易采站长站为您分析Android应用中绘制圆形头像的方法解析,文后还顺带介绍了Android App常用图标尺寸规范,需要的朋友可以参考下
要画这种圆形带阴影的头像，个人分解成三个图层
1,先画头像边缘的渐变
RadialGradient gradient = new RadialGradient(j/2,k/2,j/2,new int[]{0xff5d5d5d,0xff5d5d5d,0x00ffffff},new float[]{0.f,0.8f,1.0f}, Shader.TileMode.CLAMP);
paint.setShader(gradient);
canvas.drawCircle(j/2,k/2,j/2,paint);
2,截去出圆形头像Bitmap
/**
* 转换图片成圆形
* @param bitmap 传入Bitmap对象
* @return
*/
public Bitmap toRoundBitmap(Bitmap bitmap)
{
int width = bitmap.getWidth();
int height = bitmap.getHeight();
float roundPx;
float left,top,right,bottom,dst_left,dst_top,dst_right,dst_bottom;
if (width <= height) {
roundPx = width / 2 -5;
top = 0;
bottom = width;
left = 0;
right = width;
height = width;
dst_left = 0;
dst_top = 0;
dst_right = width;
dst_bottom = width;
} else {
roundPx = height / 2 -5;
float clip = (width - height) / 2;
left = clip;
right = width - clip;
top = 0;
bottom = height;
width = height;
dst_left = 0;
dst_top = 0;
dst_right = height;
dst_bottom = height;
}
Bitmap output = Bitmap.createBitmap(width,
height, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final int color = 0xff424242;
final Paint paint = new Paint();
final Rect src = new Rect((int)left, (int)top, (int)right, (int)bottom);
final Rect dst = new Rect((int)dst_left, (int)dst_top, (int)dst_right, (int)dst_bottom);
final RectF rectF = new RectF(dst_left+15, dst_top+15, dst_right-20, dst_bottom-20);
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(bitmap, src, dst, paint);
return output;
}
