Android自带emoji表情的使用方法详解
作者:mChenys
什么是emoji表情
emoji表情是一种表情符号,在代码中它现在其实是一组遵循Unicode的编码,即每一个表情符号都对应了一个Unicode编码。更进一步说,emoji表情实际上是一组Unicode编码与一组表情描述之间的对应。注意,这里所说的不是表情图片,而是表情描述。那么图片的实现是由谁来负责的呢?图片是由各个系统或者软件针对统一的表情描述来各自实现的,他们都遵循统一的Unicode编码规范。也就是说Unicode编码其所对应的表情描述是统一的,是所有人都要共同遵守的一套标准或者规范,而具体的表情图片则可能因平台的不同而产生差异。
首先你得先从网上收集一套emoji的Unicode编码,例如这个网站Emoji Unicode Tables
该网站上面给出了每个emoji表情的图片,描述,Unicode编码的对照表,点击表中每一项emoji可看到如下所示:
红色框框就是我们要的值.在java中的Unicode表示就是:”\ud83d\ude01”,该编码字符可以直接被Android的TextView和EditText控件识别成对应的emoji表情.
本次demo中展示了从 “\ud83d\ude00” - “\ud83c\udf7c”这216个emoji表情.
效果图如下:
关于emoji编码的存放和获取
由于有216个emoji编码字符串,因此我把它整理到一个json数组中,然后保存到assets目录下.
然后获取的话,通过如下代码方式获取:
/** * 从assets目录下获取所有表情 * * @return */ public String[] getEmojis() { BufferedReader br = null; String emojis[] = null; try { InputStream is = mContext.getAssets().open("emoji.json"); StringBuffer sb = new StringBuffer(); br = new BufferedReader(new InputStreamReader(is)); String line = null; while (null != (line = br.readLine())) { sb.append(line).append("\r\n"); } JSONArray emojiArray = new JSONArray(sb.toString()); if (null != emojiArray && emojiArray.length() > 0) { emojis = new String[emojiArray.length()]; for (int i = 0; i < emojiArray.length(); i++) { emojis[i] = emojiArray.optString(i); } } } catch (Exception e) { e.printStackTrace(); } finally { if (null != br) { try { br.close(); } catch (IOException e) { e.printStackTrace(); } } } return emojis; }
表情组设计
通过上面的效果图也可以看得出,216个emoji表情被分成了8组,每组27个emoji+1个删除按钮.
实现这个效果也很简单,就是通过ViewPager来展示每一组emoji,而每一组emoji里面又是一个GridView控件,里面的item就是一个个的TextView.
每一组emoji页面的创建代码如下:
/** * 获取所有表情GridView页面的集合 * * @return */ public List<View> getPagerList() { List<View> pagers = null; String[] eachPageEmojis = null; if (null != mEmojis && mEmojis.length > 0) { pagers = new ArrayList<>(); int pageCount = mEmojis.length / 27;//共8页表情 for (int i = 0; i < pageCount; i++) { GridView gridView = new GridView(mContext); gridView.setNumColumns(7); gridView.setSelector(new ColorDrawable(Color.TRANSPARENT)); gridView.setCacheColorHint(Color.TRANSPARENT); gridView.setStretchMode(GridView.STRETCH_COLUMN_WIDTH); gridView.setGravity(Gravity.CENTER); eachPageEmojis = new String[28]; //总共216个表情字符,索引变化为:0-26,27-53,54-80,81-107,108-134,135-161,162-188,189-215 System.arraycopy(mEmojis, i * 27, eachPageEmojis, 0, 27); eachPageEmojis[27] = "del";//第28是删除按钮,用特殊字符串表示 gridView.setAdapter(new EmojiGvAdapter(mContext, eachPageEmojis)); //点击表情监听 gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { //获取选中的表情字符 String emoji = (String) parent.getAdapter().getItem(position); if (null != mEmojiClickListener) { mEmojiClickListener.onClick(emoji); } } }); pagers.add(gridView); } } return pagers; }
MainActivity的布局和代码
主布局是一个垂直的线性布局,大体分2部分,表情面板和上面的视图界面
<?xml version="1.0" encoding="utf-8"?> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" > <!--显示表情的TextView--> <TextView android:id="@+id/tv_info" android:layout_width="match_parent" android:layout_height="0dp" android:layout_weight="1" android:padding="15dp" /> <!--表情,输入框,发送--> <LinearLayout android:layout_width="match_parent" android:layout_height="wrap_content"> <Button android:id="@+id/btn_emoji" android:layout_width="55dp" android:layout_height="wrap_content" android:text="表情"/> <EditText android:id="@+id/edt_msg" android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1"/> <Button android:id="@+id/btn_send" android:layout_width="55dp" android:layout_height="wrap_content" android:text="发送"/> </LinearLayout> <!--表情面板--> <FrameLayout android:id="@+id/fl_emoji" android:layout_width="match_parent" android:layout_height="wrap_content" android:visibility="gone" > <android.support.v4.view.ViewPager android:id="@+id/vp_emoji" android:layout_width="match_parent" android:layout_height="wrap_content" android:paddingTop="10dp" /> <LinearLayout android:id="@+id/ll_point" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_gravity="bottom" android:layout_marginBottom="10dp" android:gravity="center" android:orientation="horizontal"></LinearLayout> </FrameLayout> </LinearLayout>
MainActivity代码如下:
public class MainActivity extends AppCompatActivity { private static final String TAG = "MainActivity"; private Button mEmojiBtn, mSendBtn;//表情按钮和发送按钮 private EditText mMsgEdt;//输入框 private TextView mInfoTv;//展示界面 private ViewPager mEmojiVp;//表情ViewPager private FrameLayout mEmojiFl;//表情面板 private LinearLayout mVpPointLl;//表情ViewPager指示器 //输入法和表情平滑切换的辅助类 private EmotionKeyboardSwitchHelper mEmotionKeyboardSwitchHelper; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mEmotionKeyboardSwitchHelper = EmotionKeyboardSwitchHelper.with(this); initView(); initListener(); } private void initListener() { mSendBtn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { mInfoTv.append(mMsgEdt.getText() + "\r\n"); mMsgEdt.setText(""); } }); mEmotionKeyboardSwitchHelper.bind(mInfoTv, mMsgEdt, mEmojiBtn, mEmojiFl); } private void initView() { mEmojiBtn = (Button) findViewById(R.id.btn_emoji); mSendBtn = (Button) findViewById(R.id.btn_send); mMsgEdt = (EditText) findViewById(R.id.edt_msg); mInfoTv = (TextView) findViewById(R.id.tv_info); mEmojiVp = (ViewPager) findViewById(R.id.vp_emoji); mEmojiFl = (FrameLayout) findViewById(R.id.fl_emoji); mVpPointLl = (LinearLayout) findViewById(R.id.ll_point); initViewPager(); } /** * 设置ViewPager表情 */ private void initViewPager() { EmojiVpAdapter adapter = new EmojiVpAdapter(this); mEmojiVp.setAdapter(adapter); //表情点击监听 adapter.setOnEmojiClickListener(new EmojiVpAdapter.OnEmojiClickListener() { @Override public void onClick(String emoji) { if ("del".equals(emoji)) { //表示点击的是删除按钮 KeyEvent event = new KeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_DEL); mMsgEdt.onKeyDown(KeyEvent.KEYCODE_DEL, event); } else { mMsgEdt.append(emoji); } } }); mEmojiVp.setCurrentItem(0); //关联指示器点 adapter.setupWithPagerPoint(mEmojiVp, mVpPointLl); } @Override public void onBackPressed() { if (mEmotionKeyboardSwitchHelper.onBackPress()) { super.onBackPressed(); } } }
emoji ViewPager
public class EmojiVpAdapter extends PagerAdapter { private Context mContext; private String[] mEmojis;//216个表情字符 private List<View> mPagers;//展示的页面 private OnEmojiClickListener mEmojiClickListener;//表情点击监听接口 public EmojiVpAdapter(Context ctx) { this.mContext = ctx; this.mEmojis = getEmojis(); this.mPagers = getPagerList(); } @Override public int getCount() { return null == mPagers ? 0 : mPagers.size(); } @Override public boolean isViewFromObject(View view, Object object) { return view == object; } @Override public Object instantiateItem(ViewGroup container, int position) { View view = mPagers.get(position); if (null != view) { container.addView(view); } return view; } @Override public void destroyItem(ViewGroup container, int position, Object object) { container.removeView((View) object); } /** * 从assets目录下获取所有表情 * * @return */ public String[] getEmojis() { BufferedReader br = null; String emojis[] = null; try { InputStream is = mContext.getAssets().open("emoji.json"); StringBuffer sb = new StringBuffer(); br = new BufferedReader(new InputStreamReader(is)); String line = null; while (null != (line = br.readLine())) { sb.append(line).append("\r\n"); } JSONArray emojiArray = new JSONArray(sb.toString()); if (null != emojiArray && emojiArray.length() > 0) { emojis = new String[emojiArray.length()]; for (int i = 0; i < emojiArray.length(); i++) { emojis[i] = emojiArray.optString(i); } } } catch (Exception e) { e.printStackTrace(); } finally { if (null != br) { try { br.close(); } catch (IOException e) { e.printStackTrace(); } } } return emojis; } /** * 获取所有表情GridView页面的集合 * * @return */ public List<View> getPagerList() { List<View> pagers = null; String[] eachPageEmojis = null; if (null != mEmojis && mEmojis.length > 0) { pagers = new ArrayList<>(); int pageCount = mEmojis.length / 27;//共8页表情 for (int i = 0; i < pageCount; i++) { GridView gridView = new GridView(mContext); gridView.setNumColumns(7); gridView.setSelector(new ColorDrawable(Color.TRANSPARENT)); gridView.setCacheColorHint(Color.TRANSPARENT); gridView.setStretchMode(GridView.STRETCH_COLUMN_WIDTH); gridView.setGravity(Gravity.CENTER); eachPageEmojis = new String[28]; //总共216个表情字符,索引变化为:0-26,27-53,54-80,81-107,108-134,135-161,162-188,189-215 System.arraycopy(mEmojis, i * 27, eachPageEmojis, 0, 27); eachPageEmojis[27] = "del";//第28是删除按钮,用特殊字符串表示 gridView.setAdapter(new EmojiGvAdapter(mContext, eachPageEmojis)); //点击表情监听 gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { //获取选中的表情字符 String emoji = (String) parent.getAdapter().getItem(position); if (null != mEmojiClickListener) { mEmojiClickListener.onClick(emoji); } } }); pagers.add(gridView); } } return pagers; } /** * 关联指示器点 * * @param viewPager * @param pointLayout */ public void setupWithPagerPoint(ViewPager viewPager, final LinearLayout pointLayout) { //初始表情指示器 int pageCount = getCount(); for (int i = 0; i < pageCount; i++) { ImageView point = new ImageView(mContext); point.setImageResource(R.drawable.shape_vp_dot_unselected); LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(-2, -2); params.rightMargin = (int) mContext.getResources().getDimension(R.dimen.dp10); if (i == 0) { point.setImageResource(R.drawable.shape_vp_dot_selected); } pointLayout.addView(point, params); } viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() { @Override public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) { } @Override public void onPageSelected(int position) { //切换指示器 if (null != pointLayout && pointLayout.getChildCount() > 0) { for (int i = 0; i < pointLayout.getChildCount(); i++) { ((ImageView) pointLayout.getChildAt(i)).setImageResource(R.drawable.shape_vp_dot_unselected); } ((ImageView) pointLayout.getChildAt(position)).setImageResource(R.drawable.shape_vp_dot_selected); } } @Override public void onPageScrollStateChanged(int state) { } }); } /** * 表情点击监听器 */ public interface OnEmojiClickListener { void onClick(String emoji); } public void setOnEmojiClickListener(OnEmojiClickListener l) { this.mEmojiClickListener = l; } }
emoji GridView
public class EmojiGvAdapter extends BaseAdapter { private Context mContext; private String[] mEmojis; public EmojiGvAdapter(Context context, String[] eachPageEmojis) { this.mContext = context; this.mEmojis = eachPageEmojis; } @Override public int getCount() { return null == mEmojis ? 0 : mEmojis.length; } @Override public String getItem(int position) { return null == mEmojis ? "" : mEmojis[position]; } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { ViewHolder holder = null; if (null == convertView) { holder = new ViewHolder(); convertView = View.inflate(mContext, R.layout.item_emoji, null); holder.emojiTv = (TextView) convertView.findViewById(R.id.tv_emoji); convertView.setTag(holder); } else { holder = (ViewHolder) convertView.getTag(); } if (position == 27) { //第28个显示删除按钮 holder.emojiTv.setBackgroundResource(R.drawable.ic_emojis_delete); FrameLayout.LayoutParams lp = (FrameLayout.LayoutParams) holder.emojiTv.getLayoutParams(); lp.bottomMargin = (int) mContext.getResources().getDimension(R.dimen.dp12); } else { holder.emojiTv.setText(getItem(position)); } return convertView; } private static class ViewHolder { private TextView emojiTv; } }
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持脚本之家。