Question

我使用asp.net和c＃创建了学生详细信息。

我最近添加了图片字段，当我编辑细节，并编辑一些没有图像的字段（必要时编辑），然后提交..它显示＆＃34;请上传您的图像＆＃34;警惕。

所以我需要检查图像文件夹和文件上传中的图像是否为空。

这是我的代码：

代码隐藏：

protected void btnsub_Click(object sender, EventArgs e)
        {
            SqlConnection con = Connection.DBconnection();
            if (Textid.Text.Trim().Length > 0)
            {
                SqlCommand com = new SqlCommand("StoredProcedure3", con);
                com.CommandType = CommandType.StoredProcedure;
                com.Parameters.AddWithValue("@id", Textid.Text.Trim());
                com.Parameters.AddWithValue("@Name", Textusername.Text.Trim());
                com.Parameters.AddWithValue("@Class", Textclass.Text.Trim());
                com.Parameters.AddWithValue("@Section", Textsection.Text.Trim());
                com.Parameters.AddWithValue("@Address", Textaddress.Text.Trim());
                try
                {
                    string filename = string.Empty;
                    if (fileupload.PostedFile.FileName.Length > 0)
                    {
                        filename = Path.GetFileName(fileupload.PostedFile.FileName);
                        fileupload.SaveAs(Server.MapPath("~/Images/" + filename));
                    }
                    com.Parameters.AddWithValue("@Image",(filename.Length>0)? "Images/" + filename:string.Empty);
                    com.ExecuteNonQuery();                    
                }
                catch (Exception ex)
                {
                    btnsub.Text = ex.Message;
                }
                Response.Redirect("studententry.aspx");
            }
            else
            {
                SqlCommand com = new SqlCommand("StoredProcedure1", con);
                com.CommandType = CommandType.StoredProcedure;
                com.Parameters.AddWithValue("@Name", Textusername.Text.Trim());
                com.Parameters.AddWithValue("@Class", Textclass.Text.Trim());
                com.Parameters.AddWithValue("@Section", Textsection.Text.Trim());
                com.Parameters.AddWithValue("@Address", Textaddress.Text.Trim());
                try
                {
                    string filename = string.Empty;
                    if (fileupload.PostedFile.FileName.Length > 1)
                    {
                        filename = Path.GetFileName(fileupload.PostedFile.FileName);
                        fileupload.SaveAs(Server.MapPath("~/Images/" + filename));
                    }
                    com.Parameters.AddWithValue("@Image",(filename.Length>0)? "Images/" + filename:string.Empty);
                    com.ExecuteNonQuery();                    
                }
                catch (Exception ex)
                {
                    btnsub.Text = ex.Message;
                }
                Response.Redirect("studententry.aspx");
            }
        }
        protected void btnrst_Click(object sender, EventArgs e)
        {
            Textid.Text = string.Empty;
            Textusername.Text = string.Empty;
            Textclass.Text = string.Empty;
            Textsection.Text = string.Empty;
            Textaddress.Text = string.Empty;
        }
        protected void GridView1_RowCommand(object sender, GridViewCommandEventArgs e)
        {
            SqlConnection con = Connection.DBconnection();

            if (e.CommandName == "EditRow")
            {

                GridViewRow gr = (GridViewRow)((Button)e.CommandSource).NamingContainer;
                int index = gr.RowIndex; 
                hiddenfield.Value = index.ToString(); 
                Textid.Text = gr.Cells[0].Text;
                Textusername.Text = gr.Cells[1].Text;
                Textclass.Text = gr.Cells[2].Text;
                Textsection.Text = gr.Cells[3].Text;
                Textaddress.Text = gr.Cells[4].Text;
                Image1.ImageUrl = ((System.Web.UI.WebControls.Image)gr.Cells[5].Controls[0]).ImageUrl;               
            }
            else if (e.CommandName == "Deleterow")
            {
                SqlCommand com = new SqlCommand("StoredProcedure4", con);
                com.CommandType = CommandType.StoredProcedure;
                com.Parameters.AddWithValue("@ID", Convert.ToInt32(e.CommandArgument));
                var id = Int32.Parse(e.CommandArgument.ToString());                
                com.ExecuteNonQuery();
                Response.Redirect("studententry.aspx");
            }
        }
        protected void GridView1_SelectedIndexChanged(Object sender, EventArgs e)
        {
            int index = GridView1.SelectedIndex;
            hiddenfield.Value = index.ToString();
        }

ASPX：

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">

    <center><div><h4>Student Registration</h4></div></center>
<div class="tblalign">
    <table style="width: 100%;">
    <tr>
    <td><asp:HiddenField ID="hiddenfield" runat="server" /> 
    <asp:TextBox ID="Textid" runat="server" Visible="false"></asp:TextBox>
    </td>

    </tr>
        <tr>
            <td>
                <asp:Label ID="Label1" runat="server" Text="Name"></asp:Label>

            </td>
            <td>
                &nbsp;
            </td>
            <td>
                <asp:TextBox ID="Textusername" runat="server"></asp:TextBox>

            </td>
        </tr>
        <tr>
            <td>
                <asp:Label ID="Label2" runat="server" Text="Class"></asp:Label>

            </td>
            <td>
                &nbsp;
            </td>
            <td>
                <asp:TextBox ID="Textclass" runat="server"></asp:TextBox>

            </td>
        </tr>
        <tr>
            <td>
                <asp:Label ID="Label3" runat="server" Text="Section"></asp:Label>

            </td>
            <td>
                &nbsp;
            </td>
            <td>
                <asp:TextBox ID="Textsection" runat="server"></asp:TextBox>
            </td>
        </tr>
        <tr>
        <td>
            <asp:Label ID="Label5" runat="server" Text="Address"></asp:Label>
        </td>

        <td>
            &nbsp;
        </td>
        <td>
            <asp:TextBox ID="Textaddress" runat="server"></asp:TextBox>
        </td>
        </tr>
        <tr>
            <td>
            <asp:Label ID="Label4" runat="server" Text="Image"></asp:Label>
            </td>
            <td>
            &nbsp;
        </td>
        <td>
            <asp:Image ID="Image1" runat="server" ControlStyle-Width="50" ControlStyle-Height = "50"  />

        </td>
        <td>
        <asp:FileUpload ID="fileupload" runat="server" />  
         </td>
        </tr>
        <tr>
        <td>
            <asp:Button ID="btnsub" runat="server" Text="Submit" OnClick="btnsub_Click" OnClientClick="return register();" />
            <asp:Button ID="btnrst" runat="server" Text="Reset" OnClick="btnrst_Click" />
        </td>
        <td>
        </td>            
        <td>            
        </td>
    </tr>

</table></div>
<br />
<br />
<center><div><h4>Student Records</h4></div></center><br /> <br />
    <asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" 
        DataKeyNames="ID" DataSourceID="SqlDataSource1" 
        OnRowCommand="GridView1_RowCommand" 
        EnablePersistedSelection="True" BackColor="White" 
        OnSelectedIndexChanged="GridView1_SelectedIndexChanged">
        <Columns>
            <asp:BoundField DataField="ID" HeaderText="ID" InsertVisible="False" 
                ReadOnly="True" SortExpression="ID" />
            <asp:BoundField DataField="Name" HeaderText="Name" SortExpression="Name" />
            <asp:BoundField DataField="Class" HeaderText="Class" SortExpression="Class" />
            <asp:BoundField DataField="Section" HeaderText="Section" 
                SortExpression="Section" />
            <asp:BoundField DataField="Address" HeaderText="Address" 
                SortExpression="Address" />
                <asp:ImageField DataImageUrlField="Image" HeaderText="Image" ControlStyle-Width="50" ControlStyle-Height = "50">                
                </asp:ImageField> 
            <asp:TemplateField HeaderText="Edit">
               <ItemTemplate>
                 <asp:Button runat="server" ID="btnedit" Text="Edit" CommandName="EditRow"></asp:Button>                    
               </ItemTemplate>
                <ControlStyle BorderColor="#CCFF66" />
          </asp:TemplateField>
          <asp:TemplateField HeaderText="Delete">
          <ItemTemplate>
                 <asp:Button runat="server" ID="btndelete" Text="Delete" CommandArgument='<%# Eval("Id") %>' CommandName="Deleterow"></asp:Button>                    
               </ItemTemplate>
          </asp:TemplateField>            
        </Columns>
        <SelectedRowStyle BackColor="#FF66FF" />
    </asp:GridView>
        <asp:SqlDataSource ID="SqlDataSource1" runat="server" 
        ConnectionString="<%$ ConnectionStrings:ConnectionString %>" 
        SelectCommand="StoredProcedure2"          
        SelectCommandType="StoredProcedure">
            <DeleteParameters>
                <asp:Parameter Name="ID" />
                <asp:Parameter Name="Name" />
                <asp:Parameter Name="Class" />
                <asp:Parameter Name="Section" />
                <asp:Parameter Name="Image" />
            </DeleteParameters>
            <UpdateParameters>
                <asp:Parameter Name="ID" />
                <asp:Parameter Name="Name" />
                <asp:Parameter Name="Class" />
                <asp:Parameter Name="Section" />
                <asp:Parameter Name="Image" />
            </UpdateParameters>
    </asp:SqlDataSource>
</asp:Content>

OUTPUT

我认为在editrow命令中，我需要检查条件。其实我是.net。

的新手

所以任何人都可以帮我解决这个问题。

任何帮助都将受到高度赞赏。

谢谢，

Answer 1

要检查特定文件，请使用File.Exists(path)，它将返回一个布尔值，指示路径中的文件是否存在。

System.IO.File.Exists(path)

由于您的代码是同步的，因此可以在将图像上传到文件夹后检查是否立即加载图像。例如：

try
  {
     string filename = string.Empty;
     if (fileupload.PostedFile.FileName.Length > 0)
        {
           filename = Path.GetFileName(fileupload.PostedFile.FileName);
           fileupload.SaveAs(Server.MapPath("~/Images/" + filename));
        }     
     string imgAddress = Path.GetFileName(fileupload.PostedFile.FileName);   
     //check whether your image is created:
     bool isExist=System.IO.File.Exists(imgAddress);
     com.Parameters.AddWithValue("@Image",(filename.Length>0)? "Images/" + filename:string.Empty);
     com.ExecuteNonQuery();                    
  }
catch (Exception ex)
{
   btnsub.Text = ex.Message;
}

Answer 2

filename = Path.GetFileName(fileupload.PostedFile.FileName);
var fullPath="~/Images/" + filename;


if (System.IO.File.Exists(Server.MapPath(fullPath)))
{
    // file exist
}
else
{
   // file not exist
}

如何在c＃中检查文件夹中的文件上传或图像

2 个答案: