = y;
mTouchState = mScroller.isFinished() ? TOUCH_STATE_REST
: TOUCH_STATE_SCROLLING;
break;
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP:
mTouchState = TOUCH_STATE_REST;
break;
}
return mTouchState != TOUCH_STATE_REST;
}
//分页监听
public interface OnScreenChangeListener {
void onScreenChange(int currentIndex);
}
private OnScreenChangeListener onScreenChangeListener;
public void setOnScreenChangeListener(
OnScreenChangeListener onScreenChangeListener) {
this.onScreenChangeListener = onScreenChangeListener;
}
//动态数据监听
public interface OnScreenChangeListenerDataLoad {
void onScreenChange(int currentIndex);
}
private OnScreenChangeListenerDataLoad onScreenChangeListenerDataLoad;
public void setOnScreenChangeListenerDataLoad(OnScreenChangeListenerDataLoad onScreenChangeListenerDataLoad) {
this.onScreenChangeListenerDataLoad = onScreenChangeListenerDataLoad;
}
}
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView android:layout_width="fill_parent"
android:layout_height="wrap_content" android:text="仿淘宝聚划算"/>
<RelativeLayout
android:id="@+id/myView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<cn.anycall.ju.ScrollLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/ScrollLayoutTest"
android:layout_width="fill_parent"
android:layout_height="fill_parent" android:background="#000000" >
</cn.anycall.ju.ScrollLayout>
<cn.anycall.ju.PageControlView
android:id="@+id/pageControl"
android:layout_width="fill_parent"
android:layout_height="40px"
android:background="#8f00000f"
android:layout_alignParentBottom="true"
android:gravity="center"/>
</RelativeLayout>
</LinearLayout>
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<TextView android:layout_width="fill_parent"
android:layout_height="wrap_content" android:text="仿淘宝聚划算"/>
<RelativeLayout
android:id="@+id/myView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<cn.anycall.ju.ScrollLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/ScrollLayoutTest"
android:layout_width="fill_parent"
android:layout_height="fill_parent" android:background="#000000" >
</cn.anycall.ju.ScrollLayout>
<cn.anycall.ju.PageControlView
android:id="@+id/pageControl"
android:layout_width="fill_parent"
android:layout_height="40px"
android:background="#8f00000f"
android:layout_alignParentBottom="true"
android:gravity="center"/>
</RelativeLayout>
</LinearLayout>
app_item.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
<RelativeLayout android:id="@+id/alllayout" android:layout_width="wrap_content" android:layout_height="wrap_content">
<RelativeLayout android:id="@+id/imglayout" android:layout_width="160dp" android:layout_height="160dp" android:background="@drawable/mer_border">
<ImageView android:id="@+id/imgdetail" android:layout_width="145dp" android:layout_height="145dp" android:layout_margin="8dp" />
<TextView android:id="@+id/price" android:layout_width="180dp" android:layout_height="wrap_content" android:text="12345" android:layout_alignParentBottom="true" android:background="#C02000" android:textColor="#FFFFFF"/>
<TextView android:id="@+id/look" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="去看看" android:layout_alignParentBottom="true" android:layout_alignParentRight="true" android:background="#C02000" android:textColor="#FFFFFF"/>
</RelativeLayout>
<TextView android:id="@+id/tuaninfo" android:layout_width="fill_parent"
android:layout_height="wrap_content" android:textSize="16dp"
android:maxLines="2" android:layout_below="@id/imglayout"
android:ellipsize="end" android:text="dddddddddd"/>"
</RelativeLayout>
</RelativeLayout>
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
>
<RelativeLayout android:id="@+id/alllayout" android:layout_width="wrap_content" android:layout_height="wrap_content">
<RelativeLayout android:id="@+id/imglayout" android:layout_width="160dp" android:layout_height="160dp" android:background="@drawable/mer_border">
<ImageView android:id="@+id/imgdetail" android:layout_width="145dp" android:layout_height="145dp" android:layout_margin="8dp" />
<TextView android:id="@+id/price" android:layout_width="180dp" android:layout_height="wrap_content" android:text="12345" android:layout_alignParentBottom="true" android:background="#C02000" android:textColor="#FFFFFF"/>
<TextView android:id="@+id/look" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="去看看" android:layout_alignParentBottom="true" android:layout_alignParentRight="true" android:background="#C02000" android:textColor="#FFFFFF"/>
</RelativeLayout>
<TextView android:id="@+id/tuaninfo" android:layout_width="fill_parent"
android:layout_height="wrap_content" android:textSize="16dp"
android:maxLines="2" android:layout_below="@id/imglayout"
android:ellipsize="end" android:text="dddddddddd"/>"
</RelativeLayout>
</RelativeLayout>
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希望本文所述对大家Android程序设计有所帮助。