欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  移动技术

Android应用中绘制圆形头像的方法解析

程序员文章站 2024-02-22 19:01:36
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 radialgradien...

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