android开发之欢迎界面的小例子

2020-04-11 12:16:42

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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]

复制代码代码如下:

@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();
 }
 }

@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]

复制代码代码如下:

/**
 * 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]

复制代码代码如下: