准备

IDE：

Android Studio 4.1.1
Build #AI-201.8743.12.41.6953283, built on November 5, 2020
Runtime version: 1.8.0_242-release-1644-b01 amd64
VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o
Windows 10 10.0

Android Virtual Devices：

Name: Pixel_2_API_28
CPU/ABI: Google Play Intel Atom (x86)
Path: C:\Users\86188\.android\avd\Pixel_2_API_28.avd
Target: google_apis_playstore [Google Play] (API level 28)
Skin: pixel_2
SD Card: 512M
fastboot.chosenSnapshotFile: 
runtime.network.speed: full
hw.accelerometer: yes
hw.device.name: pixel_2
hw.lcd.width: 1080
hw.initialOrientation: Portrait
image.androidVersion.api: 28
tag.id: google_apis_playstore
hw.mainKeys: no
hw.camera.front: emulated
avd.ini.displayname: Pixel 2 API 28
hw.gpu.mode: auto
hw.ramSize: 1536
PlayStore.enabled: true
fastboot.forceColdBoot: no
hw.cpu.ncore: 4
hw.keyboard: yes
hw.sensors.proximity: yes
hw.dPad: no
hw.lcd.height: 1920
vm.heapSize: 256
skin.dynamic: yes
hw.device.manufacturer: Google
hw.gps: yes
hw.audioInput: yes
image.sysdir.1: system-images\android-28\google_apis_playstore\x86\
showDeviceFrame: yes
hw.camera.back: virtualscene
AvdId: Pixel_2_API_28
hw.lcd.density: 420
hw.arc: false
hw.device.hash2: MD5:55acbc835978f326788ed66a5cd4c9a7
fastboot.forceChosenSnapshotBoot: no
fastboot.forceFastBoot: yes
hw.trackBall: no
hw.battery: yes
hw.sdCard: yes
tag.display: Google Play
runtime.network.latency: none
disk.dataPartition.size: 6442450944
hw.sensors.orientation: yes
avd.ini.encoding: UTF-8
hw.gpu.enabled: yes

注意：以下示例仅在安卓虚拟设备上运行测试，并没有在真实的设备上运行测试。

项目

简单的对话框

新建项目，选择 Empty Activity，在配置项目时，我选择的 Minimum SDK 是 API 16: Android 4.1 (Jelly Bean)

编辑 src\main\res\layout\activity_main.xml 文件，删除原有的 TextView 元素，新增 Button 元素：

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

    <Button
        android:id="@+id/button"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:layout_marginLeft="16dp"
        android:layout_marginTop="16dp"
        android:layout_marginEnd="16dp"
        android:layout_marginRight="16dp"
        android:text="Open Alert Dialog"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

编辑 MainActivity 文件，关于 AlertDialog 的代码在第 34 ~ 58 行：

package com.mk;

import androidx.appcompat.app.AppCompatActivity;

import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {
      
      

    private Context context;
    private Button button = null;

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

        context = this;
        initView();
    }

    private void initView() {
      
      
        button = (Button) findViewById(R.id.button);

        button.setOnClickListener(new View.OnClickListener() {
      
      

            @Override
            public void onClick(View v) {
      
      
                AlertDialog.Builder builder = new AlertDialog.Builder(context);
                AlertDialog alertDialog = builder
                        .setTitle("提示")
                        .setMessage("普通对话框")
                        .setNeutralButton("中立", new DialogInterface.OnClickListener() {
      
      
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
      
      
                                Toast.makeText(context, "中立按钮", Toast.LENGTH_SHORT).show();
                            }
                        })
                        .setNegativeButton("否定", new DialogInterface.OnClickListener() {
      
      
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
      
      
                                Toast.makeText(context, "否定按钮", Toast.LENGTH_SHORT).show();
                            }
                        })
                        .setPositiveButton("确定", new DialogInterface.OnClickListener() {
      
      
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
      
      
                                Toast.makeText(context, "确定按钮", Toast.LENGTH_SHORT).show();
                            }
                        })
                        .create();

                alertDialog.show();
            }
        });
    }
}

运行效果：

简单列表对话框

修改第 1 例中的 MainActivity 文件中的第 34 ~ 58 行，使用以下代码替换：

final String[] lesson = {
      
       "语文", "数学", "英语", "化学", "生物", "物理", "历史", "地理", "政治", "体育" };

AlertDialog.Builder builder = new AlertDialog.Builder(context);
AlertDialog alertDialog = builder
        .setTitle("高中课程")
        .setItems(lesson, new DialogInterface.OnClickListener() {
      
      
            @Override
            public void onClick(DialogInterface dialog, int which) {
      
      
                Toast.makeText(context, "你选择了" + lesson[which], Toast.LENGTH_SHORT).show();
            }
        })
        .create();

alertDialog.show();

运行效果：

单选列表对话框

修改第 1 例中的 MainActivity 文件中的第 34 ~ 58 行，使用以下代码替换：

final String[] lesson = {
      
       "语文", "数学", "英语", "化学", "生物", "物理", "历史", "地理", "政治", "体育" };

AlertDialog.Builder builder = new AlertDialog.Builder(context);
AlertDialog alertDialog = builder
        .setTitle("高中课程")
        .setSingleChoiceItems(lesson, 0, new DialogInterface.OnClickListener() {
      
      
            @Override
            public void onClick(DialogInterface dialog, int which) {
      
      
                Toast.makeText(context, "你选择了" + lesson[which], Toast.LENGTH_SHORT).show();
            }
        })
        .setNegativeButton("否定", new DialogInterface.OnClickListener() {
      
      
            @Override
            public void onClick(DialogInterface dialog, int which) {
      
      
                Toast.makeText(context, "否定按钮", Toast.LENGTH_SHORT).show();
            }
        })
        .setPositiveButton("确定", new DialogInterface.OnClickListener() {
      
      
            @Override
            public void onClick(DialogInterface dialog, int which) {
      
      
                Toast.makeText(context, "确定按钮", Toast.LENGTH_SHORT).show();
            }
        })
        .create();

alertDialog.show();

运行效果：

多选列表对话框

修改第 1 例中的 MainActivity 文件中的第 34 ~ 58 行，使用以下代码替换：

final String[] lesson = {
      
       "语文", "数学", "英语", "化学", "生物", "物理", "历史", "地理", "政治", "体育" };
boolean[] checkedItems = {
      
       true, true, true, false, false, false, false, false, false, true }; // 默认选择

AlertDialog.Builder builder = new AlertDialog.Builder(context);
AlertDialog alertDialog = builder
        .setTitle("高中课程")
        .setMultiChoiceItems(lesson, checkedItems, new DialogInterface.OnMultiChoiceClickListener() {
      
      
            @Override
            public void onClick(DialogInterface dialog, int which, boolean isChecked) {
      
      
                checkedItems[which] = isChecked;
            }
        })
        .setNegativeButton("否定", new DialogInterface.OnClickListener() {
      
      
            @Override
            public void onClick(DialogInterface dialog, int which) {
      
      
                Toast.makeText(context, "否定按钮", Toast.LENGTH_SHORT).show();
            }
        })
        .setPositiveButton("确定", new DialogInterface.OnClickListener() {
      
      
            @Override
            public void onClick(DialogInterface dialog, int which) {
      
      
                StringBuilder results = new StringBuilder();
                for (int i = 0; i < checkedItems.length; i++) {
      
      
                    if (checkedItems[i]) {
      
      
                        results.append(lesson[i]).append(" ");
                    }
                }
                Toast.makeText(context, "你选择：" + results.toString(), Toast.LENGTH_SHORT).show();
            }
        })
        .create();

alertDialog.show();

运行效果：

自定义标题和修改确定按钮外边距

修改第 1 例中的 MainActivity 文件中的第 34 ~ 58 行，使用以下代码替换：

第 2 ~ 7 行：自定义标题样式
第 12 行：设置自定义标题
第 31 ~ 34 行：修改确定（Positive Button）按钮的左边距

// 自定义标题样式
TextView title = new TextView(context);
title.setText("提示");
title.setPadding(10, 30, 10, 10);
title.setGravity(Gravity.CENTER); // 居中
title.setTextSize(18);
title.setTextColor(Color.BLACK);

// 简单的对话框
AlertDialog.Builder builder = new AlertDialog.Builder(context);
AlertDialog alertDialog = builder
        .setCustomTitle(title) // 设置自定义标题
        .setMessage("自定义标题和修改确定按钮外边距")
        .setNegativeButton("否定", new DialogInterface.OnClickListener() {
      
      
            @Override
            public void onClick(DialogInterface dialog, int which) {
      
      
                Toast.makeText(context, "否定按钮", Toast.LENGTH_SHORT).show();
            }
        })
        .setPositiveButton("确定", new DialogInterface.OnClickListener() {
      
      
            @Override
            public void onClick(DialogInterface dialog, int which) {
      
      
                Toast.makeText(context, "确定按钮", Toast.LENGTH_SHORT).show();
            }
        })
        .create();

alertDialog.show();

// 修改确定按钮的左边距
Button buttonPositive = alertDialog.getButton(AlertDialog.BUTTON_POSITIVE);
LinearLayout.LayoutParams layoutParams = (LinearLayout.LayoutParams) buttonPositive.getLayoutParams();
layoutParams.setMargins(layoutParams.leftMargin + 20, layoutParams.topMargin, layoutParams.rightMargin, layoutParams.bottomMargin); // 外边距
buttonPositive.setLayoutParams(layoutParams);

运行效果：

参考

AlertDialog(对话框)详解

Android修改原生AlertDialog按钮的颜色大小边距位置以及标题居中等

Android -AlertDialog 对话框

文章目录

准备

项目

简单的对话框

简单列表对话框

单选列表对话框

多选列表对话框

自定义标题和修改确定按钮外边距

参考

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