Question

i) 写了一条灯片,显示一只ta子,能够从蓝色到洋上获得有关石灰的数据。当数据变化时,即更换针头和其他图像在屏幕上显示现有数值的意见。

轮值代码:

bMapRpm=bMapcanvasBackTacho.copy(bMapcanvasBackTacho.getConfig(), true);
canvasRpm.setBitmap(bMapRpm);
canvasRpm.save();
canvasRpm.rotate((float)Rpmdegree+(float)Rpmcurrentdegree,bMapRpm.getWidth()/2,bMapRpm.getHeight()/2);
canvasRpm.drawBitmap(bMapNadel,0,0,paint);
canvasRpm.restore();

bMapcanvasBackTacho is just a transparent background. bMapNadel is the bitmap of the needle. bMapRpm is the bitmap of the canvas to draw on

更新形象观点一:

ivNadel.setImageBitmap(bMapRpm);

i tryed out what slows the app by commenting parts of the code out. after commenting the setImageBitmap() out the slow down disapeared.

谁知道如何更新形象另一种方式或轮式的观念可能会改变,使其更快地工作?

thx =

Answer 1

You can do two things:
First, don t call copy() each time you need to update the Bitmap this creates a new Bitmap and is both time and memory consuming.
Second, call invalidate() on the ImageView. This will notify the View that something has changed and it redraws itself without having to update anything else that is happening when you replace the Bitmap completely.

最后,你甚至可能想建立你自己。观点执行,使你只能凌驾于<条码>onDraw(<>/条码>,并在那里进行轮换。

友情链接