Ext.Net.FileUploadField.OnBeforeClientInit C# (CSharp) Method

        protected override void OnBeforeClientInit(Observable sender)
        {
            if (this.AutoPostBack)
            {
                //this.On("fileselected", new JFunction(this.PostBackFunction));
                this.CustomConfig.Add(new ConfigItem("postback", JSON.Serialize(new { eventName = "fileselected", fn = new JFunction(this.PostBackFunction) }), ParameterMode.Raw));
            }
        }