如何在android中手动结束一个应用程序

Question

当用户从主屏幕按下返回键时，我想结束我的应用程序。我尝试使用System.exit(0)，但它似乎不工作。

我要怎么做才能手动结束我的应用程序?

    package com.mahavega.qcdemo;

import com.mahavega.qcdemo.R;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.GestureDetector;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.view.View.OnClickListener;
import android.widget.ImageView;
public class MainActivity extends Activity implements OnClickListener {
     private GestureDetector gestureDetector;
        View.OnTouchListener gestureListener;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        gestureDetector = new GestureDetector(this, new MyGestureDetector());
        gestureListener = new View.OnTouchListener() {
            public boolean onTouch(View v, MotionEvent event) {
                return gestureDetector.onTouchEvent(event);
            }
        };
        ImageView ad = (ImageView) findViewById(R.id.imageView1);
        ImageView im2 = (ImageView) findViewById(R.id.imageView2);
        ImageView im3 = (ImageView) findViewById(R.id.imageView3);
        ImageView im4 = (ImageView) findViewById(R.id.imageView4);
        ImageView im5 = (ImageView) findViewById(R.id.imageView5);
        ad.setOnClickListener(MainActivity.this);
        im2.setOnTouchListener(gestureListener);
        im2.setOnClickListener(MainActivity.this); 
        im3.setOnTouchListener(gestureListener);
        im3.setOnClickListener(MainActivity.this); 
        im4.setOnTouchListener(gestureListener);
        im4.setOnClickListener(MainActivity.this); 
        im5.setOnTouchListener(gestureListener);
        im5.setOnClickListener(MainActivity.this); 
        ad.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                startActivity(new Intent(MainActivity.this, Adds.class));
            }
        });
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
    class MyGestureDetector extends SimpleOnGestureListener {
        @Override
        public boolean onFling (MotionEvent e1, MotionEvent e2, float velocityX,    float velocityY)
        {
            float sensitvity = 50;
            if((e1.getX() - e2.getX()) < sensitvity){
                startActivity(new Intent(MainActivity.this, Login.class));
            }
            return super.onFling(e1, e2, velocityX, velocityY);
        }
    }
    @Override
    public void onClick(View v) {
        // TODO Auto-generated method stub

    }
    @Override
    public void onBackPressed() {
        // TODO Auto-generated method stub
        System.exit(0);
        finish();
        super.onBackPressed();
        }

   }

这是我的全部代码

Answer 1

根据你运行/构建的Android版本，你可能需要给你的Activity添加一点帮助来捕捉后退按钮。添加这个函数可以提供以下帮助:

            @Override 
            public boolean onKeyDown(int keyCode, KeyEvent event)  { 
                if (Integer.parseInt(android.os.Build.VERSION.SDK) < 5 
                        && keyCode == KeyEvent.KEYCODE_BACK 
                        && event.getRepeatCount() == 0) { 
                    onBackPressed(); 
                } 
                return true; 
            } 

Answer 2

在您的Activity呼叫finish()。此处参考https://developer.android.com/reference/android/app/Activity.html#finish()

Answer 3

public static final void android.os.Process.killProcess(int pid)

简单，工作和做你想要的。但请注意，不建议在Android上显式退出应用程序。(普通的GUI应用程序只是在最上面的Activity上调用finish()，并让操作系统决定何时退出应用程序进程。)

Answer 4

调用moveTaskToBack(true)在你的Activity(它退出你的应用程序，但不销毁它)