在应用中肯定遇到有这样的问题，在应用中在于多的Activity中跳转，这些Activity都存在Activity栈中了。所以按返回键的时候都是一个一个的将原来的Activity弹回。如果我们想捕获到back事件之后直接退出整个程序，就要思考了。特别是2.2之后的安全机制考虑之后。
粘贴点代码，以备之后使用。
Java代码
package com.jftt;
import Android.app.Activity;
import android.app.ActivityManager;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class TestLogout extends Activity {
public static final String TAG = TestLogout.class.getSimpleName();
private Button btn1;
private Button btn2;
private Button btn3;
private Button btn4;
private Button btn5;
private Button go;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.logout);
this.onStart();
btn1 = (Button) findViewById(R.id.btn1);
btn1.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
android.os.Process.killProcess(android.os.Process.myPid()); // 获取PID
}
});
btn2 = (Button) findViewById(R.id.btn2);
btn2.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
System.exit(0); // 常规java、c#的标准退出法，返回值为0代表正常退出
}
});
btn3 = (Button) findViewById(R.id.btn3);
btn3.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Log.i(TAG, "close " + getPackageName());
ActivityManager am = (ActivityManager) TestLogout.this .getSystemService(Context.ACTIVITY_SERVICE);
am.restartPackage(getPackageName());
// am.killBackgroundProcesses(getPackageName());
}
});
btn4 = (Button) findViewById(R.id.btn4);
btn4.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent();
// intent.setClass((B或者C或者D).this, A.class);
intent.setClass(TestLogout.this, TestLogout.class);
intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
intent.putExtra("flag", 1);
startActivity(intent);
}
});
//此方法并未杀掉应用程序 而是把launcher调起
btn5 = (Button) findViewById(R.id.btn5);
btn5.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent startMain = new Intent(Intent.ACTION_MAIN);
startMain.addCategory(Intent.CATEGORY_HOME);
startMain.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivity(startMain);
}
});
go = (Button) findViewById(R.id.go);
go.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(TestLogout.this, TestLogout.class);
// intent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(intent);
}
});
}
protected void onStart() {
super.onStart();
Intent intent = getIntent();
int x = intent.getIntExtra("flag", -1);
if (x == 0) {
finish();
}
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {
AlertDialog.Builder alertbBuilder = new AlertDialog.Builder(this);
alertbBuilder.setIcon(R.drawable.icon).setTitle("友情提示...").setMessage("你确定要离开吗？");
alertbBuilder.setPositiveButton("确定", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
// 结束这个Activity
int nPid = android.os.Process.myPid();
android.os.Process.killProcess(nPid);
}
});
alertbBuilder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
}).create();
alertbBuilder.show();
}
return true;
}
}
Java代码
package com.jftt;
import java.util.Stack;
import Android.app.Activity;
public class ActiivtyStack {
private static Stack<Activity> mActivityStack;
private static ActiivtyStack instance;
private ActiivtyStack() {
}
public static ActiivtyStack getScreenManager() {
if (instance == null) {
instance = new ActiivtyStack();
}
return instance;
}
// 退出栈顶Activity
public void popActivity(Activity activity) {
if (activity != null) {
activity.finish();
mActivityStack.remove(activity);
// mActivityStack.pop();
activity = null;
}
}
// 获得当前栈顶Activity
public Activity currentActivity() {
Activity activity = mActivityStack.lastElement();
// Activity activity = mActivityStack.pop();
return activity;
}
// 将当前Activity推入栈中
public void pushActivity(Activity activity) {
if (mActivityStack == null) {
mActivityStack = new Stack<Activity>();
}
mActivityStack.add(activity);
// mActivityStack.push(activity);
}
// 退出栈中所有Activity
public void popAllActivityExceptOne(Class<Activity> cls) {
while (true) {
Activity activity = currentActivity();
if (activity == null) {
break;
}
if (activity.getClass().equals(cls)) {
break;
}
popActivity(activity);
}
}
}
logout.xml
Xml代码
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
>
<Button
android:id="@+id/btn1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="logout button1"
/>
<Button
android:id="@+id/btn2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="logout button2"
/>
<Button
android:id="@+id/btn3"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="logout button3"
/>
<Button
android:id="@+id/btn4"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="go to first"
/>
<Button
android:id="@+id/btn5"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="go to launcher"
/>
<Button
android:id="@+id/go"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="go another activity"
/>
<!--
<EditText
android:id="@+id/et01"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
/>
<ImageView
android:id="@+id/iv01"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
-->
</LinearLayout>
manifest中的权限：
Xml代码
<uses-permission android:name="android.permission.KILL_BACKGROUND_PROCESSES" />
<uses-permission android:name="android.permission.RESTART_PACKAGE" />
