I have a ComboBox (ToolStripCombobox, to be more precise) filled with items of type KeyValuePair<Int32, FontFamily>. I managed to have the Items beeing painted manually by using the DrawItem event. So every Item is painted with the FontFamily of the corresponding KeyValuePair. This works fine for the DropDownList, but when I select an Item out of the List and the list closes, the text in the ComboBox says something like "[21, [FontFamily: Name=Arial]]" which is most likely the result of SelectedItem.ToString().
Any ideas how to solve this problem?
here is the code of my custom DrawItem method:
private void fontComboBoxDrawItem(object sender, DrawItemEventArgs e)
{
e.DrawBackground();
if ((e.State & DrawItemState.Focus) != 0)
{
e.DrawFocusRectangle();
}
Brush objBrush = null;
var itemToDraw = this.fontComboBox.Items[e.Index];
KeyValuePair<Int32, FontFamily> windowsFontItem = (KeyValuePair<Int32, FontFamily>)itemToDraw;
objBrush = new SolidBrush(e.ForeColor);
e.Graphics.DrawString(windowsFontItem.Value.Name, new Font(windowsFontItem.Value, e.Font.Size), objBrush, e.Bounds);
if (objBrush != null)
{
objBrush.Dispose();
}
objBrush = null;
}
Update:
It works as expected, when I set the DropDownStyle of the ComboBox to ComboBoxStyle.DropDownList
But I´d rather use ComboBoxStyle.DropDown, so you can edit the Text to search for Fonts.
Related
When my datagrid loads up I am able to get the focus of the first row by providing selected index=0 in the xaml but when I perform searching the focus gets lost so I want focus to be retain at the first row no matter I do sorting and searching on the datagrid.
Here is my code that searches particular thing in the datagrid.
private void TextBox_TextChanged(object sender, RoutedEventArgs e)
{
TextBox STB = (TextBox)sender;
this.SearchValue = STB.Text;
//ContentPresenter CP = (ContentPresenter)STB.TemplatedParent;
//DataGridColumnHeader DGCH = (DataGridColumnHeader)CP.TemplatedParent;
//DataGridColumn DGC = DGCH.Column;
//this.ColumnName = DGC.Header.ToString();
this.Datalist.Filter = this.CustomeFilter;
DataGrid dataGrid = this as DataGrid;
dataGrid.CurrentCell = new DataGridCellInfo(
dataGrid.Items[0], dataGrid.Columns[0]);
dataGrid.BeginEdit();
}
In above code I am trying to get the focus of the current cell but all in vain.
private bool CustomeFilter(object item)
{
SymbolData ltpObj = item as SymbolData;
//WpfApplication1.Model.LtpMessage ltpObj = item as WpfApplication1.Model.LtpMessage;
string values = (string)ltpObj.Symbol.ToString();
values = values.ToUpper();
//return values.StartsWith(this.SearchValue.ToString().ToUpper());
if (values.StartsWith(this.SearchValue.ToString().ToUpper()))
{ return true; }
else
return false;
}
You should read this:
How to programmatically select and focus a row or cell in a DataGrid in WPF: https://blog.magnusmontin.net/2013/11/08/how-to-programmatically-select-and-focus-a-row-or-cell-in-a-datagrid-in-wpf/
You can select and focus a row or cell of a DataGrid programmatically and get the same behaviour as when using the mouse by accessing the visual user interface elements of the DataGrid control and calling the UIElement.Focus() method on a particular DataGridCell object as described in the blog post above. There are code samples included.
You cannot simply set the SelectedItem or SelectedIndex property of the DataGrid to focus the row or cell though.
In my WPF application I have one datagrid and one textbox. In the textChanged event of the textbox, I put this:
myDatagrid.ItemsSource =
myListOfObjects.Where(item => item.Name.Contains(MyTextBox.Text)); //Filter
if (myDatagrid.Items.Count > 0) // If no itens, then do nothing
{
myDatagrid.SelectedIndex = 0; // If has at least one item, select the first
}
myDatagrid.Items.Refresh();
Note that I force the selection when the text changes, in the first row of the DataGrid.
But unfortunately, the color of the row does not change to blue, making it hard to see the selection.
I realy need this, because in the PreviewKeyDown event of the textbox I have this:
private void myTextBox_PreviewKeyDown(object sender, KeyEventArgs e)
{
if (e.Key == Key.Up)
{
if (!(myDataGrid.SelectedIndex <= 0))
{
myDataGrid.SelectedIndex--; // Go one position Up
}
}
if (e.Key == Key.Down)
{
if (!(myDataGrid.SelectedIndex == myDataGrid.Items.Count - 1))
{
myDataGrid.SelectedIndex++; // Go one position Down
}
}
}
So, when the textbox is focused and the user press the Up or the Down key, the selection does not appear to change.
Any idea of how I can make the selected item on the datagrid change it's color to blue?
Other thing: in my virtual machine, it works!! With the same code! How it's possible?
I think that is the aeroglass, but I change the theme to the Windows 7 Basic (same in the virtual machine) and still don't work.
Thanks, and sorry for my english.
Could you try using SelectedItem? you could always create a new property and bind to this and then set this item directly rather than using the selected index. Hopefully this would trigger any additional logic in the DataGrid control :)
//Declare property outside of method
public ObjectType SelectedItem { get; set; }
//Set datacontext on load
DataContext = this;
myDatagrid.ItemsSource = myListOfObjects.Where(item => item.Name.Contains(MyTextBox.Text)); //Filter
if (myDatagrid.Items.Count > 0) // If no itens, then do nothing
{
SelectedItem = myDatagrid.ItemSource[0]; // If has at least one item, select the first
}
myDatagrid.Items.Refresh();
Also don't forget to set your binding!
SelectedItem="{Binding SelectedItem}"
hope that helps!
I have Datagrid and Text Box in my Form. Datagrid is showing me existing items in my stock. I use Text Box to search and set focus to that row which is matching with my Text Box. Now it is working fine when VirtualizingStackPanel.IsVirtualizing="false" but it is very slow and getting a lot RAM resource.
Here is my code for this.
public IEnumerable<Microsoft.Windows.Controls.DataGridRow> GetDataGridRows(Microsoft.Windows.Controls.DataGrid grid)
{
var itemsSource = grid.ItemsSource as IEnumerable;
if (null == itemsSource) yield return null;
foreach (var item in itemsSource)
{
var row = grid.ItemContainerGenerator.ContainerFromItem(item) as Microsoft.Windows.Controls.DataGridRow;
if (null != row) yield return row;
}
}
private void SearchBoxDataGrid_TextChanged(object sender, TextChangedEventArgs e)
{
var row = GetDataGridRows(AssortDataGrid);
/// go through each row in the datagrid
foreach (Microsoft.Windows.Controls.DataGridRow r in row)
{
DataRowView rv = (DataRowView)r.Item;
// Get the state of what's in column 1 of the current row (in my case a string)
string t = rv.Row["Ассортимент"].ToString().ToLower();
if (t.StartsWith(SearchBoxDataGrid.Text.ToLower()))
{
AssortDataGrid.SelectedIndex = r.GetIndex();
AssortDataGrid.ScrollIntoView(AssortDataGrid.SelectedItem);
break;
}
}
}
What I want is to make it VirtualizingStackPanel.IsVirtualizing="true" but in this case my method is not working. I know why it is not working, my code will work only for showing part of Datagrid.
What do you recommend? How to fix this issue? Any idea will be appreciated. If you give any working code it will be fantastic. I hope I could explain my problem.
Virtualization means that WPF will reuse the UI components, and simply replace the DataContext behind the components.
For example, if your Grid has 1000 items and only 10 are visible, it will only render around 14 UI items (extra items for scroll buffer), and scrolling simply replaces the DataContext behind these UI items instead of creating new UI elements for every item. If you didn't use Virtualization, it would create all 1000 UI items.
For your Search to work with Virutalization, you need to loop through the DataContext (DataGrid.Items) instead of through the UI components. This can either be done in the code-behind, or if you're using MVVM you can handle the SeachCommand in your ViewModel.
I did a little coding and make it work. If anyone needs it in future please, use it.
Firstly I am creating List of Products
List<string> ProductList;
Then on Load Method I list all my products to my Product List.
SqlCommand commProc2 = new SqlCommand("SELECT dbo.fGetProductNameFromId(ProductID) as ProductName from Assortment order by ProductName desc", MainWindow.conn);
string str2;
SqlDataReader dr2 = commProc2.ExecuteReader();
ProductList = new List<string>();
try
{
if (dr2.HasRows)
{
while (dr2.Read())
{
str2 = (string)dr2["ProductName"];
ProductList.Insert(0, str2.ToLower ());
}
}
}
catch (Exception ex)
{
MessageBox.Show("An error occured while trying to fetch data\n" + ex.Message);
}
dr2.Close();
dr2.Dispose();
After that I did some changes in SearchBoxDataGrid_TextChanged
private void SearchBoxDataGrid_TextChanged(object sender, TextChangedEventArgs e)
{
int pos = 0;
string typedString = SearchBoxDataGrid.Text.ToLower();
foreach (string item in ProductList)
{
if (!string.IsNullOrEmpty(SearchBoxDataGrid.Text))
{
if (item.StartsWith(typedString))
{
pos = ProductList.IndexOf(item);
AssortDataGrid.SelectedIndex = pos;
AssortDataGrid.ScrollIntoView(AssortDataGrid.SelectedItem);
break;
}
}
}
}
Now it works when VirtualizingStackPanel.IsVirtualizing="true".
That is all.
I have a WPF DataGrid control with a SelectionUnit of "FullRow" and SelectionMode of "Extended" that I'm programmatically selecting an item in (the first item, usually). The selection works, but for some reason any form of programmatic selection seems to break the shift-select multiselect ability.
If I single click another item in the DataGrid (so the item I just clicked is the only item selected), then shift-select will work. It only seems to break if I've programmatically selected the item. Additionally, control-click works to select multiple items in either case -- it seems to only be shift-select that is broken.
I've tried various forms of programmatically selecting the single item, from as simple as myGrid.SelectedIndex = 0, to using the DataGrid's ItemContainerGenerator to get an instance of the DataGridRow object and setting IsSelected = true on it, but to no avail.
To re-iterate -- programmatic selection of an item works, but it breaks shift-click selection.
Has anyone run into this before? I've tried setting focus on the DataGridRow instance that is programmatically selected, but it doesn't seem to help?
I succeeded to work around this problem using reflection:
var method = typeof(DataGrid).GetMethod("HandleSelectionForCellInput", BindingFlags.Instance | BindingFlags.NonPublic);
method.Invoke(MyDataGrid, new object[] { cellToSelect, false, false, false });
I struggled with this problem for multiple days and tried a lot of things that I found on the internet. In the end, I found the solution that works for me by studying the source code of the DataGrid.
In the DataGrid I noticed a member variable called _selectionAnchor and guessed that this must be the starting point for when a user expands the selection in the grid. My solution is to set this member to the first cell of the row that is selected. If a row is selected in code, than this fix makes sure that when expanding the selection it starts at the selected row.
Please note that I used the code from this issue to enable multiselect. Then, in file MainWindow.xaml.cs, I added this code:
private void ExampleDataGrid_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (ExampleDataGrid.SelectedItems.Count > 0)
{
ExampleDataGrid.ScrollIntoView(ExampleDataGrid.SelectedItems[0]);
// Make sure that when the user starts to make an extended selection, it starts at this one
foreach (var cellInfo in ExampleDataGrid.SelectedCells)
{
if (cellInfo.Column.DisplayIndex == 0)
{
var cell = GetDataGridCell(cellInfo);
cell?.Focus();
var field = typeof(DataGrid).GetField("_selectionAnchor", BindingFlags.NonPublic | BindingFlags.Instance);
field?.SetValue(ExampleDataGrid, cellInfo);
break;
}
}
}
}
public DataGridCell GetDataGridCell(DataGridCellInfo cellInfo)
{
var cellContent = cellInfo.Column.GetCellContent(cellInfo.Item);
if (cellContent != null)
{
return (DataGridCell)cellContent.Parent;
}
return null;
}
In the xaml file:
<vm:CustomDataGrid x:Name="ExampleDataGrid" ItemsSource="{Binding ImportItems}"
SelectedItemsList="{Binding SelectedImportItems, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}"
AutoGenerateColumns="False" SelectionMode="Extended" IsReadOnly="True" CanUserAddRows="False"
SelectionChanged="ExampleDataGrid_SelectionChanged">
Remember there is a difference between focus and keyboard focus. When you select the item in code, check to see what control has Keyboard focus / regular focus. I'm guessing that the data grid loses this focus until you click on it with the mouse and then it regains the focus needed to use the ctrl function.
I ran into this issue in a WPF user control we were hosting inside a C++ application.
I just resolved exactly the same problem with the help of #ezolotko's snippet.
Because the grid is dynamically generating rows I needed to subscribe to ItemContainerGenerator.StatusChanged event and find the first cell in a row representing this element.
To find the cell I used DataGridHelper class and wrapped it all in an attached behaviour:
using System.Reflection;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using Speedwell.WPF.Helpers;
namespace Speedwell.WPF.Behaviors
{
public static class DataGridSingleRowSelected
{
public static readonly DependencyProperty IsSelectionFixEnabledProperty = DependencyProperty.RegisterAttached
(
"IsSelectionFixEnabled",
typeof(bool?),
typeof(DataGridSingleRowSelected),
new PropertyMetadata(null, IsSelectionFixEnabledChanged)
);
public static bool GetIsSelectionFixEnabled(DataGrid element)
{
return (bool)element.GetValue(IsSelectionFixEnabledProperty);
}
public static void SetIsSelectionFixEnabled(DataGrid element, bool value)
{
element.SetValue(IsSelectionFixEnabledProperty, value);
}
private static void IsSelectionFixEnabledChanged(DependencyObject sender, DependencyPropertyChangedEventArgs args)
{
var dataGrid = sender as DataGrid;
if(dataGrid != null)
{
if(args.OldValue == null)
{
dataGrid.ItemContainerGenerator.StatusChanged += (s, e) => ContainerStatusChanged(dataGrid, ((ItemContainerGenerator)s));
}
}
}
private static void ContainerStatusChanged(DataGrid dataGrid, ItemContainerGenerator generator)
{
if(generator != null && generator.Status == GeneratorStatus.ContainersGenerated && dataGrid.SelectedItems.Count == 1)
{
var row = (DataGridRow)dataGrid.ItemContainerGenerator.ContainerFromItem(dataGrid.SelectedItems[0]);
if(row != null)
{
var cell = dataGrid.GetCell(row, 0);
if(cell != null)
{
SelectCellMethod.Invoke(dataGrid, new object[] { cell, false, false, false });
}
}
}
}
private static readonly MethodInfo SelectCellMethod = typeof(DataGrid).GetMethod("HandleSelectionForCellInput", BindingFlags.Instance | BindingFlags.NonPublic);
}
}
As you can see the proper selection is only applied when there is a single (1) row selected and this is exactly what I need and it seems it also what #Jordan0Day requested.
I have a WPF Datagrid and I'm implementing drag and drop functionality.
The datagrid has a list of "files" and the user can drag them and copy the file to the desktop.
This is done like this:
string[] files = new String[myDataGrid.SelectedItems.Count];
int ix = 0;
foreach (object nextSel in myDataGrid.SelectedItems)
{
files[ix] = ((Song)nextSel).FileLocation;
++ix;
}
string dataFormat = DataFormats.FileDrop;
DataObject dataObject = new DataObject(dataFormat, files);
DragDrop.DoDragDrop(this.myDataGrid, dataObject, DragDropEffects.Copy);
I have two questions:
1. When I want to drag multiple items- this is a problem because after I select a couple and start clicking on one to start dragging- only that gets selected and the other items get deselected. I tried the solution that is given here but for some reason it doesn't work.
2. I want to remove the dragged item from the datagrid after it is copied. The problem is that I don't know how to check if the file was copied or whether the user just dragged it on the screen without copying it.
I hope you can help me solve these problems.
Thanks!
I think this i what you are looking for:
add this code to the DataGrid__PreviewMouseLeftButtonDown event handler:
private void DataGrid_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
this.startingPosition = e.GetPosition(null);
DependencyObject dep = (DependencyObject)e.OriginalSource;
// iteratively traverse the visual tree until get a row or null
while ((dep != null) && !(dep is DataGridRow))
{
dep = VisualTreeHelper.GetParent(dep);
}
//if this is a row (item)
if (dep is DataGridRow)
{
//if the pointed item is already selected do not reselect it, so the previous multi-selection will remain
if (songListDB.SelectedItems.Contains((dep as DataGridRow).Item))
{
// now the drag will drag all selected files
e.Handled = true;
}
}
}
and now the draging won't change you selection.
Have a good luck!
I used that article to write my answer
Improved on finding the row.
Also selecting the clicked row when not dragging is added.
This now behaves exactly as other Microsoft selectors (eg Outlook)
public TreeDataGrid()
{
Loaded += TreeDataGrid_Loaded;
LoadingRow += new EventHandler<DataGridRowEventArgs>(TreeDataGrid_LoadingRow);
}
#region MultiSelect Drag
object toSelectItemOnMouseLeftButtonUp;
void TreeDataGrid_LoadingRow(object sender, DataGridRowEventArgs e)
{
e.Row.PreviewMouseLeftButtonDown += new MouseButtonEventHandler(Row_PreviewMouseLeftButtonDown);
e.Row.PreviewMouseLeftButtonUp += new MouseButtonEventHandler(Row_PreviewMouseLeftButtonUp);
}
void Row_PreviewMouseLeftButtonDown(object sender, MouseButtonEventArgs e)
{
DataGridRow row = (DataGridRow)sender;
toSelectItemOnMouseLeftButtonUp = null; // always clear selecteditem
if (SelectedItems.Contains(row.Item)) //if the pointed item is already selected do not reselect it, so the previous multi-selection will remain
{
e.Handled = true; // this prevents the multiselection from disappearing, BUT datagridcell still gets the event and sets DataGrid's private member _selectionAnchor
toSelectItemOnMouseLeftButtonUp = row.Item; // store our item to select on MouseLeftButtonUp
}
}
void Row_PreviewMouseLeftButtonUp(object sender, MouseButtonEventArgs e)
{
DataGridRow row = (DataGridRow)sender;
if (row.Item == toSelectItemOnMouseLeftButtonUp) // check if it's set and concerning the same row
{
if (SelectedItem == toSelectItemOnMouseLeftButtonUp) SelectedItem = null; // if the item is already selected whe need to trigger a change
SelectedItem = toSelectItemOnMouseLeftButtonUp; // this will clear the multi selection, and only select the item we pressed down on
typeof(DataGrid).GetField("_selectionAnchor", BindingFlags.Instance | BindingFlags.NonPublic).SetValue(this, new DataGridCellInfo(row.Item, ColumnFromDisplayIndex(0))); // we need to set this anchor for when we select by pressing shift key
toSelectItemOnMouseLeftButtonUp = null; // handled
}
}
#endregion