在开发andorid程序的时候,难免会牵扯到退出整个应用程序的情况,怎么完全退出呢?请参阅下面的关键代码:
- import java.util.LinkedList;
- import java.util.List;
- import android.app.Activity;
- import android.app.AlertDialog;
- import android.app.Application;
- import android.content.DialogInterface;
- import android.content.Intent;
- public class SysApplication
extends Application { - private List<Activity> mList =
new LinkedList<Activity>(); - private static SysApplication instance;
- private SysApplication() {
- }
- public synchronized
static SysApplication getInstance() { - if (null == instance) {
- instance = new SysApplication();
- }
- return instance;
- }
- // add Activity
- public void addActivity(Activity activity) {
- mList.add(activity);
- }
- public void exit() {
- try {
- for (Activity activity : mList) {
- if (activity !=
null) - activity.finish();
- }
- } catch (Exception e) {
- e.printStackTrace();
- } finally {
- System.exit(0);
- }
- }
- @Override
- public void onLowMemory() {
- super.onLowMemory();
- System.gc();
- }
- }
public class SysApplication extends Application {
private List<Activity> mList = new LinkedList<Activity>();
private static SysApplication instance;
private SysApplication() {
}
public synchronized static SysApplication getInstance() {
if (null == instance) {
instance = new SysApplication();
}
return instance;
}
// add Activity
public void addActivity(Activity activity) {
mList.add(activity);
}
public void exit() {
try {
for (Activity activity : mList) {
if (activity != null)
activity.finish();
}
} catch (Exception e) {
e.printStackTrace();
} finally {
System.exit(0);
}
}
@Override
public void onLowMemory() {
super.onLowMemory();
System.gc();
}
}在每个Activity的onCreate方法中添加类似代码:
- public void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- SysApplication.getInstance().addActivity(this);
- }
在需要退出程序的时候,调用:
- SysApplication.getInstance().exit();
简而言之,通过单例模式把每个Activity 的引用添加到一个全局链表中,每次退出程序调用System.exit(0)