android 实现圆角图片

package com.eightzero.cityinformations.util;import android.content.Context;import android.content.res.TypedArray;import android.graphics.Bitmap;import android.graphics.BitmapShader;import android.graphics.Canvas;import android.graphics.Matrix;import android.graphics.Paint;import android.graphics.RectF;import android.graphics.Shader.TileMode;import android.graphics.drawable.BitmapDrawable;import android.graphics.drawable.Drawable;import android.os.Bundle;import android.os.Parcelable;import android.util.AttributeSet;import android.util.Log;import android.util.TypedValue;import android.widget.ImageView;import com.eightzero.cityinformations.R;/** * http://blog.csdn.net/lmj623565791/article/details/41967509 *  * @author zhy *  */public class RoundImageView extends ImageView{/** * 图片的类型，圆形or圆角 */private int type;public static final int TYPE_CIRCLE = 0;public static final int TYPE_ROUND = 1;/** * 圆角大小的默认值 */private static final int BODER_RADIUS_DEFAULT = 10;/** * 圆角的大小 */private int mBorderRadius;/** * 绘图的Paint */private Paint mBitmapPaint;/** * 圆角的半径 */private int mRadius;/** * 3x3 矩阵，主要用于缩小放大 */private Matrix mMatrix;/** * 渲染图像，使用图像为绘制图形着色 */private BitmapShader mBitmapShader;/** * view的宽度 */private int mWidth;private RectF mRoundRect;public RoundImageView(Context context, AttributeSet attrs){super(context, attrs);mMatrix = new Matrix();mBitmapPaint = new Paint();mBitmapPaint.setAntiAlias(true);TypedArray a = context.obtainStyledAttributes(attrs,R.styleable.RoundImageView);mBorderRadius = a.getDimensionPixelSize(R.styleable.RoundImageView_borderRadius, (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,BODER_RADIUS_DEFAULT, getResources().getDisplayMetrics()));// 默认为10dptype = a.getInt(R.styleable.RoundImageView_type, TYPE_CIRCLE);// 默认为Circlea.recycle();}public RoundImageView(Context context){this(context, null);}@Overrideprotected void onMeasure(int widthMeasureSpec, int heightMeasureSpec){super.onMeasure(widthMeasureSpec, heightMeasureSpec);/** * 如果类型是圆形，则强制改变view的宽高一致，以小值为准 */if (type == TYPE_CIRCLE){mWidth = Math.min(getMeasuredWidth(), getMeasuredHeight());mRadius = mWidth / 2;setMeasuredDimension(mWidth, mWidth);}}/** * 初始化BitmapShader */private void setUpShader(){Drawable drawable = getDrawable();if (drawable == null){return;}Bitmap bmp = drawableToBitamp(drawable);// 将bmp作为着色器，就是在指定区域内绘制bmpmBitmapShader = new BitmapShader(bmp, TileMode.CLAMP, TileMode.CLAMP);float scale = 1.0f;if (type == TYPE_CIRCLE){// 拿到bitmap宽或高的小值int bSize = Math.min(bmp.getWidth(), bmp.getHeight());scale = mWidth * 1.0f / bSize;} else if (type == TYPE_ROUND){Log.e("TAG","b'w = " + bmp.getWidth() + " , " + "b'h = "+ bmp.getHeight());if (!(bmp.getWidth() == getWidth() && bmp.getHeight() == getHeight())){// 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 / bmp.getWidth(),getHeight() * 1.0f / bmp.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);// 设置shadermBitmapPaint.setShader(mBitmapShader);}@Overrideprotected void onDraw(Canvas canvas){Log.e("TAG", "onDraw");if (getDrawable() == null){return;}setUpShader();if (type == TYPE_ROUND){canvas.drawRoundRect(mRoundRect, mBorderRadius, mBorderRadius,mBitmapPaint);} else{canvas.drawCircle(mRadius, mRadius, mRadius, mBitmapPaint);// drawSomeThing(canvas);}}@Overrideprotected void onSizeChanged(int w, int h, int oldw, int oldh){super.onSizeChanged(w, h, oldw, oldh);// 圆角图片的范围if (type == TYPE_ROUND)mRoundRect = new RectF(0, 0, w, h);}/** * drawable转bitmap *  * @param drawable * @return */private Bitmap drawableToBitamp(Drawable drawable){if (drawable instanceof BitmapDrawable){BitmapDrawable bd = (BitmapDrawable) drawable;return bd.getBitmap();}int w = drawable.getIntrinsicWidth();int h = drawable.getIntrinsicHeight();Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);Canvas canvas = new Canvas(bitmap);drawable.setBounds(0, 0, w, h);drawable.draw(canvas);return bitmap;}private static final String STATE_INSTANCE = "state_instance";private static final String STATE_TYPE = "state_type";private static final String STATE_BORDER_RADIUS = "state_border_radius";@Overrideprotected Parcelable onSaveInstanceState(){Bundle bundle = new Bundle();bundle.putParcelable(STATE_INSTANCE, super.onSaveInstanceState());bundle.putInt(STATE_TYPE, type);bundle.putInt(STATE_BORDER_RADIUS, mBorderRadius);return bundle;}@Overrideprotected void onRestoreInstanceState(Parcelable state){if (state instanceof Bundle){Bundle bundle = (Bundle) state;super.onRestoreInstanceState(((Bundle) state).getParcelable(STATE_INSTANCE));this.type = bundle.getInt(STATE_TYPE);this.mBorderRadius = bundle.getInt(STATE_BORDER_RADIUS);} else{super.onRestoreInstanceState(state);}}public void setBorderRadius(int borderRadius){int pxVal = dp2px(borderRadius);if (this.mBorderRadius != pxVal){this.mBorderRadius = pxVal;invalidate();}}public void setType(int type){if (this.type != type){this.type = type;if (this.type != TYPE_ROUND && this.type != TYPE_CIRCLE){this.type = TYPE_CIRCLE;}requestLayout();}}public int dp2px(int dpVal){return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP,dpVal, getResources().getDisplayMetrics());}}

使用时直接在xml布局中，直接引用即可

<pre name="code" class="html"><com.eightzero.cityinformations.util.RoundImageView            android:id="@+id/iv_shop_logo"            android:layout_width="match_parent"            android:layout_height="168dp"            android:contentDescription="@null"            android:scaleType="centerCrop"            app:borderRadius="5dp" />