javascript - 将图像填充到 Canvas 中

标签 javascript jquery html image canvas

我有一个base64图像字符串,我创建了一个 Canvas 并将base64与图像一起放置,并将 Canvas 高度指定为481,宽度指定为650,当我尝试在html中显示图像时,图像即将到来,但它是没有完全填满 Canvas ,

任何人都可以告诉我一些解决方案来将图像填充到整个 Canvas 中,无论图片的质量如何。

我的代码如下所示

<强> JSFiddle

 var base64 = "data:image/jpeg;base64,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";
var canvas = document.createElement('canvas');
canvas.width = 650;
canvas.height = 481;
var ctx = canvas.getContext("2d");
var image = new Image();
image.onload = function () {
    ctx.drawImage(image, 0, 0);
};
image.src = base64;
$('#showImage').html(canvas);

最佳答案

将 onload 函数体更改为

ctx.drawImage(图像, 0, 0, 650, 481);

关于javascript - 将图像填充到 Canvas 中,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/29861127/

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