WPF Datagrid: Programmatically editing a cell

c#, datagrid, wpf

Solution

not sure if I'm understanding your question correctly; it looks like you want to access and change the DataGridCell content programmatically. Pls check an example below; I've added a SelectedCellsChanged even hander to the datagrid, it should be triggered every time new cell(s) is selected; having the DataGridCellInfo object you can get access to the DataGridCell object and change its Content.

private void dataGrid1_SelectedCellsChanged(object sender, SelectedCellsChangedEventArgs e)
{
    foreach (DataGridCellInfo cellInfo in dataGrid1.SelectedCells)
    {
        // this changes the cell's content not the data item behind it
        DataGridCell gridCell = TryToFindGridCell(dataGrid1, cellInfo);
        if (gridCell!=null) gridCell.Content = "changed!!!"; 
    }
}

static DataGridCell TryToFindGridCell(DataGrid grid, DataGridCellInfo cellInfo)
{
    DataGridCell result = null;
    DataGridRow row = (DataGridRow)grid.ItemContainerGenerator.ContainerFromItem(cellInfo.Item);
    if (row!=null)
    {
        int columnIndex = grid.Columns.IndexOf(cellInfo.Column);
        if (columnIndex>-1)
        {
            DataGridCellsPresenter presenter = GetVisualChild<DataGridCellsPresenter>(row);
            result = presenter.ItemContainerGenerator.ContainerFromIndex(columnIndex) as DataGridCell;
        }
    }
    return result;
}

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;
}

code of GetVisualChild is taken from here

hope it's going to help you, also you maight want to take a look at the BeginEdit of a specific Cell from code behind question on SO. I guess it can also give you some ideas

regards

Problem

I have a cell that needs its value to be set on it just being clicked. It is multibound to different properties. Where am I supposed to do this? I have been trying to do it in the datagrid beginingedit handler like this (without much success). I am able to manually click twice(once to select cell and then to start edit) and the value gets set. But I want to do this programmatically... ``` private void MyDataGrid_BeginningEdit(object sender, DataGridBeginningEditEventArgs e) { TextBlock t = e.EditingEventArgs.OriginalSource as TextBlock; if (t == null) return; t.Text = SimulatedEdit(); // All this below is just me trying different thing. Not sure what I need to be doing e.EditingEventArgs.Handled = true; MyDataGrid.CommitEdit(); MyDataGrid.UnselectAllCells(); } ``` This is how the columntemplate is setup ``` MultiBinding tempmb = new MultiBinding(); Binding tempXB = new Binding("X"); Binding temptYB = new Binding("Y"); tempmb.Bindings.Add(tempXB); tempmb.Bindings.Add(temptYB); tempmb.ConverterParameter = "ggrid"; tempmb.Converter = new LabelDecider(); DataGridTemplateColumn dgtc = new DataGridTemplateColumn { Header = "blah", CanUserSort = false, CanUserReorder = false, }; DataTemplate t = new DataTemplate(); FrameworkElementFactory f = new FrameworkElementFactory(typeof(TextBlock)); f.SetBinding(TextBlock.TextProperty, tempmb); // Setup background color binding MultiBinding colorb = new MultiBinding(); colorb.Bindings.Add(tempX); colorb.Bindings.Add(tempY); colorb.ConverterParameter = "color"; colorb.Converter = new LabelDecider(); f.SetBinding(TextBlock.BackgroundProperty, colorb); t.VisualTree = f; //Every columns Text and Background are using bindings dgtc.CellTemplate = t; //setup editing template DataTemplate ced = new DataTemplate(); FrameworkElementFactory f2 = new FrameworkElementFactory(typeof(TextBox)); MultiBinding tempmb2 = new MultiBinding(); tempmb2.Bindings.Add(tempXB); tempmb2.Bindings.Add(tempYB); tempmb2.Mode = BindingMode.TwoWay; tempmb2.ConverterParameter = "ggrid"; tempmb2.Converter = new LabelDecider(rDestination.Recievers[k]); tempmb2.UpdateSourceTrigger = UpdateSourceTrigger.LostFocus; f2.SetBinding(TextBox.TextProperty, tempmb2); ced.VisualTree = f2; dgtc.CellEditingTemplate = ced; MyDataGrid.Columns.Add(dgtc); ```

Original source