如何在Delphi XE5上通过代码触发网格双右边框单击事件？

Question

I m using Dev Express DBGrid component, I want to scale my column to fit my rows text so I used :

cxView.ApplyBestFit();

That works but somehow too slow, so I did some search and I found this post on Dev Express Website but this don't help me much. So i started observing the grid interactivity what lead me to discover that if I double click all right borders of the grid one after other the grid will scale perfectly and quickly as you see in the two pictures below :

then i continue to the last border to get this result :

I m trying desperate to fire this double clicks by code but I lack experience on Delphi and Dev Express. So how to fire this event successively in all columns one by one.

Thank you

Answer 1

The code below will do the same as double-clicking the rhs of each header cell.

Code:

procedure TForm1.ApplyBestFits;
var
  i : Integer;
begin
  try
    cxGrid1DBTableView1.BeginUpdate;
    for i := 0 to cxGrid1DBTableView1.ColumnCount - 1 do begin
      cxGrid1DBTableView1.Columns[i].ApplyBestFit;
    end;
  finally
    cxGrid1DBTableView1.EndUpdate;
  end;
end;

However, I'm not sure that as it stands it is a complete solution to your problem. In my test case, with 100 columns and 2000 data rows, it takes a second or two to execute, which I imagine is much slower than you were hoping. So it may need some optimization.

One obvious optimization would be to only call cxGrid1DBTableView1.Columns[i].ApplyBestFit for columns that are within the client rect of the DBTableView. Another might be to restrict the number of rows in the dataset connected to the tableview to a lower number. For instance, the following only calls ApplyBestFit to columns whose Left coordinate is within the width of the cxGrid.

procedure TForm1.ApplyBestFits;
var
  i : Integer;
  ALeft : Integer;
  ACol : TcxGridColumn;
begin
  try
    ALeft := 0;
    cxGrid1DBTableView1.BeginUpdate;
    //  Process only the visible columns whose Left properties
    //  are within the width of the grid
    for i := 0 to cxGrid1DBTableView1.VisibleColumnCount - 1 do begin
      ACol := cxGrid1DBTableView1.VisibleColumns[i];
      ACol.ApplyBestFit;
      Inc(ALeft, ACol.Width);
      if ALeft > cxGrid1.Width then
        Break;
    end;
  finally
    cxGrid1DBTableView1.EndUpdate;
  end;
end;