Android自定义View实现QQ音乐中圆形旋转碟子

qq音乐中圆形旋转碟子

思路分析：
1、在onmeasure中测量整个view的宽和高后，设置宽高
2、获取我们res的图片资源后，在ondraw方法中进行绘制圆形图片
3、通过handler发送runnable来启动旋转线程（如果只想做圆形头像的话，这步可以去掉）
4、在布局中使用我们的view

效果图：

贴出我们的变量信息：

//view的宽和高 
int mheight = 0; 
int mwidth = 0; 
//圆形图片 
bitmap bitmap = null; 
//圆形图片的真实半径 
int radius = 0; 
//旋转动画的矩形 
matrix matrix = new matrix(); 
//旋转动画的角度 
int degrees = 0; 

步骤一：测量整个view的宽和高后，设置宽高

@override 
protected void onmeasure(int widthmeasurespec, int heightmeasurespec) { 
 super.onmeasure(widthmeasurespec, heightmeasurespec); 
 //测量整个view的宽和高 
 mwidth = measuredwidth(widthmeasurespec); 
 mheight= measuredheight(heightmeasurespec); 
 setmeasureddimension(mwidth, mheight); 
} 
 
private int measuredwidth(int widthmeasurespec) { 
 int mode = measurespec.getmode(widthmeasurespec); 
 int size = measurespec.getsize(widthmeasurespec); 
 if (mode == measurespec.exactly) { 
  mwidth = size; 
 } else { 
  //由图片决定宽度 
  int value = getpaddingleft() + getpaddingright() + bitmap.getwidth(); 
  if (mode == measurespec.at_most) { 
   //由图片和padding决定宽度，但是不能超过view的宽 
   mwidth = math.min(value, size); 
  } 
 } 
 return mwidth; 
} 
 
private int measuredheight(int heightmeasurespec) { 
 int mode = measurespec.getmode(heightmeasurespec); 
 int size = measurespec.getsize(heightmeasurespec); 
 if (mode == measurespec.exactly) { 
  mheight = size; 
 } else { 
  //由图片决定高度 
  int value = getpaddingtop() + getpaddingbottom() + bitmap.getheight(); 
  if (mode == measurespec.at_most) { 
   //由图片和padding决定高度，但是不能超过view的高 
   mheight = math.min(value, size); 
  } 
 } 
 return mheight; 
} 

步骤二：获取我们res的图片资源后，在ondraw方法中进行绘制圆形图片

//获取res的图片资源 
bitmap = bitmapfactory.decoderesource(getresources(), r.drawable.icon); 
@override 
protected void ondraw(canvas canvas) { 
 super.ondraw(canvas); 
 canvas.concat(matrix); 
 //真实的半径必须是view的宽高最小值 
 radius = math.min(mwidth, mheight); 
 //如果图片本身宽高太大，进行相应的缩放 
 bitmap = bitmap.createscaledbitmap(bitmap, radius, radius, false); 
 //画圆形图片 
 canvas.drawbitmap(createcircleimage(bitmap, radius), 0, 0, null); 
 matrix.reset(); 
} 
 
private bitmap createcircleimage(bitmap source, int radius) { 
 paint paint = new paint(); 
 paint.setantialias(true); 
 bitmap target = bitmap.createbitmap(radius, radius, bitmap.config.argb_8888); 
 //产生一个同样大小的画布 
 canvas canvas = new canvas(target); 
 //首先绘制圆形 
 canvas.drawcircle(radius / 2, radius / 2, radius / 2, paint); 
 //使用src_in模式显示后画图的交集处 
 paint.setxfermode(new porterduffxfermode(porterduff.mode.src_in)); 
 //绘制图片，从（0，0）画 
 canvas.drawbitmap(source, 0, 0, paint); 
 return target; 
} 

步骤三：通过handler发送runnable来启动旋转线程

//开始旋转 
mhandler.post(runnable); 
[java] view plain copy 在code上查看代码片派生到我的代码片
//-----------旋转动画----------- 
handler mhandler = new handler(); 
runnable runnable = new runnable() { 
 @override 
 public void run() { 
  matrix.postrotate(degrees++, radius / 2, radius / 2); 
  //重绘 
  invalidate(); 
  mhandler.postdelayed(runnable, 50); 
 } 
}; 

步骤四：在布局中使用我们的view

<com.handsome.cycle.mycycleview 
 android:layout_width="wrap_content" 
 android:layout_height="wrap_content" /> 

下面是整个类的源码

public class mycycleview extends view { 
 
 //view的宽和高 
 int mheight = 0; 
 int mwidth = 0; 
 //圆形图片 
 bitmap bitmap = null; 
 //圆形图片的真实半径 
 int radius = 0; 
 //旋转动画的矩形 
 matrix matrix = new matrix(); 
 //旋转动画的角度 
 int degrees = 0; 
 
 //-----------旋转动画----------- 
 handler mhandler = new handler(); 
 runnable runnable = new runnable() { 
  @override 
  public void run() { 
   matrix.postrotate(degrees++, radius / 2, radius / 2); 
   //重绘 
   invalidate(); 
   mhandler.postdelayed(runnable, 50); 
  } 
 }; 
 
 public mycycleview(context context) { 
  super(context); 
  initview(); 
 } 
 
 public mycycleview(context context, attributeset attrs) { 
  super(context, attrs); 
  initview(); 
 } 
 
 public mycycleview(context context, attributeset attrs, int defstyleattr) { 
  super(context, attrs, defstyleattr); 
  initview(); 
 } 
 
 public void initview() { 
  //获取res的图片资源 
  bitmap = bitmapfactory.decoderesource(getresources(), r.drawable.icon); 
  //开始旋转 
  mhandler.post(runnable); 
 } 
 
 @override 
 protected void onmeasure(int widthmeasurespec, int heightmeasurespec) { 
  super.onmeasure(widthmeasurespec, heightmeasurespec); 
  //测量整个view的宽和高 
  mwidth = measuredwidth(widthmeasurespec); 
  mheight = measuredheight(heightmeasurespec); 
  setmeasureddimension(mwidth, mheight); 
 } 
 
 private int measuredwidth(int widthmeasurespec) { 
  int mode = measurespec.getmode(widthmeasurespec); 
  int size = measurespec.getsize(widthmeasurespec); 
  if (mode == measurespec.exactly) { 
   mwidth = size; 
  } else { 
   //由图片决定宽度 
   int value = getpaddingleft() + getpaddingright() + bitmap.getwidth(); 
   if (mode == measurespec.at_most) { 
    //由图片和padding决定宽度，但是不能超过view的宽 
    mwidth = math.min(value, size); 
   } 
  } 
  return mwidth; 
 } 
 
 private int measuredheight(int heightmeasurespec) { 
  int mode = measurespec.getmode(heightmeasurespec); 
  int size = measurespec.getsize(heightmeasurespec); 
  if (mode == measurespec.exactly) { 
   mheight = size; 
  } else { 
   //由图片决定高度 
   int value = getpaddingtop() + getpaddingbottom() + bitmap.getheight(); 
   if (mode == measurespec.at_most) { 
    //由图片和padding决定高度，但是不能超过view的高 
    mheight = math.min(value, size); 
   } 
  } 
  return mheight; 
 } 
 
 @override 
 protected void ondraw(canvas canvas) { 
  super.ondraw(canvas); 
  canvas.concat(matrix); 
  //真实的半径必须是view的宽高最小值 
  radius = math.min(mwidth, mheight); 
  //如果图片本身宽高太大，进行相应的缩放 
  bitmap = bitmap.createscaledbitmap(bitmap, radius, radius, false); 
  //画圆形图片 
  canvas.drawbitmap(createcircleimage(bitmap, radius), 0, 0, null); 
  matrix.reset(); 
 } 
 
 private bitmap createcircleimage(bitmap source, int radius) { 
  paint paint = new paint(); 
  paint.setantialias(true); 
  bitmap target = bitmap.createbitmap(radius, radius, bitmap.config.argb_8888); 
  //产生一个同样大小的画布 
  canvas canvas = new canvas(target); 
  //首先绘制圆形 
  canvas.drawcircle(radius / 2, radius / 2, radius / 2, paint); 
  //使用src_in模式显示后画图的交集处 
  paint.setxfermode(new porterduffxfermode(porterduff.mode.src_in)); 
  //绘制图片，从（0，0）画 
  canvas.drawbitmap(source, 0, 0, paint); 
  return target; 
 } 
} 

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。