clearRect后无法在画布上绘制图像

Question

i am having some trouble with the following code. Essentially this is wrapped up in an image uploader. So once the uploader completes its callback the following code gets executed:

var c = canvas.getContext('2d');
var logoImage = new Image();
logoImage.onload = function() {

   c.clearRect(0, 0, canvas.width, canvas.height);
   c.drawImage(logoImage, 0, 0, 200, 300); // i've simplified this call...
}
logoImage.src = "/path/to/" + fileName;

So this works the first time. But I expected that it would work subsequent times as well. So when another image is uploaded, the canvas is cleared and that image is drawn. Instead what happens is that the canvas is cleared but no further drawing takes place...

Any ideas?

Answer 1

try this:

replace the

 c.clearRect(0, 0, canvas.width, canvas.height);

with:

canvas.width=canvas.width;