VB.NET-A way to insert rows into datagrid or datatable - vb.net

Question

Hi once again am stuck in middle where i need some pointer.... I need a way fill the datagrid in a for loop...
Dim rs As SqlCommand
Dim dt As New DataTable
For Each line As String In RichTextBox1.Lines
query = "myquery '" & RichTextBox1.Lines(i).ToString & "'"
rs = New SqlCommand(query, Module1.dtsrv_conn)
dt.load(rs.Executereader)
If i < 1 Then
DataGridView1.DataSource = dt
Else
datagridview1.rows.Add(rs.ExecuteReader)
End If
i = i + 1
Next
many lines of text will be entered in RichTextBox and each line need to be compared with values in database and the resulted table need to be shown in datagrid... I tried adding the newly queried row to datagrid directly but it throws exception so i tried to add new row to datatable and load the datagrid later but i cant find a way....

Answer 1

If I understand your question which isn't very clear, the user is entering values that you want to query against rows in your database and if they exist, display some corresponding data or message.
It sounds like what you want to do is bind your datagrid to a datasource, in my example an in-memory datatable, then intercept the data binding via DataGridView1.CellFormatting to compare/modify your data accordingly.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Dim sqlConnection As SqlConnection
Dim sqlConnectionString As String = "YourConnectionString"
Dim sqlDataAdapter As SqlDataAdapter
Dim dataTable As New DataTable
Dim sqlCommand As SqlCommand
Dim sqlString As String
Try
sqlString = "SELECT * FROM YourTable" 'if user input values are filters, loop through and append them in WHERE clause
sqlConnection = New SqlConnection(sqlConnectionString)
sqlCommand = New SqlCommand(sqlString, sqlConnection)
sqlConnection.Open()
sqlDataAdapter = New SqlDataAdapter(sqlCommand)
sqlDataAdapter.Fill(dataTable)
sqlConnection.Close()
DataGridView1.DataSource = dataTable
Catch ex As Exception
'Handle error
End Try
End Sub
Private Sub DataGridView1_CellFormatting(sender As Object, e As DataGridViewCellFormattingEventArgs) Handles DataGridView1.CellFormatting
If Me.DataGridView1.Columns(e.ColumnIndex).Name = "YourColumnNameToCompare" Then
If e.Value IsNot Nothing Then
'do your comparison to user input text here and if necassary change the value like so..
For Each line In RichTextBox1.Lines
If line = e.Value Then
e.Value = "Value modified"
Exit For
End If
Next
e.FormattingApplied = True
End If
End If
End Sub