我是网络开发的新手，现在我正在网站上工作。我在ASP.Net（前端）Web表单上有一个Save按钮有问题（后端在C＃中）。该按钮用于将文本框中输入的数据保存到数据库中。
第一次单击“保存”按钮时，页面只是“重新加载”并清除文本框，SQL Server数据库中没有任何内容保存（dbo连接）。然后，当我在文本框中重新输入信息后第二次单击相同的“保存”按钮时，它实际上保存到数据库并返回主菜单页面（如预期的那样）。如果我尝试重新输入不同的信息，保存按钮将正常工作。
当用户登录并导航到他输入数据并保存数据的页面时，就会出现问题。它永远不会第一次工作。
不幸的是，由于机密目的，我必须省略并重命名某些文件路径/目录和表名！
这是我的Asp.NET代码：
<%@ Page Language="C#" debug="True" Inherits="Default" src="Default.cs" AutoEventWireup ="true"%>
<%@ Register TagPrefix="ob" TagName="ComboTree" Src="/obout/Combotree/ComboTree.ascx" %>
<%@ Reference Control="/obout/Combotree/ComboTree.ascx" %>
<HTML>
<HEAD>
<!-- #INCLUDE VIRTUAL="/.../" -->
</HEAD>
<BODY >
<FORM runat="server">
<BASEFONT face="Arial, Helvetica, Sans Serif" color=black size=2>
<TABLE height="100%" cellSpacing=0 cellPadding=0 width="780" align=Center border=0>
<!-- #INCLUDE VIRTUAL="/.../" -->
<TR VALIGN="top">
<!-- #INCLUDE VIRTUAL="/.../" -->
`enter code here`<TD vAlign=top width="100%" HEIGHT="100%">
<TABLE cellSpacing=0 cellPadding=0 width="100%" border=0 HEIGHT="100%">
<!-- #INCLUDE VIRTUAL="/.../" -->
<TR>
<!-- #INCLUDE VIRTUAL="/.../" -->
<TD vAlign=top align=left >
<!--- START YOUR CODE HERE!!!!! --->
<script>
function disableListItems(checkBoxListId, disable)
{
// Get the checkboxlist object.
ctr = 0;
while(1 == 1)
{
checkbox = document.getElementById(checkBoxListId + "_" + ctr);
if(checkbox == null)
{
return;
}
checkbox.checked = true;
checkbox.disabled = disable;
ctr++;
}
}
function checkForm()
{
var errMsg = "";
if(isBlank(document.getElementById("tbName").value))
{
errMsg += "\n-Folder Name";
}
if(errMsg!="")
{
alert("The following fields cannot be left blank." + errMsg);
return false;
}
return true;
}
</script>
<font Class="heading">File Library - <ASP:Label ID="lbTitle" RunAt="Server"/> Folder</font>
<INPUT Type="Hidden" ID="hdFolderID" RunAt="Server"/>
<INPUT Type="Hidden" ID="hdParentFolderID" RunAt="Server"/>
<TABLE CellPadding="4" CellSpacing="0" Width="100%" >
<TR>
<TD ColSpan="2" Class="spreadsheet_line"> </TD>
</TR>
<TR>
<TD Class="Spreadsheet"><B>Name</B></TD>
<TD Class="Spreadsheet" Width="100%"><ASP:TextBox ID="tbName" Columns="34" RunAt="Server"/></TD>
</TR>
<TR VAlign="Top" Visible="False" RunAt="Server">
<TD Class="Spreadsheet" NOWRAP><B>Description</B></TD>
<TD Class="Spreadsheet"><ASP:TextBox ID="tbDescription" TextMode="Multiline" Cols="25" Rows="5" RunAt="Server"/></TD>
</TR>
<TR>
<TD Class="Spreadsheet"><B>Active?</B></TD>
<TD Class="Spreadsheet"><ASP:CheckBox ID="cbActive" RunAt="Server"/></TD>
</TR>
<TR Visible="False" RunAt="Server">
<TD Class="Spreadsheet"><B>Folder</B></TD>
<TD Class="Spreadsheet"><ob:ComboTree id="ctFolders" runat="server"/></TD>
</TR>
<TR VAlign="Top" ID="trLicensees" RunAt="Server">
<TD Class="Spreadsheet"><B>Departments</B></TD>
<TD Class="Spreadsheet">
<ASP:DropDownList ID="ddLicensee" DataTextField="Name" DataValueField="DepartmentId" RunAt="Server"/>
<ASP:CheckBox ID="cbAll" Text="All" RunAt="Server"/>
<div style="text-align: left; width: 30%; margin-left:-3px">
<ASP:CheckBoxList ID="cblLicensees" DataTextField="Name" DataValueField="DepartmentId" style="background-color:F3F3F3" RunAt="Server"/> <!--**-->
</div>
</TD>
</TR>
<TR>
<TD Class="Spreadsheet" Align="Right" ColSpan="2">
<ASP:ImageButton ID="btnSave" OnClick="btnSave_OnClick" ImageUrl="/images/buttons/btnSave.gif" RunAt="Server"/>
</TD>
</TR>
</TABLE>
<!--- END YOUR CODE HERE!!!!! --->
</TD>
<!-- #INCLUDE VIRTUAL="/.../" -->
</TR>
<!-- #INCLUDE VIRTUAL="/.../" -->
</TABLE>
</TD>
<!-- #INCLUDE VIRTUAL="/.../" -->
</TR>
<!-- #INCLUDE VIRTUAL="/.../" -->
</TABLE>
</BASEFONT>
</FORM>
</BODY>
</HTML>
这是用C＃编写的Save按钮的（后端）代码：
public void btnSave_OnClick(object sender, System.Web.UI.ImageClickEventArgs E){
int counter = int.Parse(Request.Cookies["counter"].Value);
counter++;
Response.Cookies["counter"].Value = counter.ToString();
try{
SqlConnection Conn = GetConnection();
string SQL;
SqlCommand Cmd;
SqlDataReader Dtr;
if(hdFileID.Value=="")
{
Response.Write("Executing Save (adding new folder to DB");
SQL = "EXEC sp_File_Add @Name,@Description,@UserID";
Response.Write("Save successfully executed. Added to DB");
}
else
{
Response.Write("Executing Save (saving info of folder to DB");
SQL = "EXEC sp_File_Update @Name,@Description,@UserID,@FileID";
Response.Write("Save successfully executed. Saved to DB");
}
Cmd = new SqlCommand(SQL,Conn);
Cmd.Parameters.Add(new SqlParameter("@Name", SqlDbType.VarChar));
Cmd.Parameters["@Name"].Value = tbName.Text;
Cmd.Parameters.Add(new SqlParameter("@Description", SqlDbType.Text));
Cmd.Parameters["@Description"].Value = tbDescription.Text;
Cmd.Parameters.Add(new SqlParameter("@UserID", SqlDbType.Int));
Cmd.Parameters["@UserID"].Value = Convert.ToInt32(hdUserID_Global.Value);
if(hdFileID.Value!="")
{
Cmd.Parameters.Add(new SqlParameter("@FileID", SqlDbType.Int));
Cmd.Parameters["@FileID"].Value = Convert.ToInt32(hdFolderID.Value);
}
Cmd.ExecuteNonQuery();
if(hdFileID.Value=="")
{
SQL = "SELECT MAX(FileID) AS FileID FROM tbl_File WHERE CreatedByUserID=@UserID";
Cmd = new SqlCommand(SQL,Conn);
Cmd.Parameters.Add(new SqlParameter("@UserID", SqlDbType.Int));
Cmd.Parameters["@UserID"].Value = Convert.ToInt32(hdUserID_Global.Value);
Dtr = Cmd.ExecuteReader();
if(Dtr.Read())
{
hdFileID.Value = Dtr["FileID"].ToString();
}
Dtr.Close();
}
SQL = "DELETE FROM tbl_FileLicense ";
SQL += " WHERE FileID=@FileID ";
Cmd = new SqlCommand(SQL,Conn);
Cmd.Parameters.Add(new SqlParameter("@FileID", SqlDbType.Int));
Cmd.Parameters["@FileID"].Value = Convert.ToInt32(hdFileID.Value.ToString());
Cmd.ExecuteNonQuery();
if(ddLicense.Visible)
{
SQL = "EXEC sp_doc_Folder_Add @FileID,@LicenseID,@UserID";
Response.Write("Save successfully executed. Added to DB");
Cmd = new SqlCommand(SQL,Conn);
Cmd.Parameters.Add(new SqlParameter("@FolderID", SqlDbType.Int));
Cmd.Parameters["@FileID"].Value = Convert.ToInt32(hdFileID.Value.ToString());
Cmd.Parameters.Add(new SqlParameter("@LicenseID", SqlDbType.Int));
Cmd.Parameters["@LicenseID"].Value = Convert.ToInt32(ddLicense.SelectedItem.Value.ToString());
Cmd.Parameters.Add(new SqlParameter("@UserID", SqlDbType.Int));
Cmd.Parameters["@UserID"].Value = Convert.ToInt32(hdUserID_Global.Value);
Cmd.ExecuteNonQuery();
}
else
{
}
Conn.Close();
Response.Redirect("/Library/Default2.aspx?FileID=" + Request["RootFileID"].ToString());
Response.End();
}
catch (Exception e){
Response.Write("An error occurred while saving: " + e);
Response.End();
}
}
我一直在努力超过2天而且我不明白为什么按钮第一次没有点火，而是从第2次开始。任何帮助将不胜感激。谢谢。
答案 0 :(得分：0)
在执行UniqueMembers = uniqueList()方法之前，您应该打开连接，例如Conn.open()。
尝试使用此功能，如果它仍然不起作用，请在cmd.ExecuteNonQuery()的第一行，即webform.aspx添加此属性，看看它是否有效：<%@ Page Language="C#"。还可以通过设置断点来检查代码流。
答案 1 :(得分：0)
我通过在asp.net代码中的EnableViewState = False标记中添加<FORM runat="server">来实现它的工作