Develop Reference

XAML Forms not recognizing local and referenced classes

I opened a VS 2012 Solution in VS 2015 and cannot get it to compile. It was originally targeting .Net 3.5 and used the WPF Toolkit, which caused some ambiguous references. I resolved that by removing the reference to the WPF Toolkit and replacing it with the package DotNetProjects.Wpf.Toolkit.
Now I have to tackle the next issue, which I suspect is not caused by the obvious but is a cascade from some other hidden gotcha from upgrading the versions.
My XAML forms are not recognizing the existence of classes within referenced namespaces. I can get them to come up on intellisense but the application won't compile and the error says something like: "The name "MainWindow" does not exist in the namespace "clr-namespace:FieldSheetPrinter".
I have defined my main form with the following:
<Window
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:FieldSheetPrinter"
mc:Ignorable="d"
xmlns:Custom="http://schemas.microsoft.com/netfx/2009/xaml/presentation"
xmlns:validationRules="clr-namespace:SWallTech.ValidationSupport;assembly=SWallTech.ValidationSupport"
xmlns:FieldSheetPrinter_Converters="clr-namespace:FieldSheetPrinter.Converters"
xmlns:Converters="clr-namespace:SWallTech.WPF.Support.Converters;assembly=SWallTech.WPF.Support"
x:Class="FieldSheetPrinter.MainWindow"
x:Name="MainWindow"
Title="CAMRA Field Sheet Printer - Stonewall Technologies, Inc."
Width="744"
Height="583"
WindowStartupLocation="CenterScreen"
Icon="CamraPrint.ico">
I have references to the SWallTech.WPF.Support project, which is in the solution, and the compiler has no problem recognizing the classes in that project's Converters namespace. This code has no error indicator. (Red squiggles.)
<Converters:IntGreaterThanZeroToVisibilityConverter
x:Key="IntGreaterThanZeroToVisibilityConverter" />
<Converters:DatabaseConnectionImageSourceConverter
x:Key="DatabaseConnectionImageSourceConverter" />
However if I try to refer to the ViewModel I am using as the datasource, I get an error:
<local:FieldSheetPrinterViewModel
x:Key="FieldSheetPrinterViewModelDataSource"
d:IsDataSource="True" />
I also get the error that the XAML form itself is not in the namespace FieldSheetPrinter, which of course it is, as you can see from the Code-Behind.
namespace FieldSheetPrinter
{
public partial class MainWindow : Window
...
}
I have tried everything I can think of, and I am truly stumped.
Joey

As suggested above, the problem wasn't directly with the XAML, or at least not completely. The original developer had named the Window tag with the same name as the code-behind class name, and that seems to be prohibited now. That was the only issue with the XAML. Everything else had to do with overlaps in the WPF and Windows.System.Data libraries that caused IValueConverter (in the System.Windows.Data namespace) to go unrecognized. I eliminated any other references that could have conflicted, and corrected some syntax issues in the code-behind that apparently were deprecated.
Ex.
stringVariable.IsNullOrEmpty()
was used instead of
string.IsNullOrEmpty(stringVariable)
In other places some ObservableCollection objects weren't recognized as enumerable, so I had to add "ToList()" before looping through the collection.
Weird, but I didn't write this stuff!
Thanks for the suggestions.
Joey

Create an instance of a C# class from inside XAML

I have a working application that has been written in C#, and I now want to extend that application to allow the user to switch between viewing the application, and viewing a built in web browser (inside the same application window).
I also have a separate working web browser, that has also been written in C#.
I have just added the functionality to the original application to include 'tabbed' displays, where the original application will be displayed on the first tab, and a built in web browser on the second tab.
The 'tabbed' displays for the application have been created using XAML markup in Visual Studio. I now want to add an instance of the Web browser that has also been written in C# to the second tab that I have created in the XAML markup.
It would be something like:
<TabControl>
<TabItem Header="Browser">
<StackPanel>
<!-- Call/ instantiate the browser here -->
</StackPanel>
</TabItem>
</TabControl>
But I have no idea how I call/ create an instance of the browser from within the XAML markup...
The browser has been created using C#:
namespace Agent
{
public partial class Browser : Form
{
public Browser()
{
...
}
}
}
Can anyone explain to me how a create an instance of Browser inside the ` of the XAML markup?
Edit
Ok, so I have edited my XAML markup as recommended in the answer that's been suggested- I now have:
<Window ...
xmlns:Agent="clr-namespace:Agent"
...>
<Grid>
...
<TabControl>
<TabItem Header="R">
<StackPanel>
...
</StackPanel>
</TabItem>
<TabItem Header="Browser">
<Agent:Browser x:Name="Browser" />
</TabItem>
</TabControl>
</Grid>
</Window>
I have also updated my Browser.cs class, so that it is now extending UserControl, rather than Form:
public partial class Browser : UserControl{
However, I am getting a compile error on the line:
<Agent:Browser x:Name="Browser" />
which says:
The name "Browser" does not exist in the namespace "clr-namespace:Agent".
But clearly Browser does exist in Agent, as shown by the code I've included here... In fact, when typing the line <Agent:Browser x:Name="Browser />, when I typed the :, Browser was one of the options that came up in the autocomplete menu...
What am I doing wrong here? Why doesn't the compiler think that Browser exists inside Agent?

The key to instantiating any object in XAML is to make sure the namespace is declared. You can provide any XML prefix and assign it to your CLR namespace (ref) and it will act like a using statement. For example:
<TabControl xmlns:agent="clr-namespace:Agent">
<TabItem Header="Browser">
<StackPanel>
<agent:Browser/>
</StackPanel>
</TabItem>
</TabControl>
NOTE: your object has to extend UIElement (or one of its children) for it to work in a XAML tree. If your control is a WinForms control you either need to find the equivalent XAML control or wrap it in a WindowsFormsHost (ref).
WPF vs. WinForms
The purpose of this section is to help recognize which platform code is by namespace, as well as some of the trade-offs. I've used both and can say from experience that they each have good points and... not so good points.
WinForms classes live in the System.Windows.Forms namespace, and are available by referencing the System.Windows.Forms.dll assembly.
WPF classes live in the System.Windows and System.Windows.Controls namespaces, and are available by referencing a set of DLLs
WinForms rendering is immediate. That means you are working against bitmaps and you are responsible for clearing and redrawing stuff yourself (usually you can just call Invalidate()). If you do heavy image bit manipulation, WinForms is easier to work with.
WPF rendering is declarative. That means more work is offloaded to your GPU and you just tell it how to draw stuff. You can also use GPU render shaders for special effects. WPF has a nicer look out of the box, but it has a reputation for making easy things difficult but impossible things possible.
WinForms is easier to learn, but has a dated look out of the box.
WPF is built around data binding, enabling the UI to update in response to property values automatically. It's also able to be completely restyled, although that is quite an undertaking.
If you are just getting started, I'd go ahead and bite the bullet to start the heavier learning curve for WPF. It will provide a basic understanding that transfers to other platforms like Windows Store apps, etc.

Firstly you need to place that tag inside of your UserControl opening tag like so:
<UserControl x:Class="View.testControl"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:Agent="clr-namespace:Agent">
Then you can use it like this:
<TabControl>
<TabItem Header="R">
<StackPanel>
...
</StackPanel>
</TabItem>
<TabItem Header="Browser">
<Agent:Browser x:Name="Browser" />
</TabItem>
</TabControl>
EDIT
From what you told me in the comments you will need to create a Custom Control in your WPF project. To do that you need to:
Right Click your Project;
Select Add New Item;
From Installed (which is in the left column) select WPF;
From the list in the middle column select Custom Control;
Now you can create that control in your XAML with xmlns attribute.
Here is a great example from msdn on how to create custom controls

Incorrect type passed into template. Based on the x:DataType global::SMARTWms.Model.Login was expected

By followed the sample from here https://github.com/Microsoft/Windows-universal-samples/tree/master/Samples/XamlListView/cs/Samples/MasterDetailSelection, i created a master detail page named SecuritySettingsPage.
The master detail page works fine until I put it under Pivot in another page as shown below:
<PivotItem Header="Security">
<view:SecuritySettingsPage />
</PivotItem>
The above error happened whenever i browse to that particular pivot when running the program. The error would go away and pivot display data correctly if i click the "Continue" button from the Visual Studio.
I have no idea on how to resolve it. Could anyone enlighten me please?

I managed to solve the above by passing a null DataContext.
<PivotItem Header="Security">
<view:SecuritySettingsPage DataContext="{x:Null}"/>
</PivotItem>

ScrollViewer CanContentScroll Property not Found (Windows 8.1 Universal App)

I'm trying to get a ScrollView to logical scroll instead of physically. After reading up online on how to do this, most sources say to set the CanContentScroll property to False. However, when attempting to do this, it seems that ScrollViewer doesn't have this property.
Here is my XAML code:
<ScrollViewer x:Name="TestScroll" CanContentScroll="True" HorizontalScrollBarVisibility="Disabled" HorizontalScrollMode="Disabled" Margin="66,215,1020,10" Grid.Row="1">
<StackPanel x:Name="TestPanel" Orientation="Vertical">
</StackPanel>
</ScrollViewer>
And the error(s) thrown:
Error 1 The member "CanContentScroll" is not recognized or is not accessible.
Error 2 The property 'CanContentScroll' was not found in type 'ScrollViewer'
I am developing for Windows 8.1, creating a universal app. I feel like I'm missing something like a reference or something incredibly simple because everywhere else that I have looked, it just works.
Any help would be appreciated.

Figured it out, using the VerticalSnapPointsType="Mandatory" property for ScrollViewer instead.

Windows phone 7.1 ListPicker, easy way to go full mode?

I'm trying to use the ListPicker controller with ListPickerMode="Full", to get the fullscreen pick window. However it just generate an error when i try
"A first chance exception of type 'System.Windows.Markup.XamlParseException' occurred in System.Windows.dll
Additional information: Set property Microsoft.Phone.Controls.ListPicker.ListPickerMode threw an exception. [Line: 49 Position: 57]"
Here's my code:
<toolkit:ListPicker x:Name="OutputSelector" ListPickerMode="Full"
Margin="0,542,6,0" Header="Output Type" Width="450" VerticalAlignment="Top" />
I populate my ListPicker in C# using a list to set as ItemSource if that is any help.
Another thing is that when i try to write "ListPickerMode" in xml it doest give it as an option, but when i have written the whole thing it suggest "Full" "expanded" and "Normal".
If i add 5 items to the ListPicker it automatically uses FullMode, and i have tried changing ItemCountThreshold="0" but that just generate more errors.
I'm using Windowns Phone 7.1 OS 2011 aug release.
It's probably just me that is stupid, first day with Windows Phone programing :)
UPDATE!
Well it looks like ItemCountThreshold & ListPickerMode was remove for 7.1 or something, atleast in XAML part, not the C# part, where they are read only.
Solution for my problem!
<toolkit:ListPicker x:Name="OutputSelector" ExpansionMode="FullScreenOnly"
Margin="0,542,6,0" Header="Output Type" Width="450" VerticalAlignment="Top" />
The ExpansionMode will make the Listpicker appear in fullscreen or expanded.

As stated in the issue tracker of the silverlight toolkit [1], ItemCountThreshold should not be set (and cannot be set using simple xaml).
However, there are two workarounds for this issue. If you you don't mind to use codebehind, set the property via SetValue:
//e.g., in the constructor, just after InitializeComponent();
ListPicker.SetValue(Microsoft.Phone.Controls.ListPicker.ItemCountThresholdProperty, 0);
To set the value in xaml, you can use a binding:
<toolkit:ListPicker ItemCountThreshold="{Binding Hugo,FallbackValue=0}">(...)
In this example, I use a bogus binding expression and set the value using FallbackValue. Of course, an actual working binding should work as well. The xaml approach was only tested on the WP8 SDK, however it should work on 7.1 as well.
Edit: Just found out that the xaml approach breaks the designer.
[1] http://silverlight.codeplex.com/workitem/9742

The solution proposed by the author (moving here for better visibility):
Well it looks like ItemCountThreshold & ListPickerMode was remove for
7.1 or something, atleast in XAML part, not the C# part, where they are read only.
Solution for my problem!
<toolkit:ListPicker x:Name="OutputSelector" ExpansionMode="FullScreenOnly"
Margin="0,542,6,0" Header="Output Type" Width="450" VerticalAlignment="Top" />
The ExpansionMode will make the Listpicker appear in fullscreen or
expanded.