Android自定义SurfaceView实现抽奖转盘实例源代码

分享一款自定义Surfaceview实现幸运大抽奖的Demo、界面比较简单、代码也不复杂、可以根据自己项目的需求修改界面、下面是Demo的截图

绘制盘块图片代码

private void drawIcon(float tmpAngle, Bitmap bitmap) {
    //设置图片的宽度为直径的1/8
    int imgWidth = mRadius/8;
    
    float angle = (float) ((tmpAngle 360/itemCount/2)*Math.PI/180);
    
    int x = (int) (mCenter mRadius/2/2*Math.cos(angle));
    int y = (int) (mCenter mRadius/2/2*Math.sin(angle));
    
    //确定那个图片的位置
    Rect rect = new Rect(x-imgWidth/2, y-imgWidth/2, x imgWidth/2, y imgWidth/2);
    
    canvas.drawBitmap(bitmap, null, rect,null);
}

绘制文本代码

private void drawText(float tmpAngle, float sweepAngle, String string) {
    Path path = new Path();
    path.addArc(mRange, tmpAngle, sweepAngle);
    
    // 利用水平偏移量让文字居中
    float textWidth =  mTextPanit.measureText(string);
    int hOffset = (int) (mRadius*Math.PI/itemCount/2 - textWidth/2);
    
    //垂直偏移量
    int vOffset = mRadius/2/6;
    
    canvas.drawTextOnPath(string, path, hOffset, vOffset, mTextPanit);
}

点击启动旋转

public void luckyStart(int index){
    //计算每一项的角度
    float angle = 360/itemCount;
    
    //计算每一项中奖范围（当前index）
    //1-->150~210
    //0-->210~270
    float from = 270-(index
             1)*angle;
    float end = from angle;
    
    //设置停下来需要旋转的距离
    float targetFrom = 4*360   from;
    float targetEnd = 4*360   end;
    
    float v1= (float) ((-1 Math.sqrt(1 8*targetFrom))/2);
    float v2= (float) ((-1 Math.sqrt(1 8*targetEnd))/2);
    
    mSpeed = v1 Math.random()*(v2-v1);
    isShouldEnd = false;
}

android抽奖转盘源代码下载链接: android抽奖转盘代码 密码: khwt