Android 自定义圆角图片/头像

之前多次做项目要用圆角图片都去网上找现成的。
今天想想不行，还是得自己学会，所以就看了这篇文章

http://blog.csdn.net/goodlixueyong/article/details/49614485

后自定义了一个，集成自ImageView，

效果如图:


 


代码如下：

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.RectF;
import android.graphics.drawable.BitmapDrawable;
import android.util.AttributeSet;
import android.widget.ImageView;

import com.eccic.quicksolve_android.R;

/**
* Created by eccic on 17/1/3.
*/
public class RoundImageView extends ImageView {
public RoundImageView(Context context) {
this(context, null);
}

private float cornerRadius = -1;
private Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);

public RoundImageView(Context context, AttributeSet attrs) {
super(context, attrs);

TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.RoundImageView);
for (int i = 0; i < typedArray.getIndexCount(); i++) {
switch (typedArray.getIndex(i)) {
case R.styleable.RoundImageView_cornerRadius:
cornerRadius = typedArray.getDimension(R.styleable.RoundImageView_cornerRadius, cornerRadius);
break;
}
}
}

@Override
protected void onDraw(Canvas canvas) {
if (cornerRadius < 0) cornerRadius = Math.min(getWidth(), getHeight()) * 0.5f;
BitmapDrawable bitmapDrawable = (BitmapDrawable) getDrawable();
if (bitmapDrawable != null) {
//步骤1：先生成一个bitmap，在bitmap上绘制原图

9404
Bitmap bitmap = Bitmap.createBitmap(getWidth(),getHeight(), Bitmap.Config.ARGB_8888);
Canvas bitmapCanvas = new Canvas(bitmap);
bitmapDrawable.setBounds(0, 0, getWidth(), getHeight());
bitmapDrawable.draw(bitmapCanvas);
//步骤2：生成圆形图片蒙版
Bitmap mask = Bitmap.createBitmap(getWidth(), getHeight(),Bitmap.Config.ARGB_8888);
Canvas maskCanvas = new Canvas(mask);
maskCanvas.drawRoundRect(new RectF(0, 0, getWidth(), getHeight()), cornerRadius, cornerRadius, paint);
//步骤3：使用DST_IN的方式在原图的bitmap上绘制蒙版图
paint.reset();
paint.setFilterBitmap(false);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));
bitmapCanvas.drawBitmap(mask, 0.0f, 0.0f, paint);
//步骤4：将最后生成的这个bitmap绘制到View的canvas上
if (bitmap != null) {
paint.setXfermode(null);
canvas.drawBitmap(bitmap, 0.0f, 0.0f, paint);
}
}
}
}res→values→attrs中添加：
<?xml version="1.0" encoding="utf-8"?>
<resources>

......

<declare-styleable name="RoundImageView">
<attr name="cornerRadius" format="dimension" />
</declare-styleable>

</resources>