How to check datagridview column already exists with same Header Text Before adding a new Column in-CodePudding

I am trying to add columns dynamically to data grid view using VB.net. But the issue is I need to check that the column name already exists. before adding it if exists I want it to be cancelled automatically. I am using another form to select the Job Nos. which will add as Datagridview Header Text when it saved. () below is the code I am using to add a column to my datagridview. Hope you understand the question. I found some nearby answers in C# unfortunately I am not able to convert those correctly as my C# coding knowledge is little weak.

Thank You!

Dim FRMP = FrmEReview.ReviewGrid.Columns
Dim NOHRS As New DataGridViewTextBoxColumn
FRMP.Add(NOHRS) 
NOHRS.HeaderText = Me.Cmb_CName.Text & "-" & Me.Cmb_DName.Text 
NOHRS.Width = 160

CodePudding user response：

The obvious option - the one you should have been able to work out for yourself - is to simply loop through the columns and test the HeaderText of each one:

Dim headerText = $"{Cmb_CName.Text}-{Cmb_DName.Text}"
Dim headerTextFound = False

For Each column As DataGridViewColumn In FrmEReview.ReviewGrid.Columns
    If column.HeaderText = headerText Then
        headerTextFould = True
        Exit For
    End If
Next

If Not headerTextFound Then
    '...
End If

This is basically the code equivalent of what you'd do manually, which is why you should have been able to do it for yourself, at least mostly.

The not-so-obvious solution for a beginner is to use LINQ. LINQ is basically a means to flatten loops like this, so it leads to far more succinct code:

Dim headerText = $"{Cmb_CName.Text}-{Cmb_DName.Text}"

If FrmEReview.ReviewGrid.
              Columns.
              Cast(Of DataGridViewColumn)().
              All(Function(dgvc) dgvc.HeaderText <> headerText) Then
    '...
End If