Javascript - 图像onload

Question

我的js文件中有一个函数来获取文件高度。

Util.isImageSize(document.getElementById('fileImage'), function(height) { 
    alert(height);
});

这是我调用函数的地方

Uncaught TypeError: callback is not a function at Image.image.onload 

我收到的错误是

source /proj/common/tools/repo/etc/profile.d/repo.sh
repo project init $branch
repo project sync
source poky/fnc-init-build-env build
bitbake -g $image

我现在真的被困在这个

Answer 1

我不确定你在找什么，但我仍然可以提醒图像高度

var Util = {};

Util.isImageSize = function (file, callback) {
    console.log(file);
    var fileUpload = file;
    var reader = new FileReader();
    reader.readAsDataURL(fileUpload.files[0]);
    reader.onload = function (e) {
        var image = new Image();
        image.src = e.target.result;
        image.onload = function () {
            var height = this.height;
            callback(height);
        };
    }
}


document.getElementById('fileImage').addEventListener('change', function() {
    Util.isImageSize(this, function(height) { 
    alert(height);
});
})

http://jsfiddle.net/LvsYc/15487/