获取圆形图片

开发中经常用到圆形的头像，显得漂亮些，代码如下

package com.qianniu.stock.view;


import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.PorterDuff.Mode;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.graphics.drawable.BitmapDrawable;
import android.util.AttributeSet;
import android.widget.ImageView;


public class RoundedImageView extends ImageView {
private int mBorderThickness = 0;
private int mBorderColor = Color.WHITE;


public RoundedImageView(Context context) {
super(context);
}


public RoundedImageView(Context context, AttributeSet attrs) {
super(context, attrs);
setCustomAttributes(attrs);
}


public RoundedImageView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
setCustomAttributes(attrs);
}


private void setCustomAttributes(AttributeSet attrs) {
mBorderThickness = 2;
mBorderColor = Color.parseColor("#ffffff");
}


@Override
protected void onDraw(Canvas canvas) {


Drawable drawable = getDrawable();


if (drawable == null) {
return;
}


if (getWidth() == 0 || getHeight() == 0) {
return;
}
this.measure(0, 0);


Bitmap b = ((BitmapDrawable) drawable).getBitmap();
Bitmap bitmap = b.copy(Bitmap.Config.ARGB_8888, true);


int w = getWidth(), h = getHeight();


int radius = (w < h ? w : h) / 2 - mBorderThickness;
Bitmap roundBitmap = getCroppedBitmap(bitmap, radius);


final Paint paint = new Paint();
paint.setAntiAlias(true);
paint.setFilterBitmap(true);
paint.setDither(true);
paint.setColor(mBorderColor);
canvas.drawCircle(w / 2, h / 2, radius + mBorderThickness, paint);
canvas.drawBitmap(roundBitmap, w / 2 - radius, h / 2 - radius, null);


}


private Bitmap getCroppedBitmap(Bitmap bmp, int radius) {
Bitmap scaledSrcBmp;
int diameter = radius * 2;
if (bmp.getWidth() != diameter || bmp.getHeight() != diameter)
scaledSrcBmp = Bitmap.createScaledBitmap(bmp, diameter, diameter, false);
else
scaledSrcBmp = bmp;
Bitmap output = Bitmap.createBitmap(scaledSrcBmp.getWidth(), scaledSrcBmp.getHeight(),
Config.ARGB_8888);
Canvas canvas = new Canvas(output);


final Paint paint = new Paint();
final 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);
paint.setColor(mBorderColor);
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);


return output;
}


}

说白了，就是一个自定义ImageView，直接加在控件里就行