我正在通过ajax将Image base64数据传递给我的php函数，但是对于大尺寸图像，Ajax不会发布数据。但是，相同的代码对于小图像非常适用。

srcdata=data:image/jpeg;base64,/9j/4SxvRXhpZgAASUkqAAgAAAANAAABBAABAAAAwAwAAAEBBAABAAAALAcAAA8BAgAIAAAAqgAAABABAgARAAAAsgAAABIBAwABAAAABgAAABoBBQABAAAAxAAAABsBBQABAAAAzAAAACgBAwABAAAAAgAAADEBAgAMAAAA1AAAADIBAgAUAAAA4AAAABMCAwABAAAAAQAAAGmHBAABAAAA9AAAACWIBAABAAAA3gkAAPAJAABTQU1TVU5HAFNBTVNVTkctU0dILUk1MzcAAEgAAAABAAAASAAAAAEAAABJNTM3VUNVQ05DOQAyMDE0OjA2OjIyIDEwOjE3OjEwACEAmoIFAAEAAACGAgAAnYIFAAEAAACOAgAAIogDAAEAAAADAAAAJ4gDAAEAAAB9AAAAAJAHAAQAAAAwMjIwA5ACABQAAACWAgAABJACABQAAACqAgAAAZEHAAQAAAABAgMAAZIKAAEAAAC 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 giAABS0pLSmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGVXEABVVxAAVVcQAFmWAACWZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZVcQAFVXEABVVxAAVVcQAFVXEABVVxAAVVcQAFVXEABZlwAAlmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGVXEABVVxAAVVcQAFVXEABVVxAAVVcQAFVXEABVVxAAWZcAAJZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABlVxAAVVcQAFVXEABVVxAAVVcQAFVXEABVVxAAVVcQAFmXAACWZxAAZmcQAGZnEABmZxAAZmcQAGZnEABplwAAlVcQAFVXEABVVxAAVVcQAFVXEABVVxAAVVcQAFVXEABZlwAAlmcQAGZnEABmZxAAZmcQAGZnEABmZxAAaZcAAJVXEABVVxAAVVcQAFVXEABVVxAAVVcQAFVXEABVVxAAWZcAAJZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGmXAACVVxAAVVcQAFVXEABVVxAAVVcQAFVXEABVVxAAVVcQAFmXAACWZxAAZmcQAGZnEABmZxAAZmcQAGZnEABplwAAlVcQAFVXEABVVxAAVVcQAFVXEABVVxAAVVcQAFVXEABZlwAAlmcQAGZnEABmZxAAZmcQAGZnEABmZxAAaZcAAJVXEABVVxAAVVcQAFVXEABVVxAAVVcQAFVXEABVVxAAWZcAAJmXAACWZxAAZmcQAGZnEABmZxAAZmcQAGmXAACVVxAAVVcQAFVXEABVVxAAVVcQAFVXEABVVxAAVVcQAFmWAACZlwAAlmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGVXEABVVxAAVVcQAFVXEABVVxAAVVcQAFVXEABZlgAAmZcAAJZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAYRUAABmXAACWZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZmcQAGZnEABmZxAAZLSktKAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAASLAAAf/8AACRQAABVo8AAf/3AAB25wABAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAATv8AAf/2AACFNwABTv8AAf/2AACFNwABT5QAAf/2AACFXgABT5QAAf/2AACFXgABAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAEtKABYAAEZBRkEAHIjEAAEAHOcsAAEAMRzRAAIARn5sAAIAWwYuAAMAcAgFAAMAmtFlAAEAmnjxAAEAmpN5AAEAjPohAAEAfnrCAAIAcNwgAAIAYjlTAAMAVDJzAAMARuH8AAIAVOH8AAIBgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAABgQAAAAAAAAAARkFGQQADAD8AAwArAABGQUZBABg8AAAAPAAAAFMwOFFFTENHQzAxAAcAAQAHAAQAAAAwMTAwAgAEAAEAAAAAIAEADAAEAAEAAAAAAAAAEAAFAAEAAABaAAAAQAAEAAEAAAAAAAAAUAAEAAEAAAABAAAAAAEDAAEAAAAAAAAAAAAAAAAAAAAAAAAAAgABAAIABAAAAFI5OAACAAcABAAAADAxMDAAAAAAAQAAAAEABAAAAAICAAAAAAAACQAAAQQAAQAAAAABAAABAQQAAQAAAJAAAAADAQMAAQAAAAYAAAASAQMAAQAAAAYAAAAaAQUAAQA `

数据太大，因此部分发布了，

ajax

count = 1;
name='test'
jQuery.ajax({
    url:"/createImage.php",
    data:{img_data:srcdata,img_id:count,name:name},
    type:"POST",
    contentType:"application/x-www-form-urlencoded",
    success:function(result)
    {
        alert(result);
    }
});

PHP

print_r($_POST); // is empty when logging..

当我尝试获取php中的发布数据时，我越来越空了。使用base64时，ajax不发送数据的原因可能是什么？