ASP.NET WEB开发，实现上传图片

protected void btnUp_Click(object sender, EventArgs e)
    {
       
            Boolean fileOK = false;
            String path = Server.MapPath("~/UploadedImages/");
            if (fileUpLoad.HasFile)
            {
                String fileExtension =
                    System.IO.Path.GetExtension(fileUpLoad.FileName).ToLower();
                String[] allowedExtensions = { ".gif", ".png", ".jpeg", ".jpg" };
                for (int i = 0; i < allowedExtensions.Length; i++)
                {
                    if (fileExtension == allowedExtensions[i])
                    {
                        fileOK = true;
                    }
                }
            }

            if (fileOK)
            {
                try
                {
                    fileUpLoad.PostedFile.SaveAs(path
                        + fileUpLoad.FileName);
                    Label1.Text = "File uploaded!";
                }
                catch (Exception ex)
                {
                    Label1.Text = "File could not be uploaded." + ex.ToString();
                }
            }
            else
            {
                Label1.Text = "Cannot accept files of this type.";
            }
     
        
    }

设计界面的代码如下

 <form id="form1" runat="server">
    <div>
    
        <asp:FileUpload ID="fileUpLoad" runat="server" />
        <asp:Label ID="Label1" runat="server" Text="Label"></asp:Label>
        <p>
        <asp:Button ID="btnUp"
            runat="server" Text="上传" onclick="btnUp_Click" />
            </p>
    </div>
    </form>

默认限制上传的大小为4M=4096

在web.Config中进行设置，代码如下在<System.Web></System.Web>：

  <httpRuntime maxRequestLength="4096" executionTimeout="100"/>