圆角图片

package com.archive.xunji.widgets;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.*;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.NinePatchDrawable;
import android.util.AttributeSet;
import android.widget.ImageView;
import com.archive.xunji.R;
import com.lidroid.xutils.bitmap.core.AsyncDrawable;

/**
 * 圆形ImageView，可设置最多两个宽度不同且颜色不同的圆形边框。
 *
 *
 */
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;
    private int mBorderInsideColor = 0;
    // 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.roundedimageview);
        mBorderThickness = a.getDimensionPixelSize(
                R.styleable.roundedimageview_border_thickness, 0);
        mBorderOutsideColor = a
                .getColor(R.styleable.roundedimageview_border_outside_color,
                        defaultColor);
        mBorderInsideColor = a.getColor(
                R.styleable.roundedimageview_border_inside_color, defaultColor);
    }

    @Override
    protected 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();--------------------注意这里解决不支持xutils

        Bitmap b = null;
        if(drawable instanceof BitmapDrawable){
            b =  ((BitmapDrawable)drawable).getBitmap() ;
        }else if(drawable instanceof AsyncDrawable){
            b = Bitmap
                    .createBitmap(
                            getWidth(),
                            getHeight(),
                            drawable.getOpacity() != PixelFormat.OPAQUE ? Bitmap.Config.ARGB_8888
                                    : Bitmap.Config.RGB_565);
            Canvas canvas1 = new Canvas(b);
            // canvas.setBitmap(bitmap);
            drawable.setBounds(0, 0, getWidth(),
                    getHeight());
            drawable.draw(canvas1);
        }


        Bitmap bitmap = b.copy(Bitmap.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
     *
     * @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(), Bitmap.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(PorterDuff.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
     */
    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);
    }

}

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="roundedimageview">
        <attr name="border_thickness" format="dimension" />
        <attr name="border_inside_color" format="color" />
        <attr name="border_outside_color" format="color"></attr>
    </declare-styleable>
</resources>

<com.archive.xunji.widgets.RoundImageView
           android:id="@+id/iv_touxiang_guangchangfragment"
           android:layout_alignBottom="@id/tv_username_guangchangfragment"
           android:layout_toLeftOf="@id/tv_username_guangchangfragment"
           android:layout_marginRight="5dp"
           android:layout_width="30dp"
           android:layout_height="30dp"
           android:src="@mipmap/ic_launcher"
           />

 圆形图片最主要的方法   paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));

意思是取两个元素在画布上的交集然后取上层部分显示  如此将圆形图片展示出来