Styjun

I am searching in a datagrid through a textbox and my code highlights the searched text in datagrid cells and filter the rows according to the search.This works fine for small number of rows but as the row increase it gets very slow.If someone can suggest anything to make it more efficient, I would be thankful :)

To highlight search text in datagrid cells

public void HighlightSearch()
 
 if (string.IsNullOrEmpty(SearchText))
 
 if ((dataGrid.ItemsSource as DataView).RowFilter == "")
 return;
 
 string searchtext = SearchText;
 Regex SearchRegex = new Regex(searchtext, RegexOptions.IgnoreCase);
 if (dataGrid.ItemsSource != null)
 
 for (int i = 0; i < dataGrid.Columns.Count; i++)
 
 var checkbox = SearchColumns[i];
 if (checkbox.IsChecked == true)
 
 for (int j = 0; j < dataGrid.Items.Count; j++)
 
 DataGridCell cell = GetCell(j, i);
 string[] substrings =null;
 if (cell.Content is TextBlock itx)
 
 Regex regex = new Regex("(" + SearchText + ")", RegexOptions.IgnoreCase);
 TextBlock tb = itx as TextBlock;
 if (SearchText.Length == 0)
 
 string str = tb.Text;
 tb.Inlines.Clear();
 tb.Inlines.Add(str);
 
 else
 
 substrings = regex.Split(tb.Text);
 tb.Inlines.Clear();
 foreach (var item in substrings)
 
 if (regex.Match(item).Success)
 
 Run runx = new Run(item);
 runx.Background = Brushes.Blue;
 tb.Inlines.Add(runx);
 
 else
 
 tb.Inlines.Add(item);
 
 
 
 
 
 
 
 
 

To Filter the rows

private void FilterGrid()
 
 if (dataGrid.ItemsSource != null)
 
 string query = "";
 foreach (CheckBox checkbox in SearchColumns)
 
 if (checkbox.IsChecked == true)
 
 // to check if its the first columns and form the appropriate filter query ;)
 if (query == "")
 query = $"Convert([checkbox.Content], System.String) LIKE '%SearchText%'";
 else
 query += $" or Convert([checkbox.Content], System.String) LIKE '%SearchText%'";
 
 
 (dataGrid.ItemsSource as DataView).RowFilter = query;
 

 

To get each cell of a datagrid i followed this link https://social.msdn.microsoft.com/Forums/vstudio/en-US/9a1872d9-a50b-4bf3-81fc-db0ac4a26d1c/search-in-a-datagridlistview-and-highlight-text?forum=wpf

 public DataGridCell GetCell(int row, int column)
 
 DataGridRow rowContainer = GetRow(row);

 if (rowContainer != null)
 
 DataGridCellsPresenter presenter = GetVisualChild<DataGridCellsPresenter>(rowContainer);

 DataGridCell cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
 if (cell == null)
 
 dataGrid.ScrollIntoView(rowContainer, dataGrid.Columns[column]);
 cell = (DataGridCell)presenter.ItemContainerGenerator.ContainerFromIndex(column);
 
 return cell;
 
 return null;
 

 public DataGridRow GetRow(int index)
 
 DataGridRow row = (DataGridRow)dataGrid.ItemContainerGenerator.ContainerFromIndex(index);
 if (row == null)
 
 dataGrid.UpdateLayout();
 dataGrid.ScrollIntoView(dataGrid.Items[index]);
 row = (DataGridRow)dataGrid.ItemContainerGenerator.ContainerFromIndex(index);
 
 return row;
 


 public static T GetVisualChild<T>(Visual parent) where T : Visual
 
 T child = default(T);
 int numVisuals = VisualTreeHelper.GetChildrenCount(parent);
 for (int i = 0; i < numVisuals; i++)
 
 Visual v = (Visual)VisualTreeHelper.GetChild(parent, i);
 child = v as T;
 if (child == null)
 
 child = GetVisualChild<T>(v);
 
 if (child != null)
 
 break;
 
 
 return child;