Multi tool use

ASP.NET delete specific rows from gridview

I need help with following problem.
I try to delete specific rows from gridview.
Code bellow works well, but when page is loading its show all data in database.
How can I filter data? I mean when page is loading it shows nothing, but after type some text in text box, it shows me rows with that text and I can delete some of that rows with text from text box by check checkbox and button.

This is my code. Pls help me.

Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Load
If IsPostBack Then
GetData()
End If
BindGrid()
End Sub

Private Sub BindGrid()
Dim constr As String = ConfigurationManager _
.ConnectionStrings("conString").ConnectionString()
Dim query As String = "select * from TestCustomers"
Dim con As New SqlConnection(constr)
Dim sda As New SqlDataAdapter(query, con)
Dim dt As New DataTable()
sda.Fill(dt)
gvAll.DataSource = dt
gvAll.DataBind()
End Sub

Protected Sub OnPaging(ByVal sender As Object, ByVal e As GridViewPageEventArgs)
gvAll.PageIndex = e.NewPageIndex
gvAll.DataBind()
SetData()
End Sub

Private Sub GetData()
Dim arr As ArrayList
If ViewState("SelectedRecords") IsNot Nothing Then
arr = DirectCast(ViewState("SelectedRecords"), ArrayList)
Else
arr = New ArrayList()
End If
Dim chkAll As CheckBox = DirectCast(gvAll.HeaderRow _
.Cells(0).FindControl("chkAll"), CheckBox)
For i As Integer = 0 To gvAll.Rows.Count - 1
If chkAll.Checked Then
If Not arr.Contains(gvAll.DataKeys(i).Value) Then
arr.Add(gvAll.DataKeys(i).Value)
End If
Else
Dim chk As CheckBox = DirectCast(gvAll.Rows(i).Cells(0) _
.FindControl("chk"), CheckBox)
If chk.Checked Then
If Not arr.Contains(gvAll.DataKeys(i).Value) Then
arr.Add(gvAll.DataKeys(i).Value)
End If
Else
If arr.Contains(gvAll.DataKeys(i).Value) Then
arr.Remove(gvAll.DataKeys(i).Value)
End If
End If
End If
Next
ViewState("SelectedRecords") = arr
End Sub

Private Sub SetData()
Dim currentCount As Integer = 0
Dim chkAll As CheckBox = DirectCast(gvAll.HeaderRow _
.Cells(0).FindControl("chkAll"), CheckBox)
chkAll.Checked = True
Dim arr As ArrayList = DirectCast(ViewState("SelectedRecords") _
, ArrayList)
For i As Integer = 0 To gvAll.Rows.Count - 1
Dim chk As CheckBox = DirectCast(gvAll.Rows(i).Cells(0) _
.FindControl("chk"), CheckBox)
If chk IsNot Nothing Then
chk.Checked = arr.Contains(gvAll.DataKeys(i).Value)
If Not chk.Checked Then
chkAll.Checked = False
Else
currentCount += 1
End If
End If
Next
hfCount.Value = (arr.Count - currentCount).ToString()
End Sub

Protected Sub btnDelete_Click(ByVal sender As Object, ByVal e As EventArgs)
Dim count As Integer = 0
SetData()
gvAll.AllowPaging = False
gvAll.DataBind()
Dim arr As ArrayList = DirectCast(ViewState("SelectedRecords") _
, ArrayList)
count = arr.Count
For i As Integer = 0 To gvAll.Rows.Count - 1
If arr.Contains(gvAll.DataKeys(i).Value) Then
DeleteRecord(gvAll.DataKeys(i).Value.ToString())
arr.Remove(gvAll.DataKeys(i).Value)
End If
Next
ViewState("SelectedRecords") = arr
hfCount.Value = "0"
gvAll.AllowPaging = True
BindGrid()
ShowMessage(count)
End Sub

Private Sub DeleteRecord(ByVal CustomerID As String)
Dim constr As String = ConfigurationManager _
.ConnectionStrings("conString").ConnectionString
Dim query As String = "delete from TestCustomers where" & _
" CustomerID=@CustomerID"
Dim con As New SqlConnection(constr)
Dim cmd As New SqlCommand(query, con)
cmd.Parameters.AddWithValue("@CustomerID", CustomerID)
con.Open()
cmd.ExecuteNonQuery()
con.Close()
End Sub

Private Sub ShowMessage(ByVal count As Integer)
Dim sb As New StringBuilder()
sb.Append("<script type = 'text/javascript'>")
sb.Append("alert('")
sb.Append(count.ToString())
sb.Append(" records deleted.');")
sb.Append("</script>")
ClientScript.RegisterStartupScript(Me.GetType(), _
"script", sb.ToString())
End Sub

<asp:GridView ID="gvAll" runat="server"
AutoGenerateColumns = "false" Font-Names = "Arial"
Font-Size = "11pt" AlternatingRowStyle-BackColor = "#C2D69B"
HeaderStyle-BackColor = "green" AllowPaging ="true"
OnPageIndexChanging = "OnPaging" DataKeyNames = "CustomerID"
PageSize = "10" >
<Columns>
<asp:TemplateField>
<HeaderTemplate>
<asp:CheckBox ID="chkAll" runat="server" onclick = "checkAll(this);" />
</HeaderTemplate>
<ItemTemplate>
<asp:CheckBox ID="chk" runat="server" onclick = "Check_Click(this)"/>
</ItemTemplate>
</asp:TemplateField>
<asp:BoundField ItemStyle-Width = "150px" DataField = "ContactName" HeaderText = "Contact Name"/>
<asp:BoundField ItemStyle-Width = "150px" DataField = "Country" HeaderText = "Country"/>
<asp:BoundField ItemStyle-Width = "150px" DataField = "City" HeaderText = "City"/>
</Columns>
<AlternatingRowStyle BackColor="#C2D69B" />
</asp:GridView>
<asp:HiddenField ID="hfCount" runat="server" Value = "0" />
<asp:Button ID="btnDelete" runat="server" Text="Delete Checked Records" OnClientClick = "return ConfirmDelete();" OnClick="btnDelete_Click" />


2 Answers
2

Even though your question is not clear , i will answer what i have understood.

you want to show all data on page load and on postback you want to show selected rows , right ?

if yes

try this code
If IsPostBack Then
GetData()
End If

else
BindGrid()

if this has not answered your question , please tell me what exactly you want to do.

This will delete all rows that had been selected.

For Each row As DataGridViewRow In yourDGV.SelectedRows
yourDGV.Rows.Remove(row)
Next


Private Sub btndelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btndelete.Click
If DataGridView1.SelectedRows.Count > 0 Then
DataGridView1.Rows.RemoveAt(DataGridView1.CurrentRow.Index)
Else
MessageBox.Show("You must select a row")
End If
End Sub


Use this it may help full to you

Protected Sub btnDelete_Click(ByVal sender As Object, ByVal e As EventArgs)
For Each gvrow As GridViewRow In gvDetails.Rows
'Finiding checkbox control in gridview for particular row
Dim chkdelete As CheckBox = DirectCast(gvrow.FindControl("chkSelect"), CheckBox)
'Condition to check checkbox selected or not
If chkdelete.Checked Then
'Getting UserId of particular row using datakey value
Dim usrid As Integer = Convert.ToInt32(gvDetails.DataKeys(gvrow.RowIndex).Value)
Using con As New SqlConnection("YOUR SQL DATABASE CONNECTION")
con.Open()
Dim cmd As New SqlCommand("delete from UserDetails where UserId=" & usrid, con)
cmd.ExecuteNonQuery()
con.Close()
End Using
End If
Next
BindUserDetails()
End Sub


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