DataGridView Loop + Compare

obrienkev · December 24th, 2007, 05:50 AM

Hi,

I have 2 columns in my DataGridView.

The first column - "IDColumn" is populated from a datasource unrelated to the other column.

I want to use each "IDColumn" value to compare against values returned from another Dataset query (myDataSet).

Then if there's a match I want the image to display in the "MessageColumn" only.

How do I do this? Thanks.

My code below displays the image in both columns.

Code:

private void myDataGridView_CellFormatting(object sender, DataGridViewCellFormattingEventArgs e)
{
for (int iRow = 0; iRow < myDataGridView.Rows.Count -1; iRow++)
{

string SelectedID = myDataGridView.Rows[iRow].Cells["IDColumn"].Value.ToString();

foreach (DataRow myRow in this.myDataSet.Tables["Approved"].Rows)
{
if (myRow["Portfolio"].ToString() == SelectedID)
{
if (myDataGridView.Columns[e.ColumnIndex].Name == "MessageColumn")
{
e.Value = Properties.Resources.LightGreen;
}
}
}
}
}

plmyfinger · December 30th, 2007, 07:53 PM

im not sure if you want to simply change the color of the cell in a row that has a matching profolio id of the approved portfolio's, but it should probably done a bit differently. Currently your code requires # of items in the DataGridView * # of items in the DataSet. Whats worse is that you are trapping the CellFormatting handler which is fired each time a row needs to be repainted.

Quick Solution:
Replace

Code:

e.Value = Properties.Resources.LightGreen;

with

Code:

try{
 myDataGridView.Rows[iRow].Cells["MessageColumn"].Style.BackColor = Color.LightGreen;
} catch (Exception e){ Console.WriteLine(e.Message); }

Long Solution:

Rewrite this to trap the DataSourceChanged or CellValueChanged depending on other factors of your app. When filling your dataset use adapter.FillSchema(ds) first to gather any primary keys and metadata. Assuming you have primary keys defined, you can query the dataset for specific items using (Assuming your DataSet is named ds)

Code:

ds.Tables[0].Rows.Find({PrimaryKey})

or

Code:

ds.Tables[0].Select ("Portfolio=" + SelectedID); //Returns a DataRow[] array but in your case should only have 1 row

then you can simply say

Code:

if(ds.Tables[0].Select ("Portfolio=" + SelectedID) != null){
//then a match was found; mark this row
  myDataGridView.Rows[iRow].Cells["MessageColumn"].Style.BackColor = Color.LightGreen; 
}