Only writing selected datagridview rows to csv.

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The code below is used to write all data/enteries in the DataGridView to the csv. file, I would like to know how I can modify this, so that only rows selected via the dataGridViewCheckboxColumn will be written to the file, and not the whole thing.

What I have tried:

Dim StrExport As String = ""
For Each C As DataGridViewColumn In dataGVGeneral.Columns
    StrExport &= """" & C.HeaderText & ""","
Next
StrExport = StrExport.Substring(0, StrExport.Length - 1)
StrExport &= Environment.NewLine

For Each R As DataGridViewRow In dataGVGeneral.Rows
    For Each C As DataGridViewCell In R.Cells
        If Not C.Value Is Nothing Then
            StrExport &= """" & C.Value.ToString & ""","
        Else
            StrExport &= """" & "" & ""","
        End If
    Next
    StrExport = StrExport.Substring(0, StrExport.Length - 1)
    StrExport &= Environment.NewLine
Next

Dim tw As System.IO.TextWriter = New System.IO.StreamWriter("E:\SAT\Work.io\Work.io\bin\Debug\ListofTasks.csv", False)
tw.Write(StrExport)
tw.Close()

Posted 29-Jul-20 21:13pm

Shaheer Rizwan

Updated 29-Jul-20 21:37pm

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Comments

Garth J Lancaster 30-Jul-20 3:28am

c'mon - you've been through iterations of this before - if you have a checkbox column in the datagridview, then, while you're looping through the datagridview rows, if the cherckbox column .Selected = True then write that row, but build that row from the other columns not including the checkbox column

Shaheer Rizwan 30-Jul-20 3:32am

sorry, im a bit of a slow learner and noob. well thanks for this, will the
If clmSelected.Selected = True
Then
statement, before StrExport = StrExport.Substring(0, StrExport.Length -1)?

Richard MacCutchan 30-Jul-20 5:10am

Yes, just test the checkbox value of each entry as you process them. Why is that so complicated?

Shaheer Rizwan 30-Jul-20 6:02am

its just not working and im confused man

Richard MacCutchan 30-Jul-20 6:09am

The logic is fairly simple:

For Each Row in your datagridview:    
    If the checkbox column value is True
        Write the other column cells to the csv file
    End If
End For

So all you need to do is fill in the details ...

Richard MacCutchan 30-Jul-20 6:14am

Looking back at your other questions, six on this subject alone, I think you need to spend more time studying the C# language, and try some simpler exercises.

Shaheer Rizwan 30-Jul-20 6:15am

I just get stuck when it comes to actually implementing the stuff

Richard MacCutchan 30-Jul-20 7:13am

You need to be exact in your descriptions. What exactly is it that you do not understand? Reading the rows, getting the columns, testing the check box, writing the text ... ?

1 solution

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OriginalGriff · Answer 1 · 2020-07-29T21:37:00

Solution 1

Come on, this isn't complicated:
1) Identify the column containing the checkbox.
2) Inside your Rows loop, cast the current row / checkbox column cell to a check box, and test it's "Checked" property. If it's true, add it to the CSV. If it isn't, skip the row.

What part of that is difficult for you?

Posted 29-Jul-20 21:37pm

OriginalGriff

Comments

Shaheer Rizwan 30-Jul-20 3:40am

Im just newbie man. I get confused by what does what even though ive read it a million times.

Anyways, will this work

For Each R As DataGridViewRow In dataGVGeneral.Rows
If clmSelected.Selected = True Then
For Each C As DataGridViewCell In R.Cells
If Not C.Value Is Nothing Then
StrExport &= """" & C.Value.ToString & ""","
Else
StrExport &= """" & "" & ""","
End If
Next
StrExport = StrExport.Substring(0, StrExport.Length - 1)
StrExport &= Environment.NewLine
End If
Next

Garth J Lancaster 30-Jul-20 3:46am

will this work ? you ask - test it, find out, experiment - Information Technology IS a science - formulate a hypothesis (write some code), test it, modify it and try again

Shaheer Rizwan 30-Jul-20 4:01am

well i tried this and just no luck, I put the it before the For Loops, no luck.

Dim StrExport As String = ""
For Each C As DataGridViewColumn In dataGVGeneral.Columns
StrExport &= """" & C.HeaderText & ""","
Next
StrExport = StrExport.Substring(0, StrExport.Length - 1)
StrExport &= Environment.NewLine
If clmSelected.Selected = True Then
For Each R As DataGridViewRow In dataGVGeneral.Rows
For Each C As DataGridViewCell In R.Cells
If Not C.Value Is Nothing Then
StrExport &= """" & C.Value.ToString & ""","
Else
StrExport &= """" & "" & ""","
End If
Next
StrExport = StrExport.Substring(0, StrExport.Length - 1)
StrExport &= Environment.NewLine
Next
Dim tw As System.IO.TextWriter = New System.IO.StreamWriter("E:\SAT\Work.io\Work.io\bin\Debug\ListofTasks.csv", False)
tw.Write(StrExport)
tw.Close()
EndIf

OriginalGriff 30-Jul-20 4:55am

No. Why should it work? That's just "coding by guesswork" - and that never works well.

Go back to your original code, read what I said again, and think about what you need to do.

Shaheer Rizwan 30-Jul-20 6:07am

can you give me a clue or something man im really stuck :(

OriginalGriff 30-Jul-20 6:15am

How much more of a clue do you need?
Which column contains the checkbox?

Shaheer Rizwan 30-Jul-20 6:18am

I used this code, I get that if I make clmSelected.Selected = True, I have to run the loop. How do I get it to skip, If clmSelected.Selected = True then...

Private Sub btnToSession_Click(sender As Object, e As EventArgs) Handles btnToSession.Click
'Write to Session.csv to load into that Form easily
'Only selected value's via clmSelected
Dim StrExport As String = ""
For Each C As DataGridViewColumn In dataGVGeneral.Columns
StrExport &= """" & C.HeaderText & ""","
Next
StrExport = StrExport.Substring(0, StrExport.Length - 1)
StrExport &= Environment.NewLine

For Each R As DataGridViewRow In dataGVGeneral.Rows
'If clmSelected.Selected = True Then
For Each C As DataGridViewCell In R.Cells
If Not C.Value Is Nothing Then
StrExport &= """" & C.Value.ToString & ""","
Else
StrExport &= """" & "" & ""","
End If
Next
StrExport = StrExport.Substring(0, StrExport.Length - 1)
StrExport &= Environment.NewLine
'If clmSelected.Selected = False Then
'Skip to Next Row ?????
Next
Dim tw As System.IO.TextWriter = New System.IO.StreamWriter("E:\SAT\Work.io\Work.io\bin\Debug\Session.csv", False)
tw.Write(StrExport)
tw.Close()
End Sub
End Class

OriginalGriff 30-Jul-20 6:25am

Stop guessing; start thinking.
Which column contains the checkbox? Do you know?

Shaheer Rizwan 30-Jul-20 6:26am

yeah the 8th column, clmSelected

OriginalGriff 30-Jul-20 6:45am

Right. So for each row, you have a column that contains a checkbox.
So right at the top of your loop for all rows, get the value of the current row checkbox column.
That's not a "single value" - it need you to use the current DataGridViewRow to access a specific column by it's index - 7 for the 8th column or by a string name.

Can you do that? If so, put it as the first line of code inside your Rows loop, and show me the For Each loop line and the line of code immediately below it.

Shaheer Rizwan 30-Jul-20 7:11am

how would i call this underneath a Button Click event. I know you call it by e.ColumnIndex = when its an event relating to the DataGridView.

Shaheer Rizwan 30-Jul-20 7:12am

Also Im sorry for bothering you so much im just stressed and need this project done :(

OriginalGriff 30-Jul-20 7:18am

The DataGridViewRow object that changes each time round your Rows loop contains a Cells property: what do you suppose that holds? How do you think you access it?

Shaheer Rizwan 30-Jul-20 20:02pm

Well i did something and got it

Only writing selected datagridview rows to csv.

1 solution

Solution 1

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Only writing selected datagridview rows to csv.

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