复制代码 代码如下:
function drawimage(imgd, fitwidth, fitheight) {
    var image = new image();
    image.src = imgd.src;
    if (image.width > 0 && image.height > 0) {
        if (image.width / image.height >= fitwidth / fitheight) {
            if (image.width > fitwidth) {
                imgd.width = fitwidth;
                imgd.height = (image.height * fitwidth) / image.width;
            } else {
                imgd.width = image.width;
                imgd.height = image.height;
            }
        } else {
            if (image.height > fitheight) {
                imgd.height = fitheight;
                imgd.width = (image.width * fitheight) / image.height;
            } else {
                imgd.width = image.width;
                imgd.height = image.height;
            }
        }
    }
}