java - 抽屉导航上的 Back Pressed Exit 对话框 Back Pressed 不起作用

Question

我想实现抽屉导航后按对话框上的对话框后按。 该对话框有两个按钮，当我单击“确定”时，它会退出应用程序。 问题是对话框没有显示...

这是我的抽屉导航 onBackpressed 代码....

@Override
public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);

    } else {
        super.onBackPressed();
        Toast.makeText(this, "BACK PRESSED", Toast.LENGTH_SHORT).show();
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        builder.setTitle("Choose Option");
        builder.setMessage("Are You Sure To Exit??");
        builder.setPositiveButton("Cancel", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                //go to update activity
                dialog.cancel();

            }
        });
        builder.setNeutralButton("Exit", new DialogInterface.OnClickListener() {
            @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
            @Override
            public void onClick(DialogInterface dialog, int which) {
                //go to Remove Item
                finishAffinity();
                dialog.cancel();

            }
        });

Answer 1

试试这个代码

@Override
    public void onBackPressed() {
    DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);

    } else {
        AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(this);
        alertDialogBuilder.setTitle("Exit Application?");
        alertDialogBuilder
                .setMessage("Click yes to exit!")
                .setCancelable(false)
                .setPositiveButton("Yes",
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog, int id) {
                                moveTaskToBack(true);
                                android.os.Process.killProcess(android.os.Process.myPid());
                                System.exit(1);
                            }
                        })

                .setNegativeButton("No", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {

                        dialog.cancel();
                    }
                });

        AlertDialog alertDialog = alertDialogBuilder.create();
        alertDialog.show();
    }
}