Android自定义ImageView实现图片圆形 ，椭圆和矩形圆角显示

Android中的ImageView只能显示矩形的图片，为了用户体验更多，Android实现圆角矩形，圆形或者椭圆等图形，一般通过自定义ImageView来实现，首先获取到图片的Bitmap，然后通过Paint和onDraw（）进行圆形图片显示。

效果图：

代码：

 /**
  * 实现圆形、圆角，椭圆等自定义图片View。
  * @author zq
  *
  */
 public class  ZQImageViewRoundOval extends ImageView {
 
     private Paint mPaint;
 
     private int mWidth;
 
     private int mHeight;
 
     private int mRadius;//圆半径
 
     private RectF mRect;//矩形凹行大小
 
     private int mRoundRadius;//圆角大小
 
     private BitmapShader mBitmapShader;//图形渲染
 
     private Matrix mMatrix;
 
     private int mType;//记录是圆形还是圆角矩形
 
     public static final int TYPE_CIRCLE = 0;//圆形
     public static final int TYPE_ROUND = 1;//圆角矩形
     public static final int TYPE_OVAL = 2;//椭圆形
     public static final int DEFAUT_ROUND_RADIUS = 10;//默认圆角大小
 
     public ZQImageViewRoundOval(Context context) {
         this(context, null);
         // TODOAuto-generated constructor stub
     }
 
     public ZQImageViewRoundOval(Context context, AttributeSet attrs) {
         this(context,attrs, 0);
         // TODOAuto-generated constructor stub
     }
 
     public ZQImageViewRoundOval(Context context, AttributeSet attrs,int defStyle){
         super(context,attrs, defStyle);
         initView();
     }
 
     private void initView() {
         mPaint = new Paint();
         mPaint.setAntiAlias(true);
         mMatrix = new Matrix();
         mRoundRadius = DEFAUT_ROUND_RADIUS;
     }
 
     @Override
     protected void onMeasure(int widthMeasureSpec,intheightMeasureSpec) {
         // TODOAuto-generated method stub
         super.onMeasure(widthMeasureSpec,heightMeasureSpec);
         // 如果是绘制圆形，则强制宽高大小一致
         if (mType ==TYPE_CIRCLE) {
             mWidth = Math.min(getMeasuredWidth(),getMeasuredHeight());
             mRadius = mWidth / 2;
             setMeasuredDimension(mWidth, mWidth);
         }
 
     }
 
     @Override
     protected void onDraw(Canvas canvas) {
 
         if (null ==getDrawable()) {
             return;
         }
         setBitmapShader();
         if (mType ==TYPE_CIRCLE) {
             canvas.drawCircle(mRadius, mRadius, mRadius, mPaint);
         } else if (mType == TYPE_ROUND) {
             mPaint.setColor(Color.RED);
             canvas.drawRoundRect(mRect, mRoundRadius, mRoundRadius, mPaint);
         }else if(mType == TYPE_OVAL){
             canvas.drawOval(mRect, mPaint);
         }
     }
 
     @Override
     protected void onSizeChanged(int w,int h, int oldw,int oldh) {
         // TODOAuto-generated method stub
         super.onSizeChanged(w,h, oldw, oldh);
         mRect = new RectF(0,0, getWidth(), getHeight());
     }
 
     /**
      * 设置BitmapShader
      */
     private void setBitmapShader() {
         Drawable drawable = getDrawable();
         if (null ==drawable) {
             return;
         }
         Bitmap bitmap = drawableToBitmap(drawable);
         // 将bitmap作为着色器来创建一个BitmapShader
         mBitmapShader = newBitmapShader(bitmap, TileMode.CLAMP, TileMode.CLAMP);
         float scale =1.0f;
         if (mType ==TYPE_CIRCLE) {
             // 拿到bitmap宽或高的小值
             int bSize =Math.min(bitmap.getWidth(), bitmap.getHeight());
             scale = mWidth * 1.0f /bSize;
 
         } else if (mType == TYPE_ROUND ||mType == TYPE_OVAL) {
             // 如果图片的宽或者高与view的宽高不匹配，计算出需要缩放的比例；缩放后的图片的宽高，一定要大于我们view的宽高；所以我们这里取大值；
             scale = Math.max(getWidth() * 1.0f/ bitmap.getWidth(), getHeight() * 1.0f / bitmap.getHeight());
         }
         // shader的变换矩阵，我们这里主要用于放大或者缩小
         mMatrix.setScale(scale,scale);
         // 设置变换矩阵
         mBitmapShader.setLocalMatrix(mMatrix);
         mPaint.setShader(mBitmapShader);
 
     }
 
     /**
      * drawable转bitmap
      *
      * @paramdrawable
      * @return
      */
     private Bitmap drawableToBitmap(Drawable drawable) {
         if (drawableinstanceof BitmapDrawable) {
             BitmapDrawable bitmapDrawable =(BitmapDrawable) drawable;
             returnbitmapDrawable.getBitmap();
         }
         int w =drawable.getIntrinsicWidth();
         int h =drawable.getIntrinsicHeight();
         Bitmap bitmap = Bitmap.createBitmap(w,h, Config.ARGB_8888);
         Canvas canvas = newCanvas(bitmap);
         drawable.setBounds(0, 0, w, h);
         drawable.draw(canvas);
         return bitmap;
     }
     /**
      * 单位dp转单位px
      */
     public int dpTodx(int dp){
 
         return (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,
                 dp,getResources().getDisplayMetrics());
     }
 
     public int getType(){
         return mType;
     }
     /**
      * 设置图片类型：圆形、圆角矩形、椭圆形
      * @param mType
      */
     public void setType(int mType) {
         if(this.mType !=mType){
             this.mType = mType;
             invalidate();
         }
 
     }
     public int getRoundRadius() {
         return mRoundRadius;
     }
     /**
      * 设置圆角大小
      * @parammRoundRadius
      */
     public void setRoundRadius(int mRoundRadius) {
         if(this.mRoundRadius !=mRoundRadius){
             this.mRoundRadius =mRoundRadius;
             invalidate();
         }
 
     }
 }

 MainActivity类
 /****
  *
  * 自定义ImageView实现圆形图片，圆角矩形图片 椭圆图片
  *
  * @authorzq
  *
  */
 public class MainActivity extends Activity {
 
     private  ZQImageViewRoundOvaliv_circle;//圆形图片
     private ZQImageViewRoundOvaliv_roundRect;//圆角矩形图片
     private ZQImageViewRoundOvaliv_oval;//椭圆图片
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
       setContentView(R.layout.activity_image);
       initViews();
    }
    /**
     * 初始化Views
     */
    private void initViews(){
       iv_circle =(ZQImageViewRoundOval)findViewById(R.id.cicle);
       iv_roundRect =(ZQImageViewRoundOval)findViewById(R.id.roundRect);
       iv_oval =(ZQImageViewRoundOval)findViewById(R.id.oval);
 
       iv_roundRect.setType(ZQImageViewRoundOval.TYPE_ROUND);
       iv_roundRect.setRoundRadius(6);//矩形凹行大小
 
        iv_oval.setType(ZQImageViewRoundOval.TYPE_OVAL);
        iv_oval.setRoundRadius(45);//圆角大小
    }
 }

源码下载：

Eclipse下载：http://download.csdn.net/detail/dickyqie/9621330

AndroidStudio下载：https://github.com/DickyQie/android-imageview