xml文件内容：
<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" tools:context=".MainActivity"> <TextView android:id="@+id/tv_target" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="小样把进度条拖到：100" /> <SeekBar android:id="@+id/sb_bulsseye" android:layout_width="match_parent" android:layout_height="wrap_content" android:max="100" android:progress="0"/> <Button android:id="@+id/btn_help" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="帮助" /> <Button android:id="@+id/btn_ok" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="搞定" /> <Button android:id="@+id/btn_replay" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="重新开始" /> <TextView android:id="@+id/tv_source" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="分数：0" /> <TextView android:id="@+id/tv_index" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="局数：1" /></LinearLayout>activity文件内容：
package com.example.helloworld;import androidx.appcompat.app.AlertDialog;import androidx.appcompat.app.AppCompatActivity;import androidx.appcompat.widget.TintContextWrapper;import android.content.Context;import android.content.DialogInterface;import android.os.Bundle;import android.view.View;import android.widget.Button;import android.widget.SeekBar;import android.widget.TextView;import java.util.Random;public class MainActivity extends AppCompatActivity { //属性 TextView tvTarget; TextView tvSource; TextView tvIndex; SeekBar sbBulsseys; Button btnOk; Button btnReplay; Button btnHelp; int randomSource; int finalSource = 0; int index = 1; Context mContext; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); mContext = this; //一般初始化都会独立成一个方法 findView(); randomOfSource(); setListener(); } private void setListener() { //为事件源设置监听 btnOk.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //点击就会调用这个方法 //算分数 index++; int currentSource = sbBulsseys.getProgress(); int source = 100 - Math.abs(currentSource-randomSource); finalSource = source + finalSource; setViewText(); //按钮点击后就会重新出题 randomOfSource(); } }); btnReplay.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { //重新生成随机数 randomOfSource(); finalSource = 0; index = 1; setViewText(); } }); btnHelp.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { AlertDialog.Builder builder = new AlertDialog.Builder(mContext); builder.setTitle("Help") .setMessage("这是帮助") .setPositiveButton("确认", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int which) { dialog.dismiss(); } }); AlertDialog dialog = builder.create(); dialog.show(); } }); } //因为定义为属性了，不需要传参 private void setViewText(){ tvSource.setText("分数："+finalSource); tvIndex.setText("局数："+index); sbBulsseys.setProgress(0); } private void randomOfSource() { Random random = new Random(); randomSource = random.nextInt(99) + 1; tvTarget.setText("小样将进度条拖到：" + randomSource); } private void findView() { tvTarget = (TextView)this.findViewById(R.id.tv_target); tvIndex = (TextView)this.findViewById(R.id.tv_index); tvSource = (TextView)this.findViewById(R.id.tv_source); sbBulsseys = (SeekBar)this.findViewById(R.id.sb_bulsseye); btnHelp = (Button)this.findViewById(R.id.btn_help); btnOk = (Button)this.findViewById(R.id.btn_ok); btnReplay = (Button)this.findViewById(R.id.btn_replay); }}
