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我们有一对夫妇的GridView控件，grvSource和grvSpouse的，每个动态地添加其他行，当你点击每下面的屏幕截图添加按钮：为什么点击添加按钮后输入的数据会消失？
在顶部图像标记，用户输入数据输入三个单元格中的每一个，然后单击按钮以创建一个额外的行。
的问题是，一旦添加按键，就可将数据录入第一行消失在标图片，如图所示。
任何想法为什么会发生这种情况？
<asp:GridView ID="grvSource" AutoGenerateColumns="false" gridlines="None" ShowFooter="true" runat="server" OnRowDataBound="grvSource_RowDataBound"
OnRowDeleting="grvSource_RowDeleting">
<Columns>
<asp:TemplateField HeaderText="Name">
<headerstyle horizontalalign="Left" />
<ItemTemplate>
<asp:TextBox ID="txtsourcename" placeholder="Name..." runat="server" Style="width: 250px;
height: 20px" class="form-control"></asp:TextBox>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Address">
<headerstyle horizontalalign="Center" />
<ItemTemplate>
<asp:TextBox ID="txtsourceaddress" placeholder="Address..." runat="server" Style="width: 250px;
height: 20px" class="form-control"></asp:TextBox>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Income">
<headerstyle horizontalalign="Center" />
<ItemTemplate>
<asp:TextBox ID="txtsourceincome" placeholder="Income..." runat="server" Style="width: 250px;
height: 20px" class="form-control"></asp:TextBox>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText=" ">
<ItemTemplate>
<asp:Button ID="ButtonAdd1" runat="server" Text="Add" OnClick="ButtonAdd1_Click" CssClass="grvAddButton" OnClientClick="return ValidateEmptyValue();" />
</ItemTemplate>
</asp:TemplateField>
<asp:CommandField ShowDeleteButton="True">
<ControlStyle CssClass="grvDelButton" />
</asp:CommandField>
</Columns>
</asp:GridView>
<br />
<asp:GridView ID="grvSpouse" AutoGenerateColumns="false" gridlines="None" ShowFooter="true" runat="server" OnRowDataBound="grvSpouse_RowDataBound"
OnRowDeleting="grvSpouse_RowDeleting">
<Columns>
<asp:TemplateField HeaderText="Name">
<headerstyle horizontalalign="Left" />
<ItemTemplate>
<asp:TextBox ID="txtspousename" placeholder="Name..." runat="server" Style="width: 250px;
height: 20px" class="form-control"></asp:TextBox>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Address">
<headerstyle horizontalalign="Center" />
<ItemTemplate>
<asp:TextBox ID="txtspouseaddress" placeholder="Address..." runat="server" Style="width: 250px;
height: 20px" class="form-control"></asp:TextBox>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Income">
<headerstyle horizontalalign="Center" />
<ItemTemplate>
<asp:TextBox ID="txtspouseincome" placeholder="Income..." runat="server" Style="width: 250px;
height: 20px" class="form-control"></asp:TextBox>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText=" ">
<ItemTemplate>
<asp:Button ID="ButtonAdd2" runat="server" Text="Add" OnClick="ButtonAdd2_Click"
CssClass="grvAddButton" OnClientClick="return ValidateSPEmptyValue();" />
</ItemTemplate>
</asp:TemplateField>
<asp:CommandField ShowDeleteButton="True">
<ControlStyle CssClass="grvDelButton" />
</asp:CommandField>
</Columns>
</asp:GridView>
'//Codefile
Protected Sub Page_Load(sender As Object, e As System.EventArgs) Handles Me.Load
If Not IsPostBack Then
Me.SetInitialRow()
End If
End Sub
Private Sub SetInitialRow()
Dim dt As New DataTable()
Dim dr As DataRow = Nothing
dt.Columns.Add(New DataColumn("RowNumber", GetType(String)))
dt.Columns.Add(New DataColumn("Column1", GetType(String)))
dt.Columns.Add(New DataColumn("Column2", GetType(String)))
dt.Columns.Add(New DataColumn("Column3", GetType(String)))
dr = dt.NewRow()
dr("RowNumber") = 1
dr("Column1") = String.Empty
dr("Column2") = String.Empty
dr("Column3") = String.Empty
dt.Rows.Add(dr)
ViewState("CurrentTable" & 0) = dt
ViewState("CurrentTable" & 1) = dt
BindGridview()
End Sub
Private Sub BindGridview()
Dim dt As DataTable = DirectCast(ViewState("CurrentTable" & 0), DataTable)
grvSource.DataSource = dt
grvSource.DataBind()
Dim dt1 As DataTable = DirectCast(ViewState("CurrentTable" & 1), DataTable)
grvSpouse.DataSource = dt1
End Sub
Protected Sub GrvSource_RowDataBound(sender As Object, e As GridViewRowEventArgs)
If e.Row.RowType = DataControlRowType.Header Then
If e.Row.RowIndex = -1 Then
DirectCast(DirectCast(e.Row.Cells(4), DataControlFieldCell).ContainingField, CommandField).ShowDeleteButton = False
End If
Else
If Convert.ToInt32(ViewState("rowIndex" & 0)) = e.Row.RowIndex Then
DirectCast(DirectCast(e.Row.Cells(4), DataControlFieldCell).ContainingField, CommandField).ShowDeleteButton = True
End If
End If
End Sub
Protected Sub GrvSpouse_RowDataBound(sender As Object, e As GridViewRowEventArgs)
If e.Row.RowType = DataControlRowType.Header Then
If e.Row.RowIndex = -1 Then
DirectCast(DirectCast(e.Row.Cells(4), DataControlFieldCell).ContainingField, CommandField).ShowDeleteButton = False
End If
Else
If Convert.ToInt32(ViewState("rowIndex" & 1)) = e.Row.RowIndex Then
DirectCast(DirectCast(e.Row.Cells(4), DataControlFieldCell).ContainingField, CommandField).ShowDeleteButton = True
End If
End If
End Sub
Private Sub AddNewRowToGrid(viewId As Integer, gv As GridView)
Dim rowIndex As Integer = 0
If ViewState("CurrentTable" & viewId) IsNot Nothing Then
Dim dtCurrentTable As DataTable = DirectCast(ViewState("CurrentTable" & viewId), DataTable)
Dim drCurrentRow As DataRow = Nothing
If dtCurrentTable.Rows.Count > 0 Then
For i As Integer = 1 To dtCurrentTable.Rows.Count
Dim box1 As New TextBox()
Dim box2 As New TextBox()
Dim box3 As New TextBox()
If viewId = 0 Then
box1 = DirectCast(gv.Rows(rowIndex).Cells(1).FindControl("txtsourcename"), TextBox)
box2 = DirectCast(gv.Rows(rowIndex).Cells(2).FindControl("txtsourceaddress"), TextBox)
box3 = DirectCast(gv.Rows(rowIndex).Cells(3).FindControl("txtsourceincome"), TextBox)
End If
If viewId = 1 Then
box1 = DirectCast(gv.Rows(rowIndex).Cells(1).FindControl("txtspousename"), TextBox)
box2 = DirectCast(gv.Rows(rowIndex).Cells(2).FindControl("txtspouseaddress"), TextBox)
box3 = DirectCast(gv.Rows(rowIndex).Cells(3).FindControl("txtspouseincome"), TextBox)
End If
drCurrentRow = dtCurrentTable.NewRow()
drCurrentRow("RowNumber") = i + 1
dtCurrentTable.Rows(i - 1)("Column1") = box1.Text
dtCurrentTable.Rows(i - 1)("Column2") = box2.Text
dtCurrentTable.Rows(i - 1)("Column3") = box3.Text
rowIndex += 1
Next
dtCurrentTable.Rows.Add(drCurrentRow)
ViewState("CurrentTable" & viewId) = dtCurrentTable
gv.DataSource = dtCurrentTable
gv.DataBind()
End If
Else
Response.Write("ViewState is null")
End If
SetPreviousData(viewId, gv)
End Sub
Private Sub SetPreviousData(viewId As Integer, gv As GridView)
Dim rowIndex As Integer = 0
If ViewState("CurrentTable" & viewId) IsNot Nothing Then
Dim dt As DataTable = DirectCast(ViewState("CurrentTable" & viewId), DataTable)
If dt.Rows.Count > 0 Then
For i As Integer = 0 To dt.Rows.Count - 1
Dim box1 As New TextBox()
Dim box2 As New TextBox()
Dim box3 As New TextBox()
If viewId = 0 Then
box1 = DirectCast(gv.Rows(rowIndex).Cells(1).FindControl("txtsourcename"), TextBox)
box2 = DirectCast(gv.Rows(rowIndex).Cells(2).FindControl("txtsourceaddress"), TextBox)
box3 = DirectCast(gv.Rows(rowIndex).Cells(3).FindControl("txtsourceincome"), TextBox)
End If
If viewId = 1 Then
box1 = DirectCast(gv.Rows(rowIndex).Cells(1).FindControl("txtspousename"), TextBox)
box2 = DirectCast(gv.Rows(rowIndex).Cells(2).FindControl("txtspouseaddress"), TextBox)
box3 = DirectCast(gv.Rows(rowIndex).Cells(3).FindControl("txtspouseincome"), TextBox)
End If
box1.Text = dt.Rows(i)("Column1").ToString()
box2.Text = dt.Rows(i)("Column2").ToString()
box3.Text = dt.Rows(i)("Column3").ToString()
rowIndex += 1
Next
End If
End If
End Sub
Protected Sub ButtonAdd1_Click(sender As Object, e As EventArgs)
Dim row As GridViewRow = TryCast(TryCast(sender, Button).NamingContainer, GridViewRow)
If grvSource.Rows.Count - 1 = row.RowIndex Then
ViewState("rowIndex" & 0) = row.RowIndex
End If
AddNewRowToGrid(0, grvSource)
Me.BindGridview()
End Sub
Protected Sub ButtonAdd2_Click(sender As Object, e As EventArgs)
Dim row As GridViewRow = TryCast(TryCast(sender, Button).NamingContainer, GridViewRow)
If grvSpouse.Rows.Count - 1 = row.RowIndex Then
ViewState("rowIndex" & 1) = row.RowIndex
End If
AddNewRowToGrid(1, grvSpouse)
Me.BindGridview()
End Sub
'///Errors:
There is no row at position -1.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.IndexOutOfRangeException: There is no row at position -1.
Source Error:
Line 231: drCurrentRow = dtCurrentTable.NewRow()
Line 232: drCurrentRow("RowNumber") = i + 1
Line 233: dtCurrentTable.Rows(i - 1)("Column1") = box1.Text
Line 234: dtCurrentTable.Rows(i - 1)("Column2") = box2.Text
Line 235: dtCurrentTable.Rows(i - 1)("Column3") = box3.Text
Source File: C:\inetpub\wwwroot\folder\closures.aspx.vb Line: 233
Line 233 starts from here:
dtCurrentTable.Rows(i - 1)("Column1") = box1.Text
on the AddNewRowToGrib sub.
This has been the consistent error.
This error occurs when I enter data into the first row and click the Add button to add another row
I remove the "0" in CurrentTable, when I try to run the code, I get the following error:
Object reference not set to an instance of an object.
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.
Source Error:
Line 87: Dim dtCurrentTable As DataTable = DirectCast(ViewState("CurrentTable"), DataTable)
Line 88: If e.Row.RowType = DataControlRowType.DataRow Then
Line 89: If dtCurrentTable.Rows.Count > 0 Then
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注释不适用于扩展讨论;这个对话已经[转移到聊天]（http://chat.stackoverflow.com/rooms/141903/discussion-on-question-by-kenny-why-is-entered-data-disappearing-after-i-click- T）。 –