后退按钮，最后一次活动 [英] Back button and last activity

问题描述

我的应用程序链的一些活动。

My app chains some activities.

如果您preSS后退按钮，你回去翻阅旧的活动，那么你突然退出应用程序！

if you press the back button, you go back through old activities then you suddenly quit the application !

所以我需要显示一个消息，如你真的想退出，如果它是在堆栈中的最后一项活动

so I need to show a message like "do you really want to exit" if it's the last activity on stack

我知道如何重写后退按钮，但我不明白怎么知道有多少活动是历史

I know how to override the back button but i can't figure how to know how many activity are in history

@Override
public boolean onKeyDown(int keyCode, KeyEvent event)  {
    if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {
        // Is it the last activity on stack ? 
        // so show confirm dialog
        return true;
    }

    return super.onKeyDown(keyCode, event);
}

请帮忙。

推荐答案

就可以实现，使用结束（）函数

you can achieve that using the finish() function

public void finish() {
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setMessage("do you really want to exit?");
        builder.setCancelable(false);
        builder.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int id) {
                quit();
            }
        });
        builder.setNegativeButton("No", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int id) {
                dialog.cancel();
            }
        });
        AlertDialog alert = builder.create();
        alert.show();
    }

    public void quit() {
        super.finish();
    };

这篇关于后退按钮，最后一次活动的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！