Android Studio 实现单选对话框

Posted 2022-11-22 言人冰

上效果图

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    >
    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="单选对话框"
        android:textSize="20sp"
        android:layout_marginTop="30dp"
        android:gravity="center"
        android:id="@+id/tv"
        />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="设置字体大小"
        android:id="@+id/btn"
        android:layout_marginTop="20dp"
        android:layout_gravity="center"
        />

</LinearLayout>

MainActivity.java

package com.example.singlechoicedialog;

import androidx.appcompat.app.AppCompatActivity;

import android.app.AlertDialog;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity implements View.OnClickListener
    private AlertDialog dialog;
    private TextView textView;
    private int[] textSizeArr = 10,20,25,30,40;//存储字体大小
    private  String[] fontStyleArr= "小号","默认","中号","大号","超大";//存储样式
    int textSize = 1; //单选列表中默认选择的位置
    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //设置监听
        findViewById(R.id.btn).setOnClickListener(this); //为id为btn的按钮邦定监听
        textView = (TextView) findViewById(R.id.tv);

    

    @Override
    public void onClick(View view) 
        //  创建对话框并设置其样式(这里采用链式方程)
        AlertDialog.Builder builder = new AlertDialog.Builder(this)//设置单选框列表
                .setTitle("设置字体的大小")   //设置标题
                .setIcon(R.drawable.bdd) //设置图标
                .setSingleChoiceItems(fontStyleArr, textSize, new DialogInterface.OnClickListener() 
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) 
                        textSize=i; //在OnClick方法中得到被点击的序号 i
                    
                )
                .setPositiveButton("确定", new DialogInterface.OnClickListener() //在对话框中设置“确定”按钮
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) 
                        //为TextView设置在单选对话框中选择的字体大小
                        textView.setTextSize(textSizeArr[textSize]);
                        //设置好字体大小后关闭单选对话框
                        dialog.dismiss();
                    
                )
                .setNegativeButton("取消", new DialogInterface.OnClickListener() //在对话框中设置”取消按钮“
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) 
                        dialog.dismiss();
                    
                );
        dialog = builder.create();
        dialog.show();