Android应用中绘制圆形头像的方法解析
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;
}
3,最后画上白边
Paint paint = new Paint();
paint.setColor(0xffffffff);
paint.setStrokeWidth(10);
paint.setStyle(Paint.Style.STROKE);
canvas.drawCircle(j/2,k/2,j/2-20,paint);
PS:Android App常用图标尺寸规范
1. 程序启动图标:
LDPI (Low Density Screen,120 DPI),其图标大小为 36 x 36 px。
MDPI (Medium Density Screen, 160 DPI),其图标大小为 48 x 48 px。
HDPI (High Density Screen, 240 DPI),其图标大小为 72 x 72 px。
xhdpi (Extra-high density screen, 320 DPI),其图标大小为 96 x 96 px。
xxhdpi(xx-high density screen, 480 DPI),其图标大小为144 x 144 px。
2.底部菜单图标
(1)大屏:
完整图片(红色): 72 x 72 px
图标(蓝色): 48 x 48 px
图标外边框(粉色): 44 x 44 px
(2)中屏:
完整图片: 48 x 48 px
图标: 32 x 32 px
图标外边框: 30 x 30 px
(3)小屏:
完整图片: 36 x 36 px
图标: 24 x 24 px
图标外边框: 22 x 22 px
3. 弹出对话框顶部图标
小屏 24 x 24 px Low density screen (ldpi)
中屏 32 x 32 px Medium density screen (mdpi)
大屏 48 x 48 px High density screen (hdpi)
4. 长列表内部列表项图标
小屏 24 x 24 px Low density screen (ldpi)
中屏 32 x 32 px Medium density screen (mdpi)
大屏 48 x 48 px High density screen (hdpi)
5. 底部或顶部tab标签图标
(1)大屏 (hdpi) screens:
完整图片(红色): 48 x 48 px
图标(蓝色): 42 x 42 px
(2)中屏 (mdpi) screens:
完整图片: 32 x 32 px
图标: 28 x 28 px
(3)小屏(ldpi) screens:
完整图片: 24 x 24 px
图标: 22 x 22 px
6. 底部状态栏图标
ldpi (120 dpi) 18 x 18 px 小屏
mdpi (160 dpi) 24 x 24 px 中屏
hdpi (240 dpi) 36 x 36 px 大屏
xhdpi (320 dpi) 48 x 48 px 特大屏
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