mBitmapShader = new BitmapShader(bitmap, TileMode.CLAMP, TileMode.CLAMP);

@Override
 protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
  // TODO Auto-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);
  }

 }

/**
  * 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 = new BitmapShader(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);

 }

@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);
  }
 }

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:layout_width="match_parent"
 android:layout_height="match_parent"
 tools:context=".MainActivity" >

 <LinearLayout
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:gravity="center_horizontal"
  android:layout_marginTop="5dp"
  android:layout_marginBottom="25dp"
  android:orientation="vertical" >

  <com.czm.viewdrawtest.XCRoundAndOvalImageView
   android:id="@+id/cicleImageView"
   android:layout_width="200dp"
   android:layout_height="200dp"
   android:src="@drawable/img1" />

  <com.czm.viewdrawtest.XCRoundAndOvalImageView
   android:id="@+id/roundRectImageView"
   android:layout_width="200dp"
   android:layout_height="240dp"
   android:layout_marginTop="5dp"
   android:src="@drawable/img2" />

  <com.czm.viewdrawtest.XCRoundAndOvalImageView
   android:id="@+id/ovalImageView"
   android:layout_width="wrap_content"
   android:layout_height="wrap_content"
   android:layout_marginTop="5dp"
   android:src="@drawable/img3" />
 </LinearLayout>

</ScrollView>

package com.czm.viewdrawtest;


import android.app.Activity;
import android.os.Bundle;
import android.view.Window;
import android.view.WindowManager;
/**
 * 使用自定义ImageView
 * @author caizhiming
 *
 */
public class MainActivity extends Activity {

 private XCRoundAndOvalImageView circleImageView;//圆形图片
 private XCRoundAndOvalImageView roundRectImageView;//圆角矩形图片
 private XCRoundAndOvalImageView ovalImageView;//椭圆图片
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  //设置无标题 
  requestWindowFeature(Window.FEATURE_NO_TITLE); 
  //设置全屏 
  getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, 
    WindowManager.LayoutParams.FLAG_FULLSCREEN); 
  setContentView(R.layout.activity_main);
  
  initViews();
 }
 /**
  * 初始化Views
  */
 private void initViews(){
  circleImageView = (XCRoundAndOvalImageView)findViewById(R.id.cicleImageView);
  roundRectImageView = (XCRoundAndOvalImageView)findViewById(R.id.roundRectImageView);
  ovalImageView = (XCRoundAndOvalImageView)findViewById(R.id.ovalImageView);
  
  roundRectImageView.setType(XCRoundAndOvalImageView.TYPE_ROUND);
  roundRectImageView.setRoundRadius(100);
  
  ovalImageView.setType(XCRoundAndOvalImageView.TYPE_OVAL);
  ovalImageView.setRoundRadius(50);
  
 }
}