I have a listview that I would like to add a textbox inside each gridview column cell so I can type data into it and then fetch that data.
I'm creating a datatemplate and passing it to a cell template for the GridViewColumn but when I look at the listview I can't add anything to the cell. It doesn't look like the textbox was even created.
GridViewColumn conceptColumn = new GridViewColumn();
conceptColumn.Header = conceptName;
conceptColumn.CellTemplate = this.GetDataTemplate();
this.TestModeler.Columns.Add(conceptColumn);
conceptColumn.DisplayMemberBinding = new Binding(conceptName);
private DataTemplate GetDataTemplate()
{
DataTemplate dt = new DataTemplate(typeof(TextBox));
FrameworkElementFactory txtElement = new FrameworkElementFactory(typeof(TextBox));
dt.VisualTree = txtElement;
Binding bind = new Binding();
bind.Path = new PropertyPath("Text");
bind.Mode = BindingMode.TwoWay;
txtElement.SetBinding(TextBox.TextProperty, bind);
txtElement.SetValue(TextBox.TextProperty, "test");
return dt;
}
Please take a look at the ListView Class page at MSDN where you can find a XAML example and plenty of link on how to do various things with a WPF ListView.
Of particular interest to you, please take a look at the How to: Use Templates to Style a ListView That Uses GridView page there which explains what you are trying to do (but in XAML) with examples.
MSDN should always be your first place to look as it is full of information just waiting to be read.
Related
I have to show a set of data in a DataGrid having columns style as ComboBox or TextBlock.
The DataGrid is binded to a DataTable.
The number and position of each column in the DataTable is defined at runtime, so I create the DataGrid programmatically.
Everything is fine as long as I use DataGridTextColumn and leave the default style (TextBlock), while I get a type error if I try to change the DataGridTextColumn to TextBox style.
There is no problem for what concerns ComboBox, so I paste hereafter only the DataGridTextColumn part of my code (for a single DataGrid cell):
C#
// Create the DataTable that will contain real-time data
public DataTable CurrentTable { get; set; }
// Binding string
string stringA = "some_string_A";
// Create new binding
Binding b = new Binding(stringA);
b.Mode = BindingMode.TwoWay;
// Create a new TextColumn
DataGridTextColumn dgCol = new DataGridTextColumn();
//dgCol.ElementStyle = new Style(typeof(TextBox)); <- this row generates error
// Set the column binding for the new TextColumn
dgCol.Binding = b;
// Add the TextColumn to the DataGrid
datagrid.Columns.Add(dgCol);
// Create a new row in the DataTable
var colDataTable = CurrentTable.NewRow();
// Populate column "stringA" of the new row
colDataTable[stringA]="some_string_B";
// Add the row to DataTable
CurrentTable.Rows.Add(colDataTable);
// Finally bind DataGrid to DataTable
datagrid.ItemsSource = CurrentTable.AsDataView();
XAML
<DataGrid x:Name="datagrid" ItemsSource="{Binding CurrentTable}" CanUserAddRows="True" />
I tried to change the column style to TetBox in many ways, probably I misunderstood something, could anybody enlight me?
You should the EditingElementStyle property to your TextBox style:
dgCol.EditingElementStyle = new Style(typeof(TextBox));
A DataGridTextColumn has two styles. One for displaying and another one for editing.
I'm using a WPF DataGrid to display DataTable's.
I need to be able to edit this bound DataTables (Two-Way Binding).
I'm using the DataGrid as followed:
<DataGrid SelectionUnit="CellOrRowHeader" IsReadOnly="False" AutoGenerateColumns="True" ItemsSource="{Binding Path=SelectedItem.BindableContent, FallbackValue={x:Null}}" />
The Problem I have, the user can't edit the ColumnHeader's like cell content or rows.
The Screenshot below illustrates that porblem. The only thing I can do is sort the columns.
Is there a way to edit the column headers too, for example when the user clicks twice, or presses F2.
Maybe some Style' or a HeaderTemplate will do the job? I have already tried some styles and control templates I've found around the internet, but without any success.
EDIT:
I managed to display the column headers in a TextBox (and not in a TextBlock) within the AutogeneratingTextcolumn event handler:
private void _editor_AutoGeneratingColumn(object sender, DataGridAutoGeneratingColumnEventArgs e) {
// First: create and add the data template to the parent control
DataTemplate dt = new DataTemplate(typeof(TextBox));
e.Column.HeaderTemplate = dt;
// Second: create and add the text box to the data template
FrameworkElementFactory txtElement =
new FrameworkElementFactory(typeof(TextBox));
dt.VisualTree = txtElement;
// Create binding
Binding bind = new Binding();
bind.Path = new PropertyPath("Text");
bind.Mode = BindingMode.TwoWay;
// Third: set the binding in the text box
txtElement.SetBinding(TextBox.TextProperty, bind);
txtElement.SetValue(TextBox.TextProperty, e.Column.Header);
}
But I couldn't manage to set the binding correctly, if i edit the Text in the TextBoxes, it does not change the text in the Column.Header-Property (which is auto-generated by a binding to a DataTable like explained above).
You forgot to set the source of your binding and you mustn't set the value after the registration of the binding. The correct code would be the following:
private void asdf_AutoGeneratingColumn(object sender, DataGridAutoGeneratingColumnEventArgs e)
{
DataTemplate dt = new DataTemplate(typeof(TextBox));
e.Column.HeaderTemplate = dt;
FrameworkElementFactory txtElement =
new FrameworkElementFactory(typeof(TextBox));
dt.VisualTree = txtElement;
Binding bind = new Binding();
bind.Path = new PropertyPath("Header");
bind.Mode = BindingMode.TwoWay;
// set source here
bind.Source = e.Column;
txtElement.SetBinding(TextBox.TextProperty, bind);
// You mustn't set the value here, otherwise the binding doesn't work
// txtElement.SetValue(TextBox.TextProperty, e.Column.Header);
}
Additionally you must change the binding property to Header, because you are adding the binding to the text property of the TextBox.
Short and simple question. In Winforms you can bind a dataview to a combobox or some other control by simply:
combobox.DataSource = dataview
combobox.DisplayMember = "Something"
In WPF I've generally done databinding using an ObservableCollection and edits to the xaml. Is there a way to quickly do it, like the above?
Edit:
This seems to be the simplest/quickest thing I can come up with, anything inherently wrong with it?
combobox.ItemSource = dataview
combobox.DisplayMemberPath = "Something"
You can set binding programmatically, although, per my understanding of the MVVM pattern, the best practice is to set binding in the View (xaml) not the ViewModel or View code-behind.
How to set binding programmatically:
Binding myBinding = new Binding("Name");
myBinding.Source = dataview // data source from your example
combobox.DisplayMemberPath = "Something"
combobox.SetBinding(ComboBox.ItemsSourceProperty, myBinding);
With this, when your dataview is updated, the updates will be shown in your ComboBox.
You can do this:
List<Person> someListOFPersons = new List<Person>();
comboBox.DataContext = someListOfPersons;
comboBox.DisplayMemberPath = "FirstName";
You will not see changes in the collection. So if a person is added to or removed from the list the combobox will not see it.
I use a listview to display data like a data matrix (columns and rows). My problem is : my items are typed : MatrixCellVM.
I tried everything I found on the net to apply a DataTemplate on this items but nothing worked.
Here is the latest technique I'm using
foreach (var col in dataMatrix.Columns)
{
//create the data template
DataTemplate cellLayout = new DataTemplate();
cellLayout.DataType = typeof(MatrixCellVM);
//set up the stack panel
FrameworkElementFactory spFactory = new FrameworkElementFactory(typeof(Grid));
spFactory.Name = "myComboFactory";
//set up value textblock
FrameworkElementFactory cellValue = new FrameworkElementFactory(typeof(TextBlock));
cellValue.SetBinding(TextBlock.TextProperty, new Binding("Value"));
cellValue.SetValue(TextBlock.ToolTipProperty, "Value");
spFactory.AppendChild(cellValue);
//set the visual tree of the data template
cellLayout.VisualTree = spFactory;
gridView.Columns.Add(new GridViewColumn{
Header = col.Name,
DisplayMemberBinding = new Binding(string.Format("[{0}]", count)),
CellTemplate = cellLayout
});
count++;
}
One more thing, when I override ToString() in MatrixCellVM, the value is displayed (but with this technique I add a context menu or give any color to my value).
I solved the problem but have another one.
So what I did is pretty simple. DisplayMemberBinding and CellTemplate can't be put together.
So I deleted the whole c# code creating the datatemplate.
The only thing that remains is :
gridView.Columns.Add(
new GridViewColumn
{
Header = col.Name,
CellTemplate = (DataTemplate)listView.Resources["MatrixCellVMTemplate"]
});
Thus, I added in my xaml code defining the datatemplate.
My new problem is that my rows are arrays of MatrixCellVM (as it is a matrix, I don't have properties and I don't know by advance how many columns I will have).
That was the point of the DisplayMemberBinding = new Binding(string.Format("[{0}]",count)) code in my top post.
How could I reproduce this behavior in my datatemplate (what is the binding in my textblock).
If anything is not clear, let me know.
Thanks
At run time I want to dynamically build grid columns (or another display layout) in a WPF ListView. I do not know the number and names of the columns before hand.
I want to be able to do:
MyListView.ItemSource = MyDataset;
MyListView.CreateColumns();
You can add columns dynamically to a ListView by using Attached Properties. Check out this article on the CodeProject it explains exactly that...
WPF DynamicListView - Binding to a DataMatrix
From MSDN:
MyListBox.ItemsSource = view;
ListView myListView = new ListView();
GridView myGridView = new GridView();
myGridView.AllowsColumnReorder = true;
myGridView.ColumnHeaderToolTip = "Employee Information";
GridViewColumn gvc1 = new GridViewColumn();
gvc1.DisplayMemberBinding = new Binding("FirstName");
gvc1.Header = "FirstName";
gvc1.Width = 100;
myGridView.Columns.Add(gvc1);
GridViewColumn gvc2 = new GridViewColumn();
gvc2.DisplayMemberBinding = new Binding("LastName");
gvc2.Header = "Last Name";
gvc2.Width = 100;
myGridView.Columns.Add(gvc2);
GridViewColumn gvc3 = new GridViewColumn();
gvc3.DisplayMemberBinding = new Binding("EmployeeNumber");
gvc3.Header = "Employee No.";
gvc3.Width = 100;
myGridView.Columns.Add(gvc3);
//ItemsSource is ObservableCollection of EmployeeInfo objects
myListView.ItemsSource = new myEmployees();
myListView.View = myGridView;
myStackPanel.Children.Add(myListView);
i'd try following approach:
A) you need to have the list box display grid view - i believe this you've done already
B) define a style for GridViewColumnHeader:
<Style TargetType="{x:Type GridViewColumnHeader}" x:Key="gridViewColumnStyle">
<EventSetter Event="Click" Handler="OnHeaderClicked"/>
<EventSetter Event="Loaded" Handler="OnHeaderLoaded"/>
</Style>
in my case, i had a whole bunch of other properties set, but in the basic scenario - you'd need Loaded event. Clicked - this is useful if you want to add sorting and filtering functionality.
C) in your listview code, bind the template with your gridview:
public MyListView()
{
InitializeComponent();
GridView gridViewHeader = this.listView.View as GridView;
System.Diagnostics.Debug.Assert(gridViewHeader != null, "Expected ListView.View should be GridView");
if (null != gridViewHeader)
{
gridViewHeader.ColumnHeaderContainerStyle = (Style)this.FindResource("gridViewColumnStyle");
}
}
D) then in you OnHeaderLoaded handler, you can set a proper template based on the column's data
void OnHeaderLoaded(object sender, RoutedEventArgs e)
{
GridViewColumnHeader header = (GridViewColumnHeader)sender;
GridViewColumn column = header.Column;
//select and apply your data template here.
e.Handled = true;
}
E) I guess you'd need also to acquire ownership of ItemsSource dependency property and handle it's changed event.
ListView.ItemsSourceProperty.AddOwner(typeof(MyListView), new PropertyMetadata(OnItemsSourceChanged));
static void OnItemsSourceChanged(DependencyObject sender, DependencyPropertyChangedEventArgs e)
{
MyListView view = (MyListView)sender;
//do reflection to get column names and types
//and for each column, add it to your grid view:
GridViewColumn column = new GridViewColumn();
//set column properties here...
view.Columns.Add(column);
}
the GridViewColumn class itself doesn't have much properties, so you might want to add some information there using attached properties - i.e. like unique column tag - header most likely will be used for localization, and you will not relay on this one.
In general, this approach, even though quite complicated, will allow you to easily extend your list view functionality.
Have a DataTemplateselector to select one of the predefined templates(Of same DataType) and apply the selector on to the ListView. You can have as many DataTemplates with different columns.
You can use a DataTemplateSelector to return a DataTemplate that you have created dynamically in code. However, this is a bit tedious and more complicated than using a predefined one from XAML, but it is still possible.
Have a look at this example: http://dedjo.blogspot.com/2007/03/creating-datatemplates-from-code.html
From experience I can recommend steering clear of dynamic data templates if you can help it... rather use the advice given here to explictly create the ListView columns, rather than trying to create a DataTemplate dynamically.
Reason is that the FrameworkElementFactory (or whatever the class name is for producing DataTemplates at run time) is somewhat cludgey to use (and is deprecated in favor of using XAML for dynamic templates) - either way you take a performance hit.
This function will bind columns to a specified class and dynamically set header, binding, width, and string format.
private void AddListViewColumns<T>(GridView GvFOO)
{
foreach (System.Reflection.PropertyInfo property in typeof(T).GetProperties().Where(p => p.CanWrite)) //loop through the fields of the object
{
if (property.Name != "Id") //if you don't want to add the id in the list view
{
GridViewColumn gvc = new GridViewColumn(); //initialize the new column
gvc.DisplayMemberBinding = new Binding(property.Name); // bind the column to the field
if (property.PropertyType == typeof(DateTime)) { gvc.DisplayMemberBinding.StringFormat = "yyyy-MM-dd"; } //[optional] if you want to display dates only for DateTime data
gvc.Header = property.Name; //set header name like the field name
gvc.Width = (property.Name == "Description") ? 200 : 100; //set width dynamically
GvFOO.Columns.Add(gvc); //add new column to the Gridview
}
}
}
Let's say you have a GridView with Name="GvFoo" in your XAML, which you would like to bind to a class FOO.
then, you can call the function by passing your class "FOO and GridView "GvFoo" as arguments in your MainWindow.xaml.cs on Window loading
AddLvTodoColumns<FOO>(GvFoo);
your MainWindow.xaml file should include the following
<ListView x:Name="LvFOO">
<ListView.View>
<GridView x:Name="GvTodos"/>
</ListView.View>
</ListView>