javascript - load image to fabric canvas background - Stack Overflow

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hi im trying to upload an image and put it as canvas background. code snippet:

function handleMenuImage(e){
    var reader = new FileReader();
    reader.onload = function(event){
        var img = new Image();
        img.src = event.target.result;
        canvas.setWidth(img.width);
        canvas.setHeight(img.height);
        canvas.setBackgroundImage(img.src, canvas.renderAll.bind(canvas));

        //set the page background
        menuPages[currentPage].pageBackground.src = img.src;
        canvas.backgroundImageStretch = false;

    }
    reader.readAsDataURL(e.target.files[0]); 
}

the problem is that the canvas not showing the background. i can see the canvas background src in chrome devtools. the background is actually have been set but somehow its not displayed.

hi im trying to upload an image and put it as canvas background. code snippet:

function handleMenuImage(e){
    var reader = new FileReader();
    reader.onload = function(event){
        var img = new Image();
        img.src = event.target.result;
        canvas.setWidth(img.width);
        canvas.setHeight(img.height);
        canvas.setBackgroundImage(img.src, canvas.renderAll.bind(canvas));

        //set the page background
        menuPages[currentPage].pageBackground.src = img.src;
        canvas.backgroundImageStretch = false;

    }
    reader.readAsDataURL(e.target.files[0]); 
}

the problem is that the canvas not showing the background. i can see the canvas background src in chrome devtools. the background is actually have been set but somehow its not displayed.

• javascript
• canvas
• html5-canvas
• filereader
• fabricjs

Share Improve this question Follow asked Jul 12, 2012 at 13:25 Evgeni RoitburgEvgeni Roitburg 2,0972323 silver badges3636 bronze badges

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2 Answers 2

Sorted by: Reset to default 2

That seems strangely confusing. If you want a background image on an HTMLCanvasElement, why not just set the background image via CSS?

#myCanvas {
  background-image: url(http://placekitten./100/100);
}

Or set the CSS via JavaScript:

canvas.style.backgroundImage = 'url(http://placekitten./100/100)';

Try the following code:

var raw_reader = new FileReader();
raw_reader.onload = function (event){
  var reader = new FileReader();
  reader.onload = function(event){
    var img = new Image();
    img.src = event.target.result;
    canvas.setWidth(img.width);
    canvas.setHeight(img.height);
    canvas.setBackgroundImage(img.src, canvas.renderAll.bind(canvas));

    //set the page background
    menuPages[currentPage].pageBackground.src = img.src;
    canvas.backgroundImageStretch = false;

  }
  reader.readAsDataURL(e.target.files[0]); 
}
raw_reader.readAsBinaryString(e.target.files[0]);

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