Javascript 使用javascript检查图像是否存在
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Checking if image does exists using javascript
提问by X10nD
Possible Duplicate:
Check if image exists with given url using jquery
Change image source if file exists
I am throwing the value of an image path from a textbox into boxvalue and want to validate if the image exist using javascript.
我将文本框中的图像路径的值扔到 boxvalue 中，并想使用 javascript 验证图像是否存在。
var boxvalue = $('#UrlQueueBox').val();
I browsed stackoverflow and found the below to get the image width/height, but don't want to use this.
我浏览了 stackoverflow 并找到了以下内容来获取图像宽度/高度，但不想使用它。
var img = document.getElementById('imageid');
How can an I validate if it is really an image from the image path?
我如何验证它是否真的是来自图像路径的图像？
回答by maerics
// The "callback" argument is called with either true or false
// depending on whether the image at "url" exists or not.
function imageExists(url, callback) {
var img = new Image();
img.onload = function() { callback(true); };
img.onerror = function() { callback(false); };
img.src = url;
}
// Sample usage
var imageUrl = 'http://www.google.com/images/srpr/nav_logo14.png';
imageExists(imageUrl, function(exists) {
console.log('RESULT: url=' + imageUrl + ', exists=' + exists);
});
回答by Felipe Oriani
You can create a function and check the completeproperty.
您可以创建一个函数并检查complete属性。
function ImageExists(selector) {
var imageFound = $(selector);
if (!imageFound.get(0).complete) {
return false;
}
else if (imageFound.height() === 0) {
return false;
}
return true;
}
and call this funciton
并调用这个函数
var exists = ImageExists('#UrlQueueBox');
Same function with the url instead of a selector as parameter (your case):
使用 url 而不是选择器作为参数的相同功能（您的情况）：
function imageExists(url){
var image = new Image();
image.src = url;
if (!image.complete) {
return false;
}
else if (image.height === 0) {
return false;
}
return true;
}
