Asyncfileupload文件预览不显示

Question

我在更新面板中有一个Ajax异步文件上传控件。我的上传效果很好，但是上传完成后，我需要查看上传的图片。但这不起作用是我所做的

function UploadComplete(sender, args) {
        var filename = args.get_fileName();
        var contentType = args.get_contentType();
        if (contentType.indexOf('image') == -1) {
            document.getElementById('<%=lblStatus.ClientID%>').innerText = "Uploaded file must be an Image!"+ "<span style='color:red;'>" + args.get_errorMessage() + "</span>";
            document.getElementById('<%=AsyncFileUpload1.ClientID%>').text.style.backgroundColor = "Red";
        }
        else {
            var text = "" + filename + "      |      " + args.get_length() + " bytes"+"Uploaded Succesfully";
            document.getElementById('<%=lblStatus.ClientID%>').innerText = text;
              $get("imageView1").src = "./~/" + filename;
        }
    }

AspCode：

<ajaxToolkit:AsyncFileUpload ID="AsyncFileUpload1" Width="400px" runat="server"    
        OnClientUploadError="uploadError"    
        OnClientUploadStarted="StartUpload"  
        OnClientUploadComplete="UploadComplete"  
        CompleteBackColor="Lime" UploaderStyle="Modern"    
        ErrorBackColor="Red" ClientIDMode="AutoID"    
        ThrobberID="Throbber"    
        UploadingBackColor="#66CCFF" 
            onuploadedcomplete="AsyncFileUpload1_UploadedComplete" />

 <asp:Label ID="Throbber" runat="server" Style="display: none">
 <asp:Image runat="server" ID="imgPreview" ImageUrl="~/Images/uploading.gif" />
        </asp:Label>
        <img runat="server" id="imageView1"/>
 <asp:Label ID="lblStatus" runat="server" Style="font-family: Arial; font-size: small;"></asp:Label>

Answer 1

您可以使用OnUploadedComplete事件显示图像。

<ajaxToolkit:AsyncFileUpload ID="AsyncFileUpload1" Width="400px" runat="server" OnUploadedComplete="ProcessUpload"

protected void ProcessUpload(object sender, AjaxControlToolkit.AsyncFileUploadEventArgs e)
{
string fileName = Server.MapPath("./") + "image.jpg";
AsyncFileUpload1.SaveAs(fileName);

ScriptManager.RegisterClientScriptBlock(AsyncFileUpload1, AsyncFileUpload1.GetType(), "img",
    "top.document.getElementById('imgUpload').src='image.jpg';", 
    true);
}

有关如何显示预览的详细信息，请看以下示例：具有AsyncFileUpload控件的ASP.NET中的AJAX文件上传