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CircleImageView-方式2

96
Alex_Cin
2016.07.30 02:16* 字数 542

写一个圆形的ImageView 之前有一个通过paint.setXfermode方式去实现的,今天写一个更好地实现方式,国际惯例先看效果。

  • 先看原图

搜狗截图20160730020147.png

CropType.leftTop


004.png

CropType.centerTop


002.png

CropType.center


003.png

最后看代码 其实很简单,有错误请指出,谢谢

package github.alex.circleimageview;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapShader;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Shader;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.widget.ImageView;
/**
* 作者:alex
* 时间:2016/7/29 13:48
* 博客地址:http://www.jianshu.com/users/c3c4ea133871/subscriptions
*/
public class CircleImageView extends ImageView {
/**
* 绘图的Paint
*/
private Paint paint;
/**
* 圆角的半径
*/
private int radius;
/**
* 3x3 矩阵,主要用于缩小放大
*/
private Matrix matrix;
/**
* 渲染图像,使用图像为绘制图形着色
*/
private BitmapShader bitmapShader;
/**
* view的宽度
*/
private int width;
private String cropType;
public CircleImageView(Context context) {
super(context);
initView();
}
public CircleImageView(Context context, AttributeSet attrs) {
super(context, attrs);
initView();
}
/**
* 初始化 视图
*/
private void initView() {
matrix = new Matrix();
paint = new Paint();
paint.setAntiAlias(true);
radius = (int) dp2Px(10);
cropType = CropType.centerTop;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
width = Math.min(getMeasuredWidth(), getMeasuredHeight());
radius = width / 2;
setMeasuredDimension(width, width);
}
@Override
protected void onDraw(Canvas canvas) {
// super.onDraw(canvas);
if (getDrawable() == null) {
return;
}
initBitmapShader();
canvas.drawCircle(radius, radius, radius, paint);
}
/**
* 初始化BitmapShader
*/
private void initBitmapShader() {
Drawable drawable = getDrawable();
if (drawable == null) {
return;
}
Bitmap bmp = drawable2Bitmap(drawable);
bitmapShader = new BitmapShader(bmp, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
int bSize = Math.min(bmp.getWidth(), bmp.getHeight());
float scale = width * 1.0f / bSize;
matrix.setScale(scale, scale);
bitmapShader.setLocalMatrix(matrix);
paint.setShader(bitmapShader);
}
/**
* drawable转bitmap
*
* @param drawable
* @return
*/
private Bitmap drawable2Bitmap(Drawable drawable) {
int w = drawable.getIntrinsicWidth();
int h = drawable.getIntrinsicHeight();
Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
drawable.setBounds(0, 0, w, h);
if ((w >= h) && CropType.centerTop.equals(cropType)) {
canvas.translate((h - w) * 0.5F, 0);
} else if ((w >= h) && CropType.center.equals(cropType)) {
canvas.translate((h - w) * 0.5F, 0);
} else if ((w < h) && CropType.center.equals(cropType)) {
canvas.translate(0, (w - h) * 0.5F);
}
drawable.draw(canvas);
return bitmap;
}
public static final class CropType {
public static final String leftTop = "起点在左上角";
public static final String centerTop = "起点水平居中&垂直置顶";
public static final String center = "起点在图片中心";
}
/**
* 数据转换: dp---->px
*/
private float dp2Px(float dp) {
return dp * getContext().getResources().getDisplayMetrics().density;
}
}
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