WPF C# Button Binding and TextBox to Button Binding - c#

I am fairly new to WPF and have two questions?
Question #1:
From my XAML snip below, by button "btnRed" word's fine with my code behind. When the button is clicked, the proper view is display. However, how does one perform the same thing "programmatically"? Hence, my next question.
Question #2:
I am not sure how to make a "textbox" and "button" work together to perform the same action. What I'm trying to do is this. (1) I would like the textbox to be linked to the "DataContext" of the button, "btnDisplayView". (2) so when I type in, say, "RedView" into the textbox and click the button, the correct view is displayed.
My long term goal is to have a database, with a couple of tables. A table for "MenuItems" and a table for "Views". Instead of using buttons, I'll use the menu control. Then once a menu item is selected, it would display the correct view.
But for now, I'm startings small and trying to keep it simple:
--------- WPF - XAML START ---------------------------
<StackPanel Grid.Column="0" Orientation="Vertical">
<TextBox x:Name="txtDisplayView" Height="23" Margin="5" TextAlignment="Center"/>
<Button x:Name="btnDisplayView" Content="Display" Margin="5" Click="btnDisplay_Click"/>
<Button x:Name="btnRed" Content="Red" Margin="5" DataContext="RedView" Click="Red_Click"/>
</StackPanel>
<StackPanel Grid.Column="1" Orientation="Vertical">
<ContentControl Margin="5" Content="{Binding}"/>
</StackPanel>
-----------WPF - XAML END -------------------------
If someone could show me how to get this to work, it would help me move my project in the right direction and would be greatly appreciated.

What you need here is:
Create a property in your DataContext that represents the selected item
Bind that property to your TextBox element
Now, you have two options. One is "WPF Friendly" and the other is more Windows Forms-ish:
Create a command (take a look at this article) that reads a parameter, which will be binded to the property you created before
On the Click event, you can read the binded property value
I personally prefer the first solution. Why? Because when you change it to a Menu, for example, your work will be only to populate the menu with your list items (the MenuItem class also has a Command property, so the implementation is the same as with a Button). You will only need to change the source!

Related

How can I instantiate complex group of controls and acces to their values? (wpf with visual studio)

I am trying to implement a list of programmatically instanced group of controls such as this one:
Example of my group
.
<Grid>
<TextBlock x:Name="TextBox_Data"/>
<TextBlock x:Name="TextBox_Time"/>
<TextBox x:Name="TextBlock_ID"/>
<ComboBox x:Name="ComboBox_Type"/>
<Button x:Name="Button_Data"/>
<Grid/>
It contains 2 TextBox, 1 TextBlock and 1 ComboBox and 1 button ( detail is pretty irrelevant tough) inside a Grid.
I would like to duplicate the Grid Parent to fill a list, and access to every values of the duplicated controls but I can not figure out how to do this.
I had in mind something equivalent to Android Studio java/xml combo but I couldn't find anything on this topic around here.
Any lead is more than welcome.
Thank you in advance for your time :)
Create a separate UserControl that contains your group of controls.
Do something similar to this:
WPF creating grid from XAML in code-behind
But, instead of code-behind, you can reference your new UserControl in a XAML.

How do I tab between text boxes on a form in C#?

I'm trying to get the functionality to tab to the next text box once the user has input their data for the previous text box. For example, once they filled in a company name I'd like to be able to hit Tab and set the focus on the next text box "Job Name". Is this done in the code or the form properties?
Here is some of my code. I'm unsure how to nest a KeyEventsArgs within these, which is how I've seen others set the focus to the next text boxes using the KeyPress function.
private void textBox1_TextChanged(object sender, EventArgs e)
{
CompanyName = textBox1.Text;
textBox1.AcceptsTab = true;
}
private void textBox2_TextChanged(object sender, EventArgs e)
{
JobName = textBox2.Text;
textBox2.AcceptsTab = true;
}
From the question you've asked and the code sample provided, there seems to be somewhat of a disconnect between your approach and the desired functionality.
As you would like the user to be able to use the Tab key in order to shift keyboard focus between elements in the window, you need only provide a TabIndex attribute on each of your TextBox controls. There is no need to use the TextChanged events to achieve this and it can be done completely in XAML for simplicity's sake.
From how I interpret your question, your next follow-on will likely be:
How do I initially give focus to a control when the application
starts?
To address this, there are a couple of alternatives available, simplest of which comes in the form of the FocusManager, which again I've illustrated usage of in XAML.
For convenience, here is a XAML-only implementation with TabIndex and FocusManager implemented:
<Window x:Class="tab_navigation.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:tab_navigation"
mc:Ignorable="d"
Title="MainWindow" ResizeMode="NoResize" SizeToContent="WidthAndHeight" FocusManager.FocusedElement="{Binding ElementName=TbxCompanyName}">
<Grid Margin="10">
<StackPanel Orientation="Vertical">
<StackPanel Orientation="Vertical" Margin="0,0,0,10">
<Label Content="Company Name:" Target="{Binding ElementName=TbxCompanyName}" />
<TextBox Name="TbxCompanyName" TabIndex="0" Width="160" HorizontalAlignment="Left"/>
</StackPanel>
<StackPanel Orientation="Vertical">
<Label Content="Job Description:" Target="{Binding ElementName=TbxJobDescription}"/>
<TextBox Name="TbxJobDescription" TabIndex="1" Width="160" HorizontalAlignment="Left"/>
</StackPanel>
</StackPanel>
</Grid>
Give me a shout if you need any further help, although I would strongly recommend checking out some of the MSDN resources first, particularly those concerning Focus
UPDATE: In response to comment regarding implementing the solution,
WPF has a different design and best practices from that of WinForms.
I would strongly make the case that you cease using Forms and instead use a Window or UserControl derived class in place of a Form in your WPF project unless there is a very, very good reason for doing so. If you continue to use a Form inside of your WPF project, you will indeed need to implement your own keyboard navigation logic inside that form, and bridge various other gaps you'll inevitably run into when trying to get a Form behave in a commonly acceptable way.
I'll instead show you how you can achieve your request using an objectively better and more suitable approach in WPF-only, using Window or UserControl elements. There is also a complete solution zip downloadable here.
WPF is by design a lot more modular than WinForms and splits the areas of concerns nicely by default, although most developers implement a design pattern ontop of this; MVVM is the current darling of WPF, and does add quite a lot of value to a project, although it is outside the scope of your question, so I shall instead address the question itself on the grounds of how to achieve the request in its most basic forms. Do please be aware though that this is not the entirely ideal solution and I would strongly recommend you learn and implement the MVVM pattern for WPF if you are not already familiar with it.
With that disclaimer out of the way, instead of using a Form in WPF, its more useful for us to make a class which derives from Window. An even more common scenario in WPF would be that you would want to have a single window whose content changes between different views, rather than say creating multiple windows, although again that is outside the scope of the question and would rely upon reading into Binding and MVVM. I'm going to be showing you a quick and easy way to get the functionality you've asked for, I'm just trying to iterate here that this is not the norm almost all of the time.
To make a working solution, do the following to your project:
Right click your project in the solution explorer (presuming you are using Visual Studio)
'Add' a 'New Item...'.
Choose the 'Window (WPF)' template and name it. I'm going to call it CustomerInformationEntry from here out.
Open the CustomerInformationEntry.xaml file that has been created for us, remove the <Grid></Grid> tags and copy/paste this excerpt from the XAML I've already provided from above in their place:
<Grid Margin="10">
<StackPanel Orientation="Vertical">
<StackPanel Orientation="Vertical" Margin="0,0,0,10">
<Label Content="Company Name:" Target="{Binding ElementName=TbxCompanyName}" />
<TextBox Name="TbxCompanyName" TabIndex="0" Width="160" HorizontalAlignment="Left"/>
</StackPanel>
<StackPanel Orientation="Vertical">
<Label Content="Job Description:" Target="{Binding ElementName=TbxJobDescription}"/>
<TextBox Name="TbxJobDescription" TabIndex="1" Width="160" HorizontalAlignment="Left"/>
</StackPanel>
</StackPanel>
</Grid>
Add FocusManager.FocusedElement="{Binding ElementName=TbxCompanyName} to the Window element in CustomerInformationEntry.xaml.
This is our view or visual representation finished with now, and all that remains is to instanciate a new CustomerInformationEntry from our other Window or UserControl, and to then display it. In this case I'm going to be putting a button onto the MainWindow.xaml, and providing it a click event which will create the instance of our new Window:
In MainWindow.xaml add <Button Name="BtnOpenCustomerInformationEntry" Content="Enter Customer Information" Click="OpenCustomerInformationEntry"/>. In my case I'll be adding the button inside my object, although you can put it wherever you like if you've already created your initial window.
In MainWindow.xaml.cs we'll add a new private method which will be used by the Click event of your new button. Adding the following code:
private void OpenCustomerInformationEntry(object sender, RoutedEventArgs e)
{
CustomerInformationEntry myWindow = new CustomerInformationEntry();
myWindow.Show();
}
That's it, you now have a button in your MainWindow.xaml which when clicked uses the OpenCustomerInformationEntry method defined in MainWindow.xaml.cs, which in turn makes an instance of your CustomerInformationEntry window and displays it.
If you would still rather stick with the Forms approach, you can do that by using WindowsFormsHost, usage of which is discussed here.
Best Regards,
JC

Getting a template element content or text from ControlTemplate

I'm working on a Windows Phone 8 C# and SQLite application. I'm really new to Windows Phone applications and usually work with PHP and JS.
There is a LongListSelector, which every item is a Button. Each Button should reference to an ID which is binded from a class of SQLite:
<phone:LongListSelector x:Name="llsRadios" ItemsSource="{Binding Radios}" ItemTemplate="{StaticResource DataTemplate1}"/>
DataTemplate1:
<DataTemplate x:Key="DataTemplate1">
<Grid>
<Button x:Name="btnFoo" Template="{StaticResource ButtonControlTemplate1}" Click="btnFoo_Click" />
<toolkit:ContextMenuService.ContextMenu>
<toolkit:ContextMenu IsZoomEnabled="True" x:Name="ContextMenu" >
<toolkit:MenuItem x:Name="btnEditFoo" Header="edit" Click="btnEditFoo_Click"/>
<toolkit:MenuItem x:Name="btnDeleteFoo" Header="delete" Click="btnDeleteFoo_Click"/>
</toolkit:ContextMenu>
</toolkit:ContextMenuService.ContextMenu>
</Grid>
</DataTemplate>
ButtonControlTemplate1:
<ControlTemplate x:Key="ButtonControlTemplate1" TargetType="Button">
<Grid>
<TextBlock x:Name="lblName" Text="Name" />
<TextBlock x:Name="lblCountry" Text="Country" />
</Grid>
</ControlTemplate>
I need to, when a user clicks in one of these buttons, on the event Click, get this ID value that represents a row on SQLite to then run a select * from table where ID = ..., for example.
In JavaScript, I would add a attribute data-id and handle the event like:
this.getAttribute('data-id');
// run an AJAX request
My first idea was to bind to Content of each button the ID, so I could run on btnFoo_click:
Button btn = sender as Button;
var ID = sender.Content;
// Do SQLite select.
But this doesn't seems to be the correct way to do it. Also, further on I have to work with the same concept on ConceptMenus (on hold, two options: Edit and Delete would show. These must do actions to the element which the user was selecting.)
Also I thought that I could access the template of the button and find a hidden element with the same idea of binding a value to its Text or Content attribute. But I couldn't find a way to select element from a template, kind of like jQuery's find: $('.parent').find('.element-i-need');
Sticking with this second idea, how could I search of elements by their names on a ControlTemplate of the clicked button/element?
For the first, do you know that you can get hold of the model via the DataContext? That's the most direct way to do it in a click handler:
Button btn = sender as Button;
var viewmodel = btn.DataContext as MyItemModel;
var ID = viewmodel.ID;
// Do SQLite select.
For the second, you can't access template elements directly from outside the control (there is GetTemplateChild, but that is a protected method). The rough equivalent to the JQuery "find" would be to trace down the visual tree, but that's pretty bad form in XAML, and doesn't always work (not everything is in the visual tree, Popups for example). You could however subclass the Button control, and expose a public property that makes use of GetTemplateChild.
Ideally though, your model logic shouldn't be interacting with the UI at all. When possible it is best to use <Button Command="{Binding SomeCommand}" ... /> where "SomeCommand" is an ICommand implementation, rather than <Button Click="CodeHandler" ... />. That can be easier said than done, though, especially in WP Silverlight without the FindAncestor binding ...

How to access child textbox inside cell on RadGridView

I'm using a telerik RadGridView which is pretty much the same thing as a normal DataGrid in WPF. In my gridview.columns I have a GridViewDataColumn which then allows me to put a celltemplate then a datatemplate and then allow me to put different controls within a grid. I have a combobox and a textbox(only one shows at a time based on visibility property). The problem I'm having is the tab system is kind of weird and doesn't work right. When I tab to a cell in the column above, my combobox nor my textbox ever gets focus. In fact the cell turns completly white. So I was wondering how (in code behind) can I detect when a user tabs in this particular cell and manually set focus to these child elements inside this cell on the selected row?
<telerik:GridViewDataColumn x:Name="MyDataColumn" Focusable="True" GotFocus="MyDataColumn_GotFocus_1" Header="Header1" Width="250">
<telerik:GridViewColumn.CellTemplate>
<DataTemplate>
<Grid>
<Textbox x:name="MyTextbox" Visibility="{Binding IsTextbox}"/>
<Combobox x:name="MyCombobox" Visibility="{Binding IsCombo}"/>
</Grid>
</DataTemplate>
</telerik:GridViewColumn.CellTemplate>
</telerik:GridViewDataColumn>
*Basically, how can I gain access to one of those child controls inside this GridViewDataColumn in code behind so that I can set focus to it? Thanks so much for any advice.
Probably the most straight forward answer to your question can be found by reading the answer to the Access items inside the DataTemplate in WPF post.
However, it may be worth reading the correct answer in this Access Elements inside a DataTemplate… How to for more than 1 DataTemplate? post also.

Control which field is displayed in the textbox part of a databound WPF ComboBox

I have a ComboBox in WPF which is databound, and has data template which controls how each of the items is displayed. I have made it so that each item is displayed with two bits of text (for the Name and Path properties) and one image (for the Icon property).
At the moment when I select an item from the ComboBox the textbox bit of the ComboBox just changes to say "TestWPF.Result" which is the name of the class which I have populated the ComboBox with.
I'm interested in one (or both) of two things:
How do I change it so that it displays the value of one of the fields there (eg. so it shows the value of the Name field rather than the name of the class)?
Is it possible get it to use the same DataTemplate there as in the list of items, so that once I have selected an item it displays in the closed ComboBox the same way as it looks in the list of items. Basically I've got a DataTemplate called ShowResults and a ComboBox which uses that template. I've also added in a separate ContentControl which I've got to show the details of the selected item in the ComboBox, but I want to get that to replace the textbox in the ComboBox.
Update:
Thanks for the first answer. I've tried using a separate ContentControl, as you've described, and it works fine. The question now is how to replace the textbox part of the ComboBox with this ContentControl. Any hints on that would be most welcome.
Also, is it possible to replace the textbox bit of the ComboBox control with a mixture of the ContentControl and a textbox, so that I can still type in the textbox to help select items from the ComboBox, but then when I close the dropdown the rest ContentControl bit will be populated with the rest of the text and the icon. Hope that makes sense - ask questions if it doesn't!
Code:
I've been asked to post my code - so here it is. I've tried to remove things that I know are definitely not relevant, but I'm not sure exactly what is relevant so when in doubt I've left things in.
<Window x:Class="TestWPF.Window1"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:custom="clr-namespace:TestWPF"
Title="Window1" Height="300" Width="843" Loaded="Window_Loaded">
<Window.Resources>
<DataTemplate x:Key="ShowResult" DataType="TestWPF.Result">
<StackPanel Margin="5" Orientation="Horizontal">
<Image Width="32" Height="32" Source="{Binding Path=Image}"/>
<StackPanel Margin="5">
<TextBlock FontWeight="Bold" Text="{Binding Path=Name}"/>
<TextBlock Text="{Binding Path=Path}"/>
</StackPanel>
</StackPanel>
</DataTemplate>
</Window.Resources>
<Grid Width="786">
<Button Height="23" HorizontalAlignment="Right" Margin="0,24,166,0" Name="btnTest" VerticalAlignment="Top" Width="75" Click="btnTest_Click">Add</Button>
<ComboBox StaysOpenOnEdit="True" DropDownClosed="comboBox1_DropDownClosed" PreviewTextInput="comboBox1_PreviewTextInput" SelectionChanged="comboBox1_SelectionChanged" ItemTemplate="{StaticResource ShowResult}" Margin="259,109,22,89" Name="comboBox1" IsEditable="True" />
<ContentControl Height="50" Margin="268,0,22,21" Name="contentControl1" VerticalAlignment="Bottom" Content="{Binding ElementName=comboBox1,Path=SelectedValue}" ContentTemplate="{StaticResource ShowResult}"/>
</Grid>
You got the binding part right - binding to the data and using a DataTemplate to display the source the way you want to.
As to your second question, a way to do it would be to use a ComboBox with IsEditable="True" as you have, and withing the TextChanged event handler check if the comboBox.Items contains the new value, if not check use Linq to seach for a match:
if (comboBox.Items.Contains(e.NewValue))
return;
var matches =
with comboBox.Items
select item
where item.BeginsWith(e.NewValue);
if (matches.Count > 0)
comboBox.SelectedItem = matches.First();
Just place the Property Binding expression to the textBox,You dont need to apply template.
Another way to get exact Data template, Place a ContentControl in the place of textBox and assign the same DataTemplate (say x:Name="robinTemplate")
<ContentControl Content="{Binding ElementName=cmbBox,Path=SelectedValue}" ContentTemplate="{StaticResource robinTemplate}"/>
For making the Selected content display in the same way :
Create a copy of the combobox control template and you will find a ContentPresenter there. Replace that with the ContentControl.. This is not the right solution though.

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