swfUpload上传图片

我使用的是swfupload2.0版本。
需要注意的几个属性：
file_post_name，相当于用普通的文件域上传文件时的name属性，服务器端接收页面通过该名称来获取上传的文件。
upload_url，处理上传文件的服务器端页面的url地址。
button_placeholder_id，指定一个dom元素的id,该dom元素在swfupload实例化后会被Flash按钮代替，</span>
这个dom元素相当于一个占位符。
button_action:SWFUpload.BUTTON_ACTION.SELECT_FILE,//设置一次只能选择一个文件
当属性值为SWFUpload.BUTTON_ACTION.SELECT_FILES时，设置可以选择多个文件

//上传按钮显示的位置
<button id="spanButtonPlaceholder1"></button>

<script type="text/javascript">
    var swfu;

    SWFUpload.onload = function () {
        var settings = {
            file_post_name : "file",flash_url : "/swfupload2/swfupload.swf",upload_url:'Uploadimage',//后台处理图片的url
            post_params: {
                "PHPSESSID" : "<?php echo session_id();?>"
            },// File Upload Settings
            file_size_limit: "1 MB",file_types: "*.jpg;*.jpeg;*.png;",file_types_description : "All Files",file_upload_limit : 1,file_queue_limit : 0,// Event Handler Settings (all my handlers are in the Handler.js file)
            file_dialog_start_handler : fileDialogStart,file_queued_handler : fileQueued,file_queue_error_handler : fileQueueError,file_dialog_complete_handler : fileDialogComplete,upload_start_handler : uploadStart,upload_progress_handler : uploadProgress,upload_error_handler : uploadError,upload_success_handler : uploadSuccess,upload_complete_handler : uploadComplete,//上传按钮的设置
            button_image_url : "../images/icon49.gif",button_placeholder_id : "spanButtonPlaceholder1",//按钮显示的位置
            button_width: "120",button_height: "36",custom_settings : {
                progressTarget : "fsUploadProgress1",cancelButtonId : "btnCancel1",imgInput: "img"
            },// Debug Settings
            debug: false
        };

        swfu = new SWFUpload(settings);
    }
    
    //图片上传成功的处理函数
    function uploadSuccess(file,serverData) {
        try {
            var data = eval("(" + serverData + ")");
            
        } catch (ex) {
            this.debug(ex);
        }
    }

</script>