android开发之欢迎界面的小例子
作者：
首先你得写好xml文件，这也是最主要的。
然后，在activity中加入一个线程，延时2秒，用来跳转到主界面。
activity中线程代码如下：(顺便检测一下网络是否打开）
[java]
@Override
protected void onStart() {
super.onStart();
if(<SPAN style="COLOR: #ff0000">isNetworkConnected()</SPAN>){
new Thread(){
@Override
public void run() {
try {
Thread.sleep(2000);
Intent intent = new Intent(<SPAN style="COLOR: #ff0000">SplashActivity.this</SPAN>,<SPAN style="COLOR: #ff0000">CompusAssistMain.class</SPAN>);
startActivity(intent);
finish();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}.start();
}else{
//弹出对话框 让用户设置网络
AlertDialog.Builder builder = new Builder(this);
builder.setTitle("设置网络");
builder.setMessage("网络错误请设置网络");
builder.setPositiveButton("设置网络", new OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent();
intent.setClassName(<SPAN style="COLOR: #ff6666">"com.android.settings"</SPAN>, <SPAN style="COLOR: #ff6666">"com.android.settings.WirelessSettings"</SPAN>);
startActivity(intent);
}
});
builder.setNegativeButton("取消", new OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
finish();
}
});
builder.create().show();
}
}
@Override
protected void onStart() {
super.onStart();
if(isNetworkConnected()){
new Thread(){
@Override
public void run() {
try {
Thread.sleep(2000);
Intent intent = new Intent(SplashActivity.this,CompusAssistMain.class);
startActivity(intent);
finish();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}.start();
}else{
//弹出对话框 让用户设置网络
AlertDialog.Builder builder = new Builder(this);
builder.setTitle("设置网络");
builder.setMessage("网络错误请设置网络");
builder.setPositiveButton("设置网络", new OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
Intent intent = new Intent();
intent.setClassName("com.android.settings", "com.android.settings.WirelessSettings");
startActivity(intent);
}
});
builder.setNegativeButton("取消", new OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
finish();
}
});
builder.create().show();
}
}检测网络的类isNetWorkConnected():
[java]
<SPAN style="WHITE-SPACE: pre"> </SPAN>/**
* 判断系统的网络是否可用
* @return
*/
private boolean isNetworkConnected(){
ConnectivityManager cm = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);
NetworkInfo info =cm.getActiveNetworkInfo();
if(info!=null&&info.isConnected()){
return true;
}else {
return false ;
}
/**
* 判断系统的网络是否可用
* @return
*/
private boolean isNetworkConnected(){
ConnectivityManager cm = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);
NetworkInfo info =cm.getActiveNetworkInfo();
if(info!=null&&info.isConnected()){
return true;
}else {
return false ;
}
这样就完成了一个欢迎界面，给自已的应用加点色彩。当然还要添加配置在Manifest文件中
[html]
<activity
android:name="com.yan.compusassist.SplashActivity"
android:label="@string/application_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity
android:name="com.yan.compusassist.SplashActivity"
android:label="@string/application_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
这样它就会打开应用，启动第一个activity 界面。