Java onBackpressed（）中的问题

实际上，我的问题是当我按下后退按钮时，它会显示一个对话框，同时应用程序也会在没有对键进行任何操作的情况下完成？谁能解决这个问题

@Override
public void onBackPressed() {
    super.onBackPressed();
    AlertDialog.Builder ab = new AlertDialog.Builder(this);
    ab.setMessage("Really want to exit");
    ab.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            finish();
        }
    });
    ab.setNegativeButton("No", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            Main.super.onBackPressed();
        }
    });
    ab.create();
    ab.show();
}

拆下超级按钮，然后反压；从方法中，仅将其保留在onClick中

似乎您正在两个按钮中执行相同的操作，您应该从negativeButton中删除Main.super.on Backpressed

拆下超级按钮，然后反压；从方法中，仅将其保留在onClick中

似乎您正在两个按钮中执行相同的操作，您应该从negativeButton中删除Main.super.on Backpressed

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不要调用onBackPressed的超级方法

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不要调用onBackPressed的超级方法

您需要删除，super.on backpressed；从上往下压。那么你的功能应该是

@Override
public void onBackPressed() {

AlertDialog.Builder ab = new AlertDialog.Builder(this);
ab.setMessage("Really want to exit");
ab.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {
        finish();
    }
});
ab.setNegativeButton("No", new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {
        Main.super.onBackPressed();
    }
});
ab.create();
ab.show();
}

您需要删除，super.on backpressed；从上往下压。那么你的功能应该是

@Override
public void onBackPressed() {

AlertDialog.Builder ab = new AlertDialog.Builder(this);
ab.setMessage("Really want to exit");
ab.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {
        finish();
    }
});
ab.setNegativeButton("No", new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {
        Main.super.onBackPressed();
    }
});
ab.create();
ab.show();
}

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如果我按“否”，应用程序也将关闭如果我按，如何限制该活动no@A.asha检查我的最新答案。卸下此Main.super.on后压；如果我按“否”，应用程序也将关闭如果我按，如何限制该活动no@A.asha检查我的最新答案。卸下此Main.super.on后压；

@Override
public void onBackPressed() {

    AlertDialog.Builder ab = new AlertDialog.Builder(this);
    ab.setMessage("Really want to exit");
    ab.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            finish();
        }
    });
    ab.setNegativeButton("No", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {

        }
    });
    ab.create();
    ab.show();
}

try this
  @Override
    public void onBackPressed() {

        AlertDialog.Builder ab = new AlertDialog.Builder(this);
        ab.setMessage("Really want to exit");
        ab.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
               finish();
            }
        });
        ab.setNegativeButton("No", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {
                Main.super.onBackPressed();
            }
        });
        ab.create();
        ab.show();
    }

@Override
public void onBackPressed() {

AlertDialog.Builder ab = new AlertDialog.Builder(this);
ab.setMessage("Really want to exit");
ab.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {
        finish();
    }
});
ab.setNegativeButton("No", new DialogInterface.OnClickListener() {
    @Override
    public void onClick(DialogInterface dialog, int which) {
        Main.super.onBackPressed();
    }
});
ab.create();
ab.show();
}