单击警报对话框上的退出按钮时，将显示MainActivity

Question

onBackPressed显示alertDialog。单击退出按钮时，它显示主要活动。再次按下返回键时，将显示alertDialog，但是这次单击退出按钮将关闭应用程序。我想念什么？

这是OpenExitDialog（）代码。

public void OpenExitDialog()    {

    try {
        com.heyzap.sdk.ads.InterstitialAd.fetch();
        if (com.heyzap.sdk.ads.InterstitialAd.isAvailable()) {
            com.heyzap.sdk.ads.InterstitialAd.display(MainActivity.this);
        } else {
            start_AppAd.loadAd(new AdEventListener() {
                @Override
                public void onReceiveAd(Ad ad) {
                    start_AppAd.showAd(new AdDisplayListener() {
                        @Override
                        public void adHidden(Ad ad) { }
                        @Override
                        public void adDisplayed(Ad ad) { }

                        @Override
                        public void adClicked(Ad arg0) { }
                        @Override
                        public void adNotDisplayed(Ad arg0) { }
                    });
                }
                @Override
                public void onFailedToReceiveAd(Ad ad) {

                }
            });
        }
        try {
            AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
            builder.setTitle("Exit");
            builder.setIcon(R.mipmap.ic_launcher);
            builder.setMessage("Thankyou!")
                    .setCancelable(false)
  }
                    })

                    .setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialogInterface, int i) {
                            dialogInterface.cancel();
                        }
                    })
                    .setPositiveButton("Quit", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialogInterface, int i) {
                            finish();
                        }
                    });
            AlertDialog alert = builder.create();
            alert.show();

        } catch (Exception e) {
            e.printStackTrace();
        }
    } catch (Exception e) {
        e.printStackTrace();
    }
}

Answer 1

尝试一下

    @Override
    public void onBackPressed() {

               AlertDialog alertbox = new AlertDialog.Builder(this)
    .setMessage("Do you want to exit application?")
    .setPositiveButton("Quit", new DialogInterface.OnClickListener() {

        // do something when the button is clicked
        public void onClick(DialogInterface arg0, int arg1) {

            finish();
            //close();


        }
    })
    .setNegativeButton("Cancel", new DialogInterface.OnClickListener() {

        // do something when the button is clicked
        public void onClick(DialogInterface arg0, int arg1) {
                       }
    })
      .show();

 }

希望它有用。

Answer 2

.setPositiveButton("Quit", new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialogInterface, int i) {
                            finish();
                            System.exit(0);  //add this line

                        }
                    });