作者：程序员小冰，CSDN博客：http://blog.csdn.net/qq_21376985
QQ986945193 博客园主页：http://www.cnblogs.com/mcxiaobing/

Android开发之制作圆形头像自定义View,直接引用工具类，加快开发速度。带有源代码学习

大家都知道。现在好多头像都是圆形的，不再是以前的正方形或者长方形。
因此今天给大家带来的就是如何制作一个圆形头像。下面是效果图：

当然利用一个自定义View集成ImageView即可。

package com.qq986945193.zoomimageviewrounddemo;import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.NinePatchDrawable;
import android.util.AttributeSet;
import android.widget.ImageView;/*** 微博：http://weibo.com/mcxiaobing* ============================================================================* Copyright (c) 2015-2016 QQ986945193 All rights reserved.* ----------------------------------------------------------------------------* 类名：自定义圆形头像View* ----------------------------------------------------------------------------* 功能描述：http://blog.csdn.net/qq_21376985* ----------------------------------------------------------------------------*/public class RoundImageView extends ImageView {private int mBorderThickness = 0;private Context mContext;private int defaultColor = 0xFFFFFFFF;// 如果只有其中一个有值，则只画一个圆形边框private int mBorderOutsideColor = 0;// 图片的外边界private int mBorderInsideColor = 0;// 图片的内边界// 控件默认长、宽private int defaultWidth = 0;private int defaultHeight = 0;public RoundImageView(Context context) {super(context);mContext = context;}public RoundImageView(Context context, AttributeSet attrs) {super(context, attrs);mContext = context;setCustomAttributes(attrs);}public RoundImageView(Context context, AttributeSet attrs, int defStyle) {super(context, attrs, defStyle);mContext = context;setCustomAttributes(attrs);}private void setCustomAttributes(AttributeSet attrs) {TypedArray a = mContext.obtainStyledAttributes(attrs,R.styleable.RoundImageView);// 边界的宽度mBorderThickness = a.getDimensionPixelSize(R.styleable.RoundImageView_border_thickness, 0);// 外边界的颜色mBorderOutsideColor = a.getColor(R.styleable.RoundImageView_border_outside_color, defaultColor);// 内边界的颜色mBorderInsideColor = a.getColor(R.styleable.RoundImageView_border_inside_color, defaultColor);}@Overrideprotected void onDraw(Canvas canvas) {Drawable drawable = getDrawable();if (drawable == null) {return;}if (getWidth() == 0 || getHeight() == 0) {return;}this.measure(0, 0);if (drawable.getClass() == NinePatchDrawable.class)return;Bitmap b = ((BitmapDrawable) drawable).getBitmap();Bitmap bitmap = b.copy(Config.ARGB_8888, true);if (defaultWidth == 0) {defaultWidth = getWidth();}if (defaultHeight == 0) {defaultHeight = getHeight();}// 保证重新读取图片后不会因为图片大小而改变控件宽、高的大小（针对宽、高为wrap_content布局的imageview，但会导致margin无效）// if (defaultWidth != 0 && defaultHeight != 0) {// LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(// defaultWidth, defaultHeight);// setLayoutParams(params);// }int radius = 0;if (mBorderInsideColor != defaultColor&& mBorderOutsideColor != defaultColor) {// 定义画两个边框，分别为外圆边框和内圆边框radius = (defaultWidth < defaultHeight ? defaultWidth: defaultHeight) / 2 - 2 * mBorderThickness;// 画内圆drawCircleBorder(canvas, radius + mBorderThickness / 2,mBorderInsideColor);// 画外圆drawCircleBorder(canvas, radius + mBorderThickness+ mBorderThickness / 2, mBorderOutsideColor);} else if (mBorderInsideColor != defaultColor&& mBorderOutsideColor == defaultColor) {// 定义画一个边框radius = (defaultWidth < defaultHeight ? defaultWidth: defaultHeight) / 2 - mBorderThickness;drawCircleBorder(canvas, radius + mBorderThickness / 2,mBorderInsideColor);} else if (mBorderInsideColor == defaultColor&& mBorderOutsideColor != defaultColor) {// 定义画一个边框radius = (defaultWidth < defaultHeight ? defaultWidth: defaultHeight) / 2 - mBorderThickness;drawCircleBorder(canvas, radius + mBorderThickness / 2,mBorderOutsideColor);} else {// 没有边框radius = (defaultWidth < defaultHeight ? defaultWidth: defaultHeight) / 2;}Bitmap roundBitmap = getCroppedRoundBitmap(bitmap, radius);canvas.drawBitmap(roundBitmap, defaultWidth / 2 - radius, defaultHeight/ 2 - radius, null);}/*** 获取裁剪后的圆形图片* * http://blog.csdn.net/qq_21376985* @param radius*            半径*/public Bitmap getCroppedRoundBitmap(Bitmap bmp, int radius) {Bitmap scaledSrcBmp;int diameter = radius * 2;// 为了防止宽高不相等，造成圆形图片变形，因此截取长方形中处于中间位置最大的正方形图片int bmpWidth = bmp.getWidth();int bmpHeight = bmp.getHeight();int squareWidth = 0, squareHeight = 0;int x = 0, y = 0;Bitmap squareBitmap;if (bmpHeight > bmpWidth) {// 高大于宽squareWidth = squareHeight = bmpWidth;x = 0;y = (bmpHeight - bmpWidth) / 2;// 截取正方形图片squareBitmap = Bitmap.createBitmap(bmp, x, y, squareWidth,squareHeight);} else if (bmpHeight < bmpWidth) {// 宽大于高squareWidth = squareHeight = bmpHeight;x = (bmpWidth - bmpHeight) / 2;y = 0;squareBitmap = Bitmap.createBitmap(bmp, x, y, squareWidth,squareHeight);} else {squareBitmap = bmp;}if (squareBitmap.getWidth() != diameter|| squareBitmap.getHeight() != diameter) {scaledSrcBmp = Bitmap.createScaledBitmap(squareBitmap, diameter,diameter, true);} else {scaledSrcBmp = squareBitmap;}Bitmap output = Bitmap.createBitmap(scaledSrcBmp.getWidth(),scaledSrcBmp.getHeight(), Config.ARGB_8888);Canvas canvas = new Canvas(output);Paint paint = new Paint();Rect rect = new Rect(0, 0, scaledSrcBmp.getWidth(),scaledSrcBmp.getHeight());paint.setAntiAlias(true);paint.setFilterBitmap(true);paint.setDither(true);canvas.drawARGB(0, 0, 0, 0);canvas.drawCircle(scaledSrcBmp.getWidth() / 2,scaledSrcBmp.getHeight() / 2, scaledSrcBmp.getWidth() / 2,paint);paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));canvas.drawBitmap(scaledSrcBmp, rect, rect, paint);// bitmap回收(recycle导致在布局文件XML看不到效果)// bmp.recycle();// squareBitmap.recycle();// scaledSrcBmp.recycle();bmp = null;squareBitmap = null;scaledSrcBmp = null;return output;}/*** 边缘画圆* * http://blog.csdn.net/qq_21376985*/private void drawCircleBorder(Canvas canvas, int radius, int color) {Paint paint = new Paint();/* 去锯齿 */paint.setAntiAlias(true);paint.setFilterBitmap(true);paint.setDither(true);paint.setColor(color);/* 设置paint的　style　为STROKE：空心 */paint.setStyle(Paint.Style.STROKE);/* 设置paint的外框宽度 */paint.setStrokeWidth(mBorderThickness);canvas.drawCircle(defaultWidth / 2, defaultHeight / 2, radius, paint);}}

然后我们需要在布局中引用。下面是布局的一个引用，其实很简单，就和咱们
引用自定义View一模一样。由于它继承了ImageView。所以，方法大致相同。

 <com.qq986945193.zoomimageviewrounddemo.RoundImageViewandroid:layout_width="100dp"android:layout_height="100dp"android:layout_centerInParent="true"android:scaleType="fitCenter"android:src="@drawable/img" />

当然还有，我们写了一个样式，所以需要在styles样式中添加：

   <!-- 圆形ImageView --><declare-styleable name="RoundImageView"><attr name="border_thickness" format="dimension" /><attr name="border_inside_color" format="color" /><attr name="border_outside_color" format="color" /></declare-styleable>

OK,这样，圆形的的效果就能出来了，是不是很简单呢？当然，自定义View那一块想了解的可以深入。毕竟，你只会用，看不懂源代码也是不太好吧？是不是呢？
（Eclipse版本）源代码传送门：
http://download.csdn.net/detail/qq_21376985/9599249
（Android Studio版本）源代码传送门：
https://github.com/QQ986945193/DavidZoomImageViewRoundDemo