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

以上是 Android应用中绘制圆形头像的方法解析 的全部内容, 来源链接: utcz.com/z/320569.html

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