android - 我们如何知道 Android 应用程序已关闭？

Question

I am developing an Android Application to download an .mp3 file from server. When downloading is finished the file will be stored in a DIFFRENT EXTENSION (.srt) . and when the user clicked on the play button the file's EXTENSION will be changed back into .mp3 and play And when the user exit's the Application the file will go back to the (.srt) format.

一切正常。但现在如果用户关闭应用程序而不按 BackKey，扩展将是相同的。

我的代码是

public void onBackPressed() {
        new AlertDialog.Builder(this)
                .setTitle("Really Exit?")
                .setMessage("Are you sure you want to exit?")
                .setNegativeButton(android.R.string.no, null)
                .setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {

                    public void onClick(DialogInterface arg0, int arg1) {
                        File file  = new File(Environment.getExternalStorageDirectory().toString() + "/Jithin's/downloadedfile.mp3"); // handler to your ZIP file
                        File file2 = new File(Environment.getExternalStorageDirectory().toString() + "/Jithin's/downloadedfile.srt");
                        // destination dir of your file
                        boolean success = file.renameTo(file2);
                       System.exit(0);

                         }
                }).create().show();

    }

如果用户没有通过正确的方式退出，退出按钮内的功能将不起作用。

Answer 1

从 Android Studio 文件 -> 新建 -> 服务 -> 服务创建新服务 然后像这样重写 onStartCommand 方法

@Override
public int onStartCommand(Intent intent, int flags, int startId) {
File file  = new File(Environment.getExternalStorageDirectory().toString() + "/Jithin's/downloadedfile.mp3"); // handler to your ZIP file
File file2 = new File(Environment.getExternalStorageDirectory().toString() + "/Jithin's/downloadedfile.srt");
 // destination dir of your file
 boolean success = file.renameTo(file2);
 MyService.this.stopService(intent);
    return super.onStartCommand(intent, flags, startId);
 }

然后你可以通过这个从你的 Activity 的 onstop 方法启动它

protected void onStop(){
super.onStop();
Intent intent = new Intent(MainActivity.this,MyService.class);
startService(intent);
}

或者你可以在 onStop 方法中执行相同的操作，如下所示

protected void onStop(){
super.onStop();
File file  = new File(Environment.getExternalStorageDirectory().toString() + "/Jithin's/downloadedfile.mp3"); // handler to your ZIP file
 File file2 = new File(Environment.getExternalStorageDirectory().toString() + "/Jithin's/downloadedfile.srt");
 // destination dir of your file
 boolean success = file.renameTo(file2);
 }