I have dynamically created a series of grids and textblocks inside of said grids. However I am having trouble using the .FindName to call the textblock I need. My control heirarchy goes something like this:
Page -> ScrollViewer - > Grid -> Dynamically Created Grids ->
Dynamically Created Controls
This is how I am currently trying to call them and any other ways I attempted have still gotten me no where
Dim grd As Object = FindName("GridLine" + Ri.ToString())
Dim tempgrd As Grid = DirectCast(grd, Grid)
Dim txtID As Object = tempgrd.FindName("txtIDGrid" + Ri.ToString())
Dim tempID As TextBlock = DirectCast(txtID, TextBlock)
sqlID = tempID.Name
In case anyone else is searching for a similar answer I did end up solving it. You must be sure to RegisterName the controls you are creating to ensure that you can call upon it after runtime.
Related
I am programmatically creating a GridViewColumn in WPF as follows:
Dim oGVCol As GridViewColumn = New GridViewColumn
Dim oHeaderTemplate As DataTemplate
oHeaderTemplate = New DataTemplate
Dim oGridFactory As FrameworkElementFactory = New FrameworkElementFactory(GetType(Grid))
oHeaderTemplate.VisualTree = oGridFactory
oGridFactory.SetValue(Grid.BackgroundProperty, Brushes.Transparent)
oGVCol.HeaderTemplate = oHeaderTemplate
(I have removed irrelevant code to set the content of the grid)
What I can't figure out is how to add a "click" event for the GridViewColumnHeader itself. I can add events to the Grid and any other Controls I added through the Factory objects, no problem. But I'm stuck on how to add an event to the header itself.
If you have a solution in VB.NET, great, but C# is fine too.
One (failed) attempt:
AddHandler TryCast(oGVCol.Header, GridViewColumnHeader).Click, AddressOf HeaderClick
Sadly it turns out that I cannot cast oGVCol.Header to a GridViewColumnHeader.
Ok, it may not be pretty, but I found a pretty decent solution to the problem.
Firstly, when I create the Grid Factory for the root element in the header's Visual Tree, I give it a name
oGridFactory.SetValue(Grid.NameProperty, <column name here>))
(Please note that the Names must have only letters, numbers and underscores so if your data contains column names that don't have those, you'll need to deal with that both here, to convert invalid names to valid ones, and below, to revert them back to their original names if necessary.... I won't detail that functionality here)
Also, I add an event handler to the Root "Grid" in the Template for the column header:
oGridFactory.AddHandler(Grid.SizeChangedEvent,
New SizeChangedEventHandler(AddressOf ColumnHeaderSizeChanged))
The "magic" happens in the procedure ColumnHeaderSizeChanged. This procedure is called both when the grid is Rendered the first time, but also when the user is manually resizing columns.
Signature:
Private Sub ColumnHeaderSizeChanged(sender As Object, e As SizeChangedEventArgs)
I keep a List(Of GridViewColumnHeaders) which is reset to an empty list when I need to replace the Grid with a different one. In the ColumnHeaderSizeChanged event I then do the following:
The first thing we need to do is get to the Root of the controls in the Column Header. For example, your column header may contain a TextBlock to show a column name, and icons to indicate it's been sorted up or down. That sort of thing. When the user clicks on the header they may be clicking on any of those controls, so:
Dim oParent As Object
Dim oColHeader As GridViewColumnHeader = Nothing
Dim sColHeaderName As String = String.Empty
Dim oGWH As Grid = Nothing
oParent = e.OriginalSource 'This may be any of the controls in the header.
If Not oParent Is Nothing Then
Try
While Not oParent.Parent Is Nothing
'So we keep going down the Tree until we hit the Root Parent
'which will be the main Grid created in the Grid Factory
oParent = oParent.Parent
End While
Catch
End Try
End If
'But at this point, if we still have a control, it will be the main Grid
If oParent Is Nothing Then
Exit Sub
End If
If TryCast(oParent, Grid) Is Nothing Then
'what the heck is this? This SHOULD be the Grid at the root of the Visual Tree,
'so if, for whatever reason, this is NOT a Grid, get outta here.
Exit Sub
End If
By this point we're on the main Grid, but now we need to get the GridViewColumnHeader into which this Grid has been created. So now we go to the TemplatedParent
While Not oParent.TemplatedParent Is Nothing
oParent = oParent.TemplatedParent
oColHeader = TryCast(oParent, GridViewColumnHeader)
If Not oColHeader Is Nothing Then
'This procedure is called both when the Grid View is first rendered,
'and when the user is dragging the column width.
If Mouse.LeftButton = MouseButtonState.Pressed Then
'Do something appropriate to when the user is resizing the column
Else
'Do something appropriate to when the grid
'is first Rendered or re-displayed
End If
Exit While
End If
End While
At this point we have the GridViewColumnHeader we need, so we can add it to the List and add a Handler for its Click event. moColHeaders is the List(Of GridViewColumnHeaders)
If Not oColHeader Is Nothing Then
If Not moColHeaders.Contains(oColHeader) Then
oColHeader.Name = <column name here>
moColHeaders.Add(oColHeader) 'Only need to add it once!
AddHandler oColHeader.Click, AddressOf HeaderClick
End If
End If
Now you can code your HeaderClick procedure to handle the GridViewColumnHeader.Click event.
Signature:
Private Sub HeaderClick(sender As Object, e As RoutedEventArgs)
I have a code in vb.net to select all buttons in form within flowlayoutpanel, but it returns zero.
I think problem is with flowlayoutpanel.
Dim alphabetButtons() As Button
alphabetButtons = Me.Controls.OfType(Of Button).Except(New Button() {Button1}).ToArray
Can you tell me what am I doing wrong?
I have a code in vb.net to select all buttons in form within flowlayoutpanel, but it returns zero. ... Can you tell me what am I doing wrong?
Yes. You're telling the Form to return all Controls of Type Button:
Dim alphabetButtons() As Button
alphabetButtons = Me.Controls.OfType(Of Button).Except(New Button() {Button1}).ToArray
You need to ask the FlowLayoutPanel this question.
Change Me to the name of your FlowLayoutPanel, such as FlowLayoutPanel1 in the "fixed" code below:
Dim alphabetButtons() As Button
alphabetButtons = FlowLayoutPanel1.Controls.OfType(Of Button).Except(New Button() {Button1}).ToArray
The Controls() collection only returns controls that are directly contained by that container. Each container has its own collection of child controls...
[disclaimer: I am new to Visual Basic.]
In a WPF, I have a TabControl containing 2 TabItems:
The first TabItem contains a bunch of URLs.
The second TabItem consists of a DockPanel that contains a cefSharp webView (chromium embedded for .net)
When I click on a url in tab1 it loads a page in the browser contained in tab2... But, it only works if I have initialized the browser first by clicking on tab2.
After doing some searching, it looks like vb.net doesn't initialize the content in a TabItem until it becomes visible. (right?)
So, my question is, how can I force a non-selected tab to initialize its content on load, in the background? (ie. so I don't have to click on the tab or switch to it first)
EDIT:
As requested, here is the relevant code:
The relevant XAML consists of a single DockPanel named "mainBox"
<DockPanel Name="mainBox" Width="Auto" Height="Auto" Background="#afe0ff" />
And here is my "code behind" vb script:
Class MainWindow : Implements ILifeSpanHandler, IRequestHandler
Shared web_view1 As CefSharp.Wpf.WebView
Shared web_view2 As CefSharp.Wpf.WebView
Public Sub init(ByVal sender As Object, ByVal e As EventArgs) Handles Me.Loaded
'This is in a DockPanel created on the xaml named mainBox
' set up tabControl:
Dim browserTabs As New TabControl()
browserTabs.BorderThickness = Nothing
Dim tab1 As New TabItem()
tab1.Header = "My Tab"
Dim tab2 As New TabItem()
tab2.Header = "Browser"
Dim tab1Content As New DockPanel()
Dim tab2Content As New DockPanel()
tab1.Content = tab1Content
tab2.Content = tab2Content
browserTabs.Items.Add(tab1)
browserTabs.Items.Add(tab2)
mainBox.Children.Add(browserTabs)
' set up browsers:
Dim settings As New CefSharp.Settings()
settings.PackLoadingDisabled = True
If CEF.Initialize(settings) Then
web_view1 = New CefSharp.Wpf.WebView()
web_view1.Name = "myTabPage"
web_view1.Address = "http://stackoverflow.com/"
web_view2 = New CefSharp.Wpf.WebView()
web_view2.Name = "browserPage"
web_view2.Address = "https://www.google.com"
web_view2.LifeSpanHandler = Me
web_view2.RequestHandler = Me
AddHandler web_view2.PropertyChanged, AddressOf web2PropChanged
tab1Content.Children.Add(web_view1)
tab2Content.Children.Add(web_view2)
End If
End Sub
End Class
So, in its default state, tab1 is showing at start up -- the browser on tab2 (web_view2) won't initialize until I click its tab or change to its tab via script. Hope this clears it up a bit.
Your code doesn't use Windows Forms' TabPage but perhaps this might still help
As we know, Controls contained in a TabPage are not created until the
tab page is shown, and any data bindings in these controls are not
activated until the tab page is shown. This is by design and you can
call TabPage.Show() method one by one as a workaround.
via MSDN forums
Also, based on the above idea, have you tried the following.
tab2.isEnabled = True
tab1.isEnabled = True
Or:
tab2.Visibility = True
tab1.Visibility = True
Also, the BeginInit Method might help in your situation.
I had the same problem but found it initializes if I use the name of the tabpage and show (tabName1.show()) on the form load code for each page ending with the one I want displayed:
tabPage2.show()
tabPage3.show()
tabPage4.show()
tabPage5.show()
tabPage1.show()
It ripples thru and you never see the pages changing but it works. The other suggestions didn't work for me in Visual Studio 2010.
I m working with WPF DataGrid and I want to retrieve a DataGridCell's value by using the column and the row indexes : all what I could do is this but it didn't work :
myDatGrid.Columns[0].GetCellContent((DataGridRow)myDatGrid.Items[0]);
Could you please show me the way to realize that
Your cells value is going to be contingent on what the given column is bound to. The entire row will be the instance of your model.
Assume we have a collection of Person classes which we are binding to within our DataGrid.
Person p = ((ContentPresenter)myDatGrid.Columns[0].GetCellContent(myDatGrid.Items[0])).Content;
The Content property is going to return the underlying model for the row. If you wanted to obtain a given property you can do so by directly accessing the underyling object which should implement INotifyPropertyChanged, no need to fool with the DataGrid as you would in a WinForms application.
I tried what has been proposed above and it did not work.
I struggled for a whole day trying to bind a ComboBox and select the correct value in a WPF Datagrid when it first loads, so I thought I would share my solution here in hopes that somebody else could benefit. Sorry about the VB, but the concept should work in C# also.
First, if you are trying to get the values populated and selected when the grid first loads, you need to put your code in the correct event handler: LayoutUpdated. In other event handlers, the GetCellContent function returns Nothing (null). You could also put this code in an event handler which handles an event occurring later, such as a Button.Click event, if that meets your requirements.
Second, the code:
For i As Int32 = 0 To DataGrid1.Items.Count - 1
Dim row As DataGridRow
row = DataGrid1.ItemContainerGenerator.ContainerFromItem(DataGrid1.Items(i))
If row IsNot Nothing AndAlso row.Item IsNot Nothing Then
Dim cp As ContentPresenter = DataGrid1.Columns(3).GetCellContent(DataGrid1.Items(i))
If cp IsNot Nothing AndAlso cp.ContentTemplate IsNot Nothing Then
Dim dt As DataTemplate = cp.ContentTemplate
If dt IsNot Nothing Then
Dim cb As ComboBox = dt.FindName("cbVendorNames", cp)
If cb IsNot Nothing Then
cb.ItemsSource = Vendors
cb.DisplayMemberPath = "VendorName"
cb.SelectedValuePath = "AS_ID"
cb.SelectedValue = "" ' set your selected value here
End If
End If
End If
End If
Next
What this code does is (a) loop through all of the rows in the datagrid, (b) get the ContentPresenter for the cell selected (in this case, cell 3 in each row), (c) get the DataTemplate for the ContentPresenter, and (d) finally, get the reference to the ComboBox. This allowed me to bind the ComboBox to an external datasource (a List(Of Vendor) and select its value. This code worked for me.
I do not find this solution particularly elegant or efficient, but it does work. If somebody has a better solution, please post it.
OK I think I got it , I missed some casts that I should put , because the column I'm using is a DataGridComboBoxColumn
I should actually do this :
((ComboBox)(myDatGrid.Columns[0].GetCellContent(
(TestData)myDatGrid.Items[0]))).SelectedValue.ToString());
Now it works.
I am from VB.Net WinForms comming. Now I wanted to write a small app in WPF, listing some files in a datagridview. I used WPF's DataGrid, created some Columns. And then failed to add my rows.
Please, can you help me to select the right way to get my filenames, state-text and thumbnails added to the DataGrid Row?
In VB.Net WinForms I can add a row like this:
Datagridview1.Rows.add(Myvalue, "RowStateText", "Hello World", MyDate)
In WPF's DataGrid I can add
DataGrid1.Items.Add(New DataGridRow())
But how to fill my DataGridRow?
Private Sub AddFilesAndFolders(ByVal Base As IO.DirectoryInfo, ByRef dgv As DataGrid)
'For Each di As IO.DirectoryInfo In Base.GetDirectories
' Call AddFilesAndFolders(di, dgv)
'Next
Dim item As DataGridRow
For Each fi As IO.FileInfo In Base.GetFiles
item = New DataGridRow'<-- test 1 (row is added but empty)
Dim di As New MyFileInfo'<-- test 2 (my own class with public members, but how to add as row with declared columns?)
di.FileName = fi.FullName
di.FileDate = fi.LastAccessTime
item.Item = fi.FullName
dgv.Items.Add(di)
Next
End Sub
Hi: you should set an ItemsSource instead of adding items manually. If the columns are set up correctly then it will just 'work'!
dbv.ItemsSource = Base.GetFiles
or
dbv.ItemsSource = CreateMyFileInfos(Base.GetFiles)
If you have any more problems, please post back here.
Edit: on second inspection it looks like you may want to be doing it recursively. In which case your AddFilesAndFolders could instead be CreateFilesAndFolders, which would return a collection of FileInfo/MyFileInfo objects, merged with the collections produced by the child folders recursively; then bind the whole list returned from the first call, to the grid.
Hope that helps!
WPF is a mindset change, you need to get away from the Winforms way of thinking.
Ultimately you need to set the ItemsSource to an IEnumerable, preferably a ObservableCollection.
The quickest way to get started would be to put the ObservableCollection as a public property in your code-behind file:
public ObservableCollection<DirectoryInfo> files { get;set; }
Then in the constructor or a Load event on the Window, populate the collection with your data and then add to the Xaml declaration for your DataGrid:
ItemsSource = "{Binding Path=files}"
EDIT:
I tried this out using the DirectoryInfo class, in my code behind I added:
public ObservableCollection<DirectoryInfo> Dir = new ObservableCollection<DirectoryInfo>();
public Window1()
{
InitializeComponent();
Dir.Add(new DirectoryInfo("c:\\"));
Dir.Add(new DirectoryInfo("c:\\temp\\"));
dataGrid1.ItemsSource = Dir;
}
For some reason this was not working using the Databinding via Xaml, but I did not try very hard to get it to work.