Android 程序退出确认功能开发

         程序都需要退出确认功能，方式有很多种。不多说。

方法一：

@Override
	public boolean dispatchKeyEvent(KeyEvent event) {
		if (event.getKeyCode() == KeyEvent.KEYCODE_BACK) {
			if (event.getAction() == KeyEvent.ACTION_DOWN
					&& event.getRepeatCount() == 0) {
				this.confirmExit();// 这是自定义的代码
			}
			return true;
		}

		return super.dispatchKeyEvent(event);
	}

	private void confirmExit() {
		// 退出确认
		AlertDialog.Builder ad = new AlertDialog.Builder(PGisMainActivity.this);
		ad.setTitle("退出");
		ad.setIcon(R.drawable.ic_launcher);
		ad.setMessage("是否退出系统?");
		ad.setPositiveButton("是", new DialogInterface.OnClickListener() {
			// 退出按钮
			@Override
			public void onClick(DialogInterface dialog, int i) {
				isRunning = false;
				
			}
		});
		ad.setNegativeButton("否", new DialogInterface.OnClickListener() {
			@Override
			public void onClick(DialogInterface dialog, int i) {
				// 不退出不用执行任何操作
			}
		});
		ad.show();// 显示对话框
	}

方法二：

@Override
	public boolean onKeyDown(int keyCode, KeyEvent event) {
		if (keyCode == KeyEvent.KEYCODE_BACK) {
			exitApplication();
		}
		return true;
	}
private void exitApplication() {
		Builder builder = new Builder(this);
		builder.setIcon(R.drawable.ic_launcher);
		builder.setTitle("退出");
		builder.setMessage("确定退出吗？");
		builder.setPositiveButton("确定", new DialogInterface.OnClickListener() {

			public void onClick(DialogInterface dialog, int which) {
				System.exit(0);

			}
		});
		builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {

			public void onClick(DialogInterface arg0, int arg1) {

			}
		});
		builder.show();
	}