项目中有用到抽奖转盘，网上找的demo有些不合设计的要求（不能随意添加转盘中item的个数，不能以上层view滚动等），于是自己尝试写了个自定义的抽奖转盘，方便以在别的项目中更改使用，大致的效果如下图：
这是为点击抽奖之前的效果
整体的思路是下边是一个可以任意添加item的自定义的view，上部份是一张图片，点击图片的时候让图片开始Rotate动画效果，转动到特定的item那里
1.自定义view：
Turnplate
package com.example.hp.loading;import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.Path;import android.graphics.RectF;import android.graphics.Typeface;import android.os.Build;import android.util.AttributeSet;import android.util.Log;import android.view.View;import android.view.WindowManager;import java.util.ArrayList;import java.util.List;/** * Created by hp on /9/5. * 转盘 */public class Turnplate extends View{private Context context;private final float StrarLocation=270;private Paint paint;private float mRadios;//绘制的角度 private List<String> listText;//显示的文字 private List<Float>listRadios;//每个特定弧度的中心位置 private int mCount;//绘制的次数 private List<Integer>listColor;//每个弧度的颜色(最大数目10个) public Turnplate(Context context, AttributeSet attrs) {super(context, attrs);this.context=context;//此构造方法会在xml生成时调用，而不是在Activity使用中调用paint=new Paint();paint.setAntiAlias(true);Path path=new Path();//初始化路径pathlistText=new ArrayList<>();listRadios=new ArrayList<>();listColor=new ArrayList<>();//测试用的颜色，方便给每个item添加不同颜色listColor.add(0xFF0b87f4);//色值不能在此引用xml中的数据，否则不起效果，必须以16进制形式添加listColor.add(0xFFc316de);listColor.add(0xFFcbce25);listColor.add(0xFFf47378);listColor.add(0xFF18dfd8);listColor.add(0xFF7d1ed1);listColor.add(0xFFe6a1ef);listColor.add(0xFFfdd700);listColor.add(0xfba0ec25);}public Turnplate(Context context) {super(context);}@Override protected void onDraw(Canvas canvas) {super.onDraw(canvas);if (listText!=null&&listText.size()>0){//初始化绘制文字的画笔Paint mTextPaint=new Paint();mTextPaint.setColor(Color.WHITE);mTextPaint.setAntiAlias(true);mTextPaint.setDither(true);if(Build.VERSION.SDK_INT>20){mTextPaint.setLetterSpacing(0.1f);}mTextPaint.setTextAlign(Paint.Align.CENTER);mTextPaint.setTextSize(getResources().getDimension(R.dimen.texSize_A)); Typeface typeface=Typeface.create(Typeface.MONOSPACE , Typeface.NORMAL);mTextPaint.setTypeface(typeface);float startRadios=270-mRadios/2;RectF rectF=new RectF(0,0,canvas.getWidth(),canvas.getHeight());for (int i=0;i<listText.size();i++){if (i<listColor.size()-1){paint.setColor(listColor.get(i));}else {paint.setColor(Color.WHITE);}Path path=new Path();path.addArc(rectF, startRadios, mRadios);float textWidth = mTextPaint.measureText(listText.get(i));Paint.FontMetrics metrics=mTextPaint.getFontMetrics();float assent=metrics.ascent;float descent=metrics.descent;float height=(descent-assent);canvas.drawArc(rectF, startRadios, mRadios, true, paint);canvas.drawTextOnPath(listText.get(i),path,0,height,mTextPaint);startRadios+=mRadios;}//测试用 if (listRadios!=null&&listRadios.size()>0){for (int i=0;i<listRadios.size();i++){Log.i("listRadios--i--"+i,"==="+listRadios.get(i));}} }}@Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {//view的宽高度相等，大小为屏幕宽度的3/4WindowManager manager= (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);int width=manager.getDefaultDisplay().getWidth();width-=width/4;setMeasuredDimension(width, width);}/* * 设置显示的文字 * */ public void setText(String[] text){try {mCount=text.length;if (mCount<1){mCount=1;}for (int i=0;i<text.length;i++){listText.add(text[i]);}mRadios=360.0f/mCount;//每个item所占的弧度Log.i("mRadios===",""+mRadios);Log.i("mCount===",""+mCount);//-------------------- for (int i=0;i<listText.size();i++) {float start = 270 + mRadios * i;if (start < 360) {listRadios.add(start);} else {listRadios.add(start - 360);}}invalidate();}catch (Exception e){Log.e("Turnplate-setText-","传入的字符串数组为空，请确认");}}/* * 获取每个环的弧度 * */ public float getMyRadios(){return mRadios;}public float getStartRadios(){//获取开始的角度 return StrarLocation;}//获取所有选项中心位置的弧度数目 public List<Float>getRadioList(){return listRadios;}}
2.xml中引用自定义的view
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="/apk/res/android" xmlns:tools="/tools" android:layout_width="match_parent" android:layout_height="match_parent" tools:context="com.example.hp.loading.MainActivity"><FrameLayout android:layout_width="match_parent" android:layout_height="match_parent"><com.example.hp.loading.Turnplate android:background="#aaeeaa" android:id="@+id/turnplate" android:layout_gravity="center" android:layout_width="100dp" android:layout_height="100dp" /><ImageView android:id="@+id/image" android:clickable="true" android:onClick="rotate" android:src="@mipmap/choujiang" android:layout_gravity="center" android:layout_width="wrap_content" android:layout_height="wrap_content" /></FrameLayout></RelativeLayout>
3.Activity中初始化view并给转盘中的view添加数据源
package com.example.hp.loading;import android.support.v7.app.AppCompatActivity;import android.os.Bundle;import android.util.Log;import android.view.View;import android.view.animation.Animation;import android.view.animation.RotateAnimation;import android.widget.ImageView;import android.widget.Toast;import java.util.ArrayList;import java.util.List;import java.util.Random;public class MainActivity extends AppCompatActivity {private Turnplate turnplate;private ImageView image;private RotateAnimation anim;private float rot;private ImageView imageA;private Float StartRadios;//转盘起始的位置 private int CurrentRadiosId;//转盘当前所处的位置 private List<Float> listRadios;private List<Float>listImaRadios;private int round;//用于产生随机数 private String[]text={"谢谢抽奖","中奖1元","中奖2元","中奖5元","中奖10元","中奖50元","中奖100元"};// @Override protected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);turnplate= (Turnplate) findViewById(R.id.turnplate);image= (ImageView) findViewById(R.id.image);// imageA= (ImageView) findViewById(R.id.imageA); round=text.length;turnplate.setText(text);StartRadios=turnplate.getStartRadios();CurrentRadiosId=0;listRadios=new ArrayList<>();listRadios=turnplate.getRadioList();listImaRadios=new ArrayList<>();for (int i=0;i<listRadios.size();i++){float rado=listRadios.get(i)-270;if (rado>0|rado==0){listImaRadios.add(rado);}else {listImaRadios.add(360+rado);}Log.i("---------listImag",""+listImaRadios.get(i));}}@Override protected void onStart() {super.onStart();}/* * 转动的view * */ public void rotate(View view) {//产生0-round之间的随机数 image.setClickable(false);int sc=new Random().nextInt(round);// Log.i("产生的随机数---"+sc,"item的总数目--"+round); Log.i("当前item的id===" + CurrentRadiosId, "结束的item的id==" + sc);rotateTo(CurrentRadiosId, sc);//从当前的id旋转到sc CurrentRadiosId=sc;//记录新的当前id }private void rotateTo(int currentId, int rotateId) {float curRadio=listRadios.get(currentId);//当前的item的弧度 float rotaRadio=listRadios.get(rotateId);//结束的item的弧度// if (curRadio-rotaRadio>0){// rot=360-curRadio+rotaRadio;// }// else if (curRadio-rotaRadio==0){// rot=0;// }// else {// rot=rotaRadio-curRadio;// } float rotateRadio=360*4+listImaRadios.get(rotateId);//总的旋转度数// Log.i("开始转动的弧度-qq====" + listImaRadios.get(currentId), "转动的弧度====" + rot);// Log.i("开始转动的item位置"+currentId,"结束时的item位置"+rotateId); anim=new RotateAnimation(listImaRadios.get(currentId),rotateRadio,Animation.RELATIVE_TO_SELF,0.5f,Animation.RELATIVE_TO_SELF,0.5f);anim.setDuration(1000);anim.setFillAfter(true);anim.setAnimationListener(new Animation.AnimationListener() {@Override public void onAnimationStart(Animation animation) {}@Override public void onAnimationEnd(Animation animation) {image.setClickable(true);Toast.makeText(MainActivity.this,""+text[CurrentRadiosId],Toast.LENGTH_SHORT).show();//Log.i("转动结束后的当前item===", "" + CurrentRadiosId);Log.i("----------","---------------------------------------------");}@Override public void onAnimationRepeat(Animation animation) {}});image.startAnimation(anim);}}
