Uplaod图像上使用asp文件上传4 MB？文件上传、图像、Uplaod、MB
我使用的是asp文件上传由我上传按钮上的图像点击。每当它崩溃。如果我在配置了maxRequestLength的定义大小，我上传图片超过4 MB 然后，如果我超过文件大小重新它crashes.Is能够限制用户，并显示一个声明消息，如果一个巨大的文件被上载。我的内涵是让用户知道该文件是巨大的。
I am using a asp file uploader by which i am uploading an image on a button click .whenever i am uploading an image over 4 mb it crashes .if i define a size in config for maxrequestlength then if i exceed the file size again it crashes.Is it possible to restrict user and show a disclaimer message if a huge file is uploaded . My intension is to let the user know that file is huge .
aspx页面
<tr>
<td align="center" class="title" colspan="2">
Image Upload
</td>
</tr>
<tr>
<td align="center" colspan="2">
<asp:Label ID="lblImageDisclaimer" runat="server" Text="Please upload an image file less than 3MB in size"
Font-Bold="true" ForeColor="Highlight"></asp:Label>
</td>
</tr>
<tr>
<td align="center" colspan="2">
<asp:DropDownList ID="ddlImageType" runat="server" AutoPostBack="false" OnSelectedIndexChanged="ddlImageType_SelectedIndexChanged">
</asp:DropDownList>
</td>
</tr>
<tr>
<td align="center" colspan="2" id="tdUpload" runat="server">
<asp:Label ID="lblImage1" runat="server" Text="Upload images : " Font-Bold="true"></asp:Label>
<asp:FileUpload ID="fileUploader" runat="server" /><asp:Button ID="btnUpload" CssClass="button"
runat="server" Text="Upload" OnClick="btnUpload_Click" OnClientClick="javascript:return validateFile();" />
<asp:Label ID="lblMessage" runat="server" Text="" CssClass="errorText"></asp:Label>
</td>
</tr>
<tr>
<td id="Td2" runat="server" align="center" colspan="1">
<asp:Label ID="Label1" runat="server" Text="SCREENSHOT 1" Font-Bold="true"></asp:Label>
</td>
<td id="Td3" runat="server" align="center" colspan="1">
<asp:Label ID="Label2" runat="server" Text="SCREENSHOT 2" Font-Bold="true"></asp:Label>
</td>
</tr>
<tr>
<td id="imgHolder" runat="server" align="center" colspan="1">
<div style="border: SOLID 1px BLACK; width: 575px; height: 250px; overflow: auto;">
<%--<asp:Image ID="imgPreview" runat="server" ImageUrl="~/FIRE/ImageHandler.ashx?id=1&imageNo=2" />--%>
<asp:Image ID="imgPreview" runat="server" />
</div>
</td>
<td id="imgHolder2" runat="server" align="center" colspan="1">
<div style="border: SOLID 1px BLACK; width: 575px; height: 250px; overflow: auto;">
<%--<asp:Image ID="imgPreview" runat="server" ImageUrl="~/FIRE/ImageHandler.ashx?id=1&imageNo=2" />--%>
<asp:Image ID="imgPreview2" runat="server" />
</div>
</td>
</tr>
<tr>
<td id="tdDelete1" align="left" style="width: 100%; padding-left: 15px;" colspan="1">
<asp:Button ID="btnDelete1" runat="server" Text="Delete" CssClass="button" OnClick="btnDelete_Click"
ToolTip="Click to Delete" OnClientClick="javascript:return confirm('Are you sure you want to delete this image?');" />
</td>
<td id="tdDelete2" align="left" style="width: 100%" colspan="1">
<asp:Button ID="btnDelete2" runat="server" Text="Delete" CssClass="button" OnClick="btnDelete_Click"
ToolTip="Click to Delete" OnClientClick="javascript:return confirm('Are you sure you want to delete this image?');" />
</td>
</tr>
的.cs页面事件。 保护无效btnUpload_Click（对象发件人，EventArgs的） { 尝试 { //hfCurrentId.Value =工作项ID：+ hfWorkItemID.Value; 如果（fileUploader.HasFile） { 如果（fileUploader.PostedFile.ContentType.Contains（图像）及和放大器; fileUploader.PostedFile.ContentLength＆LT; = 3145728） {
.cs page events. protected void btnUpload_Click(object sender, EventArgs e) { try { //hfCurrentId.Value = "Work item id: " + hfWorkItemID.Value; if (fileUploader.HasFile) { if (fileUploader.PostedFile.ContentType.Contains("image") && fileUploader.PostedFile.ContentLength <= 3145728) {
if (ddlImageType.SelectedValue == "1")
{
Session["FileBytes"] = fileUploader.FileBytes;
hfImage1Byte.Value = Convert.ToBase64String(fileUploader.FileBytes);
imgPreview.ImageUrl = "~/Handlers/ImageHandler.ashx?workItemId=" + workItemId
+ "&imageTypeId=" + ddlImageType.SelectedValue;
}
else
{
Session["FileBytes2"] = fileUploader.FileBytes;
hfImage2Byte.Value = Convert.ToBase64String(fileUploader.FileBytes);
imgPreview2.ImageUrl = "~/Handlers/ImageHandler.ashx?workItemId=" + workItemId
+ "&imageTypeId=" + ddlImageType.SelectedValue;
}
}
else
{
lblMessage.Text = Constants.ImageFileError;
}
}
else
{
lblMessage.Text = Constants.FileError;
}
//lblHeader.Text = hfCurrentId.Value;
//upPanel1.Update();
}
catch (System.Exception ex)
{
//DisplayError(ex);
Session["ExceptionDetails"] = ex;
Response.Redirect(Constants.FIREErrorDetails);
}
}
在这里，我感到3145728限制大小 和处理它的客户端大小
Here i am limiting the size by 3145728 and handling it in client size
function validateFile() {
var strFileName = document.getElementById('<%=fileUploader.ClientID %>').value;
var strExtName = strFileName.substring(strFileName.lastIndexOf('.')).toLowerCase();
var objFSO = new ActiveXObject("Scripting.FileSystemObject");
var e = objFSO.getFile(strFileName);
var fileSize = e.size;
//file size limit for 3mb
if (fileSize > 3145728) {
alert("Maximum size of uploaded file should be less than 3 MB.");
return false;
}
else
return true;
}
有没有其他的方式，以避免
is there any other way to avoid
var objFSO = new ActiveXObject("Scripting.FileSystemObject");
我不能使用的ActiveXObject根据一些客户的问题
I can't use ActiveXObject as per some client issue
推荐答案
假如你不使用HTML5。假如你不使用所建议的卡尔定制/第三方组件。
Assuming that you are not using HTML5. Assuming you are not using custom/third-party components as suggested by Karl.
（1）您将需要首先限制上传大小在web.config中的IIS：
(1) You will need to first limit the upload size in web.config for IIS:
<system.webServer>
<security>
<requestFiltering>
<requestLimits maxAllowedContentLength="YOUR_MAX_ALLOWED_SIZE IN BYTES"/>
</requestFiltering>
</security>
</system.webServer>
（2）确保值匹配的httpRuntime的ASP.Net：
(2) Make sure the values are matching in httpRuntime for ASP.Net:
<httpRuntime executionTimeout="SECONDS" maxRequestLength="YOUR_MAX_ALLOWED_SIZE IN KB"/>
（3）检查大小超过服务器端code和适当的告知用户：
(3) Check if the size exceeds in your server-side code and suitably inform the user:
if (fileUpload.PostedFile.ContentLength > (YOUR_MAX_ALLOWED_SIZE - n)) {
// where "n" is arbitrary number to intercept uploads before IIS kicks it
// you display limit to users as (YOUR_MAX_ALLOWED_SIZE - n)
// inform problem to the user here
}
您不能，除非你使用HTML5文件API在客户端进行检查。因此，用户必须等待，直到整个文件被上载，然后将其刷爆。因此，精心设置YOUR_MAX_ALLOWED_SIZE。
You cannot check it at the client-side unless you are using HTML5 File API. So, the user has to wait until the entire file is uploaded and then it is maxed out. Hence, set your YOUR_MAX_ALLOWED_SIZE carefully.
更新
正如你看到的，这是困难的，如果在大小超过限制来抓。有几个解决方法：
As you see, it is difficult to catch if the size exceeds the limit. There a few workarounds:
设置自定义错误：
Set up custom errors:
在 system.webServer 设置 httpErrors 部分：
请参阅由Marcus在这里接受的答案：Display当文件上传超出允许大小的ASP.NET MVC 自定义错误页
See the accepted answer by Marcus here: Display custom error page when file upload exceeds allowed size in ASP.NET MVC
