Question

我有ajax AsyncFileUpload控件和图像控件。当通过上传器选择图像时，我在图像控件中显示它。我有处理程序：

public class Handler : IHttpHandler, IRequiresSessionState
{
public void ProcessRequest(HttpContext context)
{
    context.Response.Clear();
    if (context.Request.QueryString.Count != 0)
    {
        //Get the stored image and write in the response.
        var storedImage = context.Session["STORED_IMAGE"] as byte[];
        if (storedImage != null)
        {
            Image image = GetImage(storedImage);
            if (image != null)
            {
                context.Response.ContentType = "image/jpeg";
                image.Save(context.Response.OutputStream, ImageFormat.Jpeg);
            }
        }
    }
}
private Image GetImage(byte[] storedImage)
{
    var stream = new MemoryStream(storedImage);
    return Image.FromStream(stream);
}
public bool IsReusable
{
    get
    {
        return false;
    }
}
}

在Aspx页面中：

    <asp:UpdatePanel ID="UpdatePanel1" UpdateMode="Always" runat="server">
            <ContentTemplate>
                <div class="FakeFileUpload">
                    <div class="FakeFileUploadDiv">
                        <asp:Image ID="imgPhoto" runat="server" ImageUrl="download.jpeg" alt="Employee Photo"
                            Height="150px" Width="150px" />
                    </div>
                    <cc11:AsyncFileUpload ID="AsyncFileUpload1" runat="server" ThrobberID="loader"
                        CssClass="FileUploadClass" OnClientUploadComplete="OnClientAsyncFileUploadComplete"
                        OnUploadedComplete="AsyncFileUpload1_UploadedComplete" Width="150" />
                    <asp:Image ID="loader" runat="server" />
                </div>
            </ContentTemplate>
        </asp:UpdatePanel>

脚本：

 <script type="text/javascript">
        function getRandomNumber() {
            var randomnumber = Math.random(10000);
            return randomnumber;
        }
        function OnClientAsyncFileUploadComplete(sender, args) {
            var handlerPage = '<%= Page.ResolveClientUrl("Handler.ashx")%>';
            var queryString = '?randomno=' + getRandomNumber();
            var src = handlerPage + queryString;
            var clientId = '<%=imgPhoto.ClientID %>';
            document.getElementById(clientId).setAttribute("src", src);
        }
    </script>

这一切都运行正常，但是当我点击任何其他按钮时，图像控件中的内容将丢失。我希望当回发发生时，该图像仍然存在。

我从以下代码获得了代码： http://www.harinadh.com/2012/07/profile-picture-using-asyncfileupload.html

任何人都可以帮我这样做吗？

提前致谢。

回发后保留图像内容

0 个答案: