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Home Web Front-end HTML Tutorial Problems with canvas and drawImage, experts can quickly learn_html/css_WEB-ITnose

Problems with canvas and drawImage, experts can quickly learn_html/css_WEB-ITnose

Jun 24, 2016 pm 12:18 PM

代码如下:








jQuery(function ($) {
$("img").load(function () {
var w = $(this).width(),
h = $(this).height();
$(this).after($("").css({"width": w, "height": h, "backgroundColor": "blue"}));
var ctx = $(this).next("canvas")[0].getContext("2d");
ctx.drawImage($(this)[0], 0, 0, w, h);
});
});







drawImage出来的图片尺寸变形,不是原来图片的形状,会看到canvas背景蓝色。


回复讨论(解决方案)

请问你用的是什么浏览器呀???我用的chrome opera ie9貌似都没有你说的问题

.after($("")


canvas的实际宽高(canvas代码种实际参考的大小) 要这样设置  否则默认是 300-150
样式里面的 宽高 代表 渲染大小

实际宽高 和  样式 宽高 不一致  就会拉伸了

canvas画布的尺寸没问题,用drawImage画出来的图片与源img节点尺寸不一样

canvas里面的width和height跟css里面的width和height是不一样的,我以前就被坑过。。 统一用canvas.width比较好,画板的坐标神马的跟这个width是一样的,跟css里面的不一样

canvas画布的尺寸没问题,用drawImage画出来的图片与源img节点尺寸不一样
2楼已经和你说的很清楚了

谢了各位,解决了

怎么解决的呀,也碰到了同样的问题,望楼主告知下解决的方法哦!!

怎么解决的呀,也碰到了同样的问题,望楼主告知下解决的方法哦!!
canvas的width和height要设置成属性而不是样式
就是这种 
不是  和 canvas {width: 400px; height: 300px;}

原来如此。。。。 坑了我好久。。。。

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