C# 无法清除GridView的最后一个数据源

首先，我选择页面加载上的所有记录，如下所示：

OleDbCommand objCmd = new OleDbCommand("SELECT * FROM MyTable", mycon);
objCmd.CommandType = CommandType.Text;
DataTable dtTemp = new DataTable();
OleDbDataReader rd = objCommand.ExecuteReader();
if (rd.HasRows)
{
    dtTemp.Load(rd);
    gvTemp.DataSource = dtTemp;
    gvTemp.DataBind();
}

<asp:TemplateField HeaderText="Action" ItemStyle-Width="80px">
    <ItemTemplate>
        <asp:LinkButton ID="lbtnStart" runat="server" CommandArgument='<%# Eval("MemID") %>' CommandName="Start">Start</asp:LinkButton>
    </ItemTemplate>
</asp:TemplateField>

OleDbCommand objCmd = new OleDbCommand("SELECT * FROM MyTable WHERE MemID = ?", mycon);
objCmd.Parameters.Add(myParam); 
objCmd.CommandType = CommandType.Text;
DataTable dtTemp = new DataTable();
OleDbDataReader rd = objCommand.ExecuteReader();
if (rd.HasRows)
{
    dtTemp.Load(rd);
    gvTemp.DataSource = dtTemp;
    gvTemp.DataBind();
}

gvTemp.DataSource = null;
gvTemp.DataBind();
gvTemp.DataSource = dtTemp;
gvTemp.DataBind();

if(!IsPostBack)
   //Your code or method for selecting all records.

在GridView（

gvTemp

）中，我在

CommandArgument

中传递

MemID

，如下所示：

OleDbCommand objCmd = new OleDbCommand("SELECT * FROM MyTable", mycon);
objCmd.CommandType = CommandType.Text;
DataTable dtTemp = new DataTable();
OleDbDataReader rd = objCommand.ExecuteReader();
if (rd.HasRows)
{
    dtTemp.Load(rd);
    gvTemp.DataSource = dtTemp;
    gvTemp.DataBind();
}

<asp:TemplateField HeaderText="Action" ItemStyle-Width="80px">
    <ItemTemplate>
        <asp:LinkButton ID="lbtnStart" runat="server" CommandArgument='<%# Eval("MemID") %>' CommandName="Start">Start</asp:LinkButton>
    </ItemTemplate>
</asp:TemplateField>

OleDbCommand objCmd = new OleDbCommand("SELECT * FROM MyTable WHERE MemID = ?", mycon);
objCmd.Parameters.Add(myParam); 
objCmd.CommandType = CommandType.Text;
DataTable dtTemp = new DataTable();
OleDbDataReader rd = objCommand.ExecuteReader();
if (rd.HasRows)
{
    dtTemp.Load(rd);
    gvTemp.DataSource = dtTemp;
    gvTemp.DataBind();
}

gvTemp.DataSource = null;
gvTemp.DataBind();
gvTemp.DataSource = dtTemp;
gvTemp.DataBind();

if(!IsPostBack)
   //Your code or method for selecting all records.

这工作做得很好。但问题就在这里。
当用户搜索特定记录时，我重新加载

gvTemp

，如下所示：

OleDbCommand objCmd = new OleDbCommand("SELECT * FROM MyTable", mycon);
objCmd.CommandType = CommandType.Text;
DataTable dtTemp = new DataTable();
OleDbDataReader rd = objCommand.ExecuteReader();
if (rd.HasRows)
{
    dtTemp.Load(rd);
    gvTemp.DataSource = dtTemp;
    gvTemp.DataBind();
}

<asp:TemplateField HeaderText="Action" ItemStyle-Width="80px">
    <ItemTemplate>
        <asp:LinkButton ID="lbtnStart" runat="server" CommandArgument='<%# Eval("MemID") %>' CommandName="Start">Start</asp:LinkButton>
    </ItemTemplate>
</asp:TemplateField>

OleDbCommand objCmd = new OleDbCommand("SELECT * FROM MyTable WHERE MemID = ?", mycon);
objCmd.Parameters.Add(myParam); 
objCmd.CommandType = CommandType.Text;
DataTable dtTemp = new DataTable();
OleDbDataReader rd = objCommand.ExecuteReader();
if (rd.HasRows)
{
    dtTemp.Load(rd);
    gvTemp.DataSource = dtTemp;
    gvTemp.DataBind();
}

gvTemp.DataSource = null;
gvTemp.DataBind();
gvTemp.DataSource = dtTemp;
gvTemp.DataBind();

if(!IsPostBack)
   //Your code or method for selecting all records.

执行此查询时，我只得到一条记录。当我点击

Start

，就会触发

gvTemp\u RowCommand

。但是我得到了旧数据源的

e.CommandArgument

。（即

SELECT*FROM MyTable

的前1个

MemID

）。因此，在绑定实际数据源之前，我清除GridView，如下所示：

OleDbCommand objCmd = new OleDbCommand("SELECT * FROM MyTable", mycon);
objCmd.CommandType = CommandType.Text;
DataTable dtTemp = new DataTable();
OleDbDataReader rd = objCommand.ExecuteReader();
if (rd.HasRows)
{
    dtTemp.Load(rd);
    gvTemp.DataSource = dtTemp;
    gvTemp.DataBind();
}

<asp:TemplateField HeaderText="Action" ItemStyle-Width="80px">
    <ItemTemplate>
        <asp:LinkButton ID="lbtnStart" runat="server" CommandArgument='<%# Eval("MemID") %>' CommandName="Start">Start</asp:LinkButton>
    </ItemTemplate>
</asp:TemplateField>

OleDbCommand objCmd = new OleDbCommand("SELECT * FROM MyTable WHERE MemID = ?", mycon);
objCmd.Parameters.Add(myParam); 
objCmd.CommandType = CommandType.Text;
DataTable dtTemp = new DataTable();
OleDbDataReader rd = objCommand.ExecuteReader();
if (rd.HasRows)
{
    dtTemp.Load(rd);
    gvTemp.DataSource = dtTemp;
    gvTemp.DataBind();
}

gvTemp.DataSource = null;
gvTemp.DataBind();
gvTemp.DataSource = dtTemp;
gvTemp.DataBind();

if(!IsPostBack)
   //Your code or method for selecting all records.

---

但我仍然得到了旧数据源的

e.CommandArgument

。那么我错过了什么？或者是否有其他方法可以实现同样的效果？

在每次单击按钮时，都会发生回发和页面加载事件，因此在您的情况下，这可能是加载上一个数据源的原因。因此，您必须检查iPostBack条件

试着这样做：

OleDbCommand objCmd = new OleDbCommand("SELECT * FROM MyTable", mycon);
objCmd.CommandType = CommandType.Text;
DataTable dtTemp = new DataTable();
OleDbDataReader rd = objCommand.ExecuteReader();
if (rd.HasRows)
{
    dtTemp.Load(rd);
    gvTemp.DataSource = dtTemp;
    gvTemp.DataBind();
}

<asp:TemplateField HeaderText="Action" ItemStyle-Width="80px">
    <ItemTemplate>
        <asp:LinkButton ID="lbtnStart" runat="server" CommandArgument='<%# Eval("MemID") %>' CommandName="Start">Start</asp:LinkButton>
    </ItemTemplate>
</asp:TemplateField>

OleDbCommand objCmd = new OleDbCommand("SELECT * FROM MyTable WHERE MemID = ?", mycon);
objCmd.Parameters.Add(myParam); 
objCmd.CommandType = CommandType.Text;
DataTable dtTemp = new DataTable();
OleDbDataReader rd = objCommand.ExecuteReader();
if (rd.HasRows)
{
    dtTemp.Load(rd);
    gvTemp.DataSource = dtTemp;
    gvTemp.DataBind();
}

gvTemp.DataSource = null;
gvTemp.DataBind();
gvTemp.DataSource = dtTemp;
gvTemp.DataBind();

if(!IsPostBack)
   //Your code or method for selecting all records.

---

为什么不简单地删除

响应。重定向（自身）

并使用方法和属性

private string MemID{
    get { return (String)ViewState["MemID"]; }
    set { ViewState["MemID"] = value; }
}

private void BindGrid()
{
    // copy your sql,datasource and databind stuff here, use the MemID property for the parameter
}

protected void gvTemp_RowCommand(object sender, GridViewCommandEventArgs e)
{
    if (e.CommandName == "Start")
    {
        MemID = e.CommandArgument.ToString());
        BindGrid();
    }
}

---

您传入的

objCmd.Parameters.Add（myParam）的
myParam
的值是多少？尝试刷新（）或。重置绑定可能会影响它solve@prashanth我从方法参数中获取它的值。@GyanChandraSrivastava不是
Refresh（）
和
ResetBinding（）
是
DataGridView
的方法。我这里有
GridView
。实际上，
AddMem.aspx
是另一个页面。我要通过的位置
MemID