android 放大镜ShapeDrawable妙用分享
首先,ShapeDrawable构造的时候可以指定描画的形状,
其次,可以通过shape.getPaint().setShader();指定Shader,shader可以接受一个图片和matrix
所以问题就顺利的解决了:)
float scale = 1.2f;
int cx = 224;
int cy = 357;
int r = 200;
// 指定形状创建一个ShapeDrawable
ShapeDrawable shape=new ShapeDrawable(new OvalShape());
Bitmap bm = BitmapFactory.decodeResource(getResources(),R.drawable.bg1);
BitmapShader bs = new BitmapShader(bm, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
Matrix m = new Matrix();
m.setTranslate(r-cx, r-cy);
m.postScale(scale, scale);
bs.setLocalMatrix(m); // 图形变换可以在这里实现,包括区域指定
// 为ShapeDrawable设置Shader
shape.getPaint().setShader(bs);
// 指定描画目标位置
shape.setBounds((int)(cx-r*scale),(int)(cy-r*scale),(int)(cx+r*scale),(int)(cy+r*scale));
canvas.drawBitmap(bm, 0, 0, null);
shape.draw(canvas);
float scale = 1.2f;
int cx = 224;
int cy = 357;
int r = 200;
// 指定形状创建一个ShapeDrawable
ShapeDrawable shape=new ShapeDrawable(new OvalShape());
Bitmap bm = BitmapFactory.decodeResource(getResources(),R.drawable.bg1);
BitmapShader bs = new BitmapShader(bm, Shader.TileMode.CLAMP, Shader.TileMode.CLAMP);
Matrix m = new Matrix();
m.setTranslate(r-cx, r-cy);
m.postScale(scale, scale);
bs.setLocalMatrix(m); // 图形变换可以在这里实现,包括区域指定
// 为ShapeDrawable设置Shader
shape.getPaint().setShader(bs);
// 指定描画目标位置
shape.setBounds((int)(cx-r*scale),(int)(cy-r*scale),(int)(cx+r*scale),(int)(cy+r*scale));
canvas.drawBitmap(bm, 0, 0, null);
shape.draw(canvas);