Android实现抽奖转盘实例代码

本文详述了android抽奖程序的实现方法，程序为一个抽奖大转盘代码，里面定义了很多图形方法和动画。
实现主要功能的SlyderView.java源代码如下：
import android.app.Activity;import android.content.Context;import android.graphics.BlurMaskFilter;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.ColorMatrixColorFilter;import android.graphics.EmbossMaskFilter;import android.graphics.MaskFilter;import android.graphics.Paint;import android.graphics.PorterDuffXfermode;import android.graphics.Paint.Style;import android.graphics.PorterDuff.Mode;import android.graphics.Path;import android.graphics.RadialGradient;import android.graphics.RectF;import android.graphics.Shader.TileMode;import android.util.AttributeSet;import android.util.TypedValue;import android.view.View;public class SlyderView extends View{public SlyderView（Context context, AttributeSet attrs, int defStyleAttr） {super（context, attrs, defStyleAttr）;init（context）;}public SlyderView（Context context, AttributeSet attrs） {super（context, attrs）;init（context）;}public SlyderView（Context context） {super（context）;init（context）;}/** * 屏幕宽度 */private int screenW;/** * 屏幕的高度 */private int screenH;/** * 分割的度数 */private int [] drgrees = {20,50,40,90,70,40,50};/*** * 分割的文字 */private String [] strs = {"level1","level2","level3","level4","level5","level6","level7"};/** * 分割的颜色 */private int [] colos = new int[] { 0xfed9c960, 0xfe57c8c8, 0xfe9fe558, 0xfef6b000, 0xfef46212, 0xfecf2911, 0xfe9d3011 };/** * 画笔 */private Paint paint;/** * 文字的大小 */private float textSize = TypedValue.applyDimension（TypedValue.COMPLEX_UNIT_SP, 15, getResources（）.getDisplayMetrics（））;/** * 文字的颜色 */private int textcolor = Color.WHITE;/** * 园的半径 */private float radius = TypedValue.applyDimension（TypedValue.COMPLEX_UNIT_SP, 100, getResources（）.getDisplayMetrics（））;/** * 画文字的距离 */private float textdis = TypedValue.applyDimension（TypedValue.COMPLEX_UNIT_SP, 80, getResources（）.getDisplayMetrics（））;/** * 画箭头的大小 */private float roketSize = TypedValue.applyDimension（TypedValue.COMPLEX_UNIT_SP, 10, getResources（）.getDisplayMetrics（））;private float initDegress = 0;/** * 圆心 */private float centerX;/** * 圆心 */private float centerY;/** * 立体边缘 */private MaskFilter filter = new EmbossMaskFilter（new float[] { 1, 1, 1 },0.4f, 6, 3.5f）;private MaskFilter outerFilter = new BlurMaskFilter（10, BlurMaskFilter.Blur.OUTER）;private MaskFilter innerFilter = new BlurMaskFilter（10, BlurMaskFilter.Blur.INNER）;@SuppressWarnings（"deprecation"）private void init（Context context）{paint = new Paint（）;paint.setAntiAlias（true）;paint.setStyle（Style.FILL）;paint.setColor（Color.WHITE）;screenW = （（Activity）context）.getWindowManager（）.getDefaultDisplay（）.getWidth（）;screenH = （（Activity）context）.getWindowManager（）.getDefaultDisplay（）.getHeight（）;int[] colores = new int[3];colores[0] = Color.rgb（0xfF, 0x99, 0x00）;colores[1] = Color.rgb（0xff, 0xff, 0x00）;colores[2] = Color.rgb（0xff, 0x99, 0x00）;float[] positions = new float[3];positions[0] = 0.0f;positions[1] = 0.5f;positions[2] = 1.0f;gradient = new RadialGradient（centerX, centerY, radius/5, colores, positions, TileMode.CLAMP）;}/** * 绘制三角箭头 */private Path path = new Path（）;/** * 绘制矩形框 */private RectF oval;/** * 外圆内阴影矩阵 */private ColorMatrixColorFilter colorFilter = new ColorMatrixColorFilter（new float[]{1,0,0,0,0,0,1,0,0,0,0,0,1,0,0,0,0,0,-1,255}）;@Overrideprotected void onDraw（Canvas canvas） {super.onDraw（canvas）;centerX = screenW/2;centerY = screenH/2;oval = new RectF（centerX-radius,centerY-radius,centerX+radius,centerY+radius）;float start = 0;paint.setColor（Color.rgb（0xdd, 0xdd, 0xdd））;paint.setAlpha（127）;canvas.drawCircle（centerX, centerY, radius+10, paint）;paint.setAlpha（255）;//画扇形paint.setAntiAlias（true）;for（int i=0;i<drgrees.length;i++）{float sweepAngle = drgrees[i];float startAngle = start;paint.setColor（colos[i%colos.length]）;canvas.drawArc（oval, startAngle, sweepAngle, true, paint）;start += drgrees[i];}//画文字paint.setColor（textcolor）;paint.setAntiAlias（true）;paint.setTextSize（textSize）;paint.setTextAlign（Paint.Align.RIGHT）;start = 0;for（int i=0;i<drgrees.length;i++）{canvas.save（）;canvas.rotate（start+drgrees[i]/2, centerX, centerY）;canvas.drawText（strs[i], centerX+textdis, centerY, paint）;canvas.restore（）;start += drgrees[i];}int saveCount = canvas.save（）;//画外层立体效果paint.setColorFilter（colorFilter）;canvas.saveLayer（oval,paint,Canvas.ALL_SAVE_FLAG）;paint.setColorFilter（null）;canvas.drawARGB（255, 0, 0, 0）;paint.setXfermode（new PorterDuffXfermode（Mode.CLEAR））;canvas.drawCircle（centerX, centerY, radius, paint）;paint.setXfermode（null）;paint.setMaskFilter（innerFilter）;paint.setColor（Color.argb（0xff, 0, 0, 0））;canvas.drawCircle（centerX, centerY, radius, paint）;paint.setMaskFilter（null）;canvas.restoreToCount（saveCount）;//画内圆和内园效果canvas.save（）;paint.setColor（Color.argb（0xff, 0, 0, 0））;paint.setAntiAlias（true）;paint.setMaskFilter（outerFilter）;canvas.rotate（initDegress, centerX, centerY）;canvas.drawCircle（centerX, centerY, radius/3, paint）;paint.setMaskFilter（null）;paint.setColor（Color.WHITE）;canvas.drawCircle（centerX, centerY, radius/3, paint）;//画三角型叠加当箭头path.moveTo（centerX-radius/3, centerY）;path.lineTo（centerX, centerY-radius/3-roketSize）;path.lineTo（centerX+radius/3, centerY）;path.close（）;canvas.drawPath（path, paint）;canvas.restore（）;paint.setMaskFilter（filter）;paint.setColor（Color.GREEN）;paint.setShader（gradient）;canvas.drawCircle（centerX, centerY, radius/5, paint）;paint.setMaskFilter（null）;paint.setShader（null）;//重绘调整三角的指向达到滚动的效果，现实项目中可不能这样用的，效率太低下了，拆分View用动画完成滚动才是王道if（isRunning）{if（initDegress>=360）{initDegress = 0;}initDegress +=4;invalidate（）;}if（isStoping）{if（initDegress<=360）{initDegress+=4;invalidate（）;}else{if（initDegress-360<stop_degress）{initDegress+=2;invalidate（）;}}}}private boolean isRunning = false;private boolean isStoping = false;private int stop_degress =90;/** * 渐变 */private RadialGradient gradient;public void play（）{isRunning = true;invalidate（）;}public void stop（int count）{for（int i =0;i<=count;i++）{if（i == count）{stop_degress +=drgrees[i]/2;}else{stop_degress +=drgrees[i];}}isStoping = true;isRunning = false;invalidate（）;}}