DataGridView获取预先更改的单元格值

Question

I am trying to get the value of a cell right before it changes. So when I do a .Text change, I want to grab the pre-change value before doing the text change. Is there an event that will fire allowing me to get this data?

I have tried using BeginCellEdit, CellValidating, ect... but none of these are firing, they don't even hit my break points on the method call when a value is updated.

I would rather not have to manually drop a lot of get .Texts during changes, and just want one event to get pre-changed values. Are there any other methods or ways to get a pre-changed cell value?

Answer 1

How about creating a method that eliminates the need for duplicate code?

Instead of calling this:

frameGridView.Rows[frameNumber].Cells[1].Value = subArray[0];

Create a method that does what you need with the old value, before it actually updates the cell:

private void UpdateGrid(int rowIndex, int columnIndex, string newValue)
{
    var cell = frameGridView.Rows[frameNumber].Cells[1];

    var oldValue = Convert.ToString(cell.Value);
    // display oldValue in the section that shows recent changes

    cell.Value = newValue;  // update the cell
}

Then call it likewise:

UpdateGrid(frameNumber, 1, subArray[0]);

Answer 2

I hope that will help you:

private string oldValue;
private bool isValid;

void myDataGridView_CellValidating(object sender, DataGridViewCellValidatingEventArgs e)
{
 this.isValid= true;
 this.oldValue= Convert.ToString(this[e.ColumnIndex, e.RowIndex].Value);

 if (!isValid(this.myDataGridView(e))
 isValid= false;
}

void myDataGridView_CellValidated(object sender, DataGridViewCellValidatingEventArgs e)
{
 if (!isValid)
 this[e.ColumnIndex, e.RowIndex].Value = this.oldValue;
}