Question

我用2个按钮创建了一个APK。退出按钮（按此按钮时，如果没有退出则显示对话框）和按钮转到下一个活动。如果我启动apk并按exit，那么是的，apk可以顺利关闭但是当我按下按钮进入下一个活动，然后返回并按下退出按钮然后会看到对话框，但是当我按YES时，应用程序进入下一个活动，并且不退出apk。

package com.example.myapplication;

import android.content.DialogInterface;
import android.content.Intent;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }

    public void btn133(View v) {
   //Next activity BTN
    Intent intent = new Intent(MainActivity.this, act22.class);
    startActivity(intent);
    }

    @Override
    //Back exit dialog
    public void onBackPressed() {

        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
        builder.setTitle(R.string.app_name);
        builder.setIcon(R.mipmap.ic_launcher);
        builder.setMessage("Do you want to exit?")
                .setCancelable(false)
                .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        finish();
                    }
                })
                .setNegativeButton("No", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.cancel();
                    }
                });
        AlertDialog alert = builder.create();
        alert.show();

    }
    //Exit botun
    public void bt(View v) {
        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
        builder.setTitle(R.string.app_name);
        builder.setIcon(R.mipmap.ic_launcher);
        builder.setMessage("Do you want to exit?")
                .setCancelable(false)
                .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        finish();
                    }
                })
                .setNegativeButton("No", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.cancel();
                    }
                });
        AlertDialog alert = builder.create();
        alert.show();
    }
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">


    <Button
        android:id="@+id/button"
        android:layout_width="326dp"
        android:layout_height="-50dp"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginLeft="55dp"
        android:layout_marginTop="426dp"
        android:onClick="btn133"
        android:text="btn133"

         />

    <Button

        android:layout_width="326dp"
        android:layout_height="-50dp"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginLeft="55dp"
        android:layout_marginTop="508dp"
        android:onClick="bt"
        android:text="exit" />
</RelativeLayout>

Answer 1

enter image description here以此替换您的代码

 @Override
    //Back exit dialog
    public void onBackPressed() {

        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
        builder.setTitle(R.string.app_name);
        builder.setIcon(R.mipmap.ic_launcher);
        builder.setMessage("Do you want to exit?")
                .setCancelable(false)
                .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.cancel();
                        finish();
                    }
                })
                .setNegativeButton("No", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.cancel();
                    }
                });
        AlertDialog alert = builder.create();
        alert.show();

    }
    //Exit botun
    public void bt(View v) {
        AlertDialog.Builder builder = new AlertDialog.Builder(MainActivity.this);
        builder.setTitle(R.string.app_name);
        builder.setIcon(R.mipmap.ic_launcher);
        builder.setMessage("Do you want to exit?")
                .setCancelable(false)
                .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.cancel();
                        finish();
                    }
                })
                .setNegativeButton("No", new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        dialog.cancel();
                    }
                });
        AlertDialog alert = builder.create();
        alert.show();
    }

当我转到下一个活动时，退出对话框不起作用

1 个答案: