android 一个简单的实现圆形头像的Demo

【实例截图】

【核心代码】

package davidzoomimageviewrounddemo.qq986945193.com.davidzoomimageviewrounddemo.view;

import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.graphics.PorterDuff;
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;

import davidzoomimageviewrounddemo.qq986945193.com.davidzoomimageviewrounddemo.R;

/**
 * @author ：程序员小冰
 * @新浪微博 ：http://weibo.com/mcxiaobing
 * @CSDN博客: http://blog.csdn.net/qq_21376985
 * @交流Qq ：986945193
 * @GitHub:https://github.com/QQ986945193
 */
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);
    }

    @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();
        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
     *
     * 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(), 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
     *
     * 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);
    }

}