Category Archives: Visual Studio 2015

Creating a Visual Studio debug visualizer

Note: This post was written a while back but sat in draft. I’ve published this now, but I’m not sure it’s relevant to the latest versions etc. so please bear this in mind.

A Visualizer is a feature where, if you run an app. and whilst debugging you put the mouse over a variable a little debugger popup appears. You have a drop down to display the value in the variable as XML, HTML etc.

  1. Create class lib project
  2. Add references to Microsoft.VisualStudio.DebuggerVisualizers.dll and System.Windows.Forms
using Microsoft.VisualStudio.DebuggerVisualizers;
using System.Windows.Forms;

[
    assembly: System.Diagnostics.DebuggerVisualizer(
        typeof(MyFirstVisualizer.DebuggerSide),
        typeof(VisualizerObjectSource),
        Target = typeof(System.String),
        Description = "My First Visualizer")
]
namespace MyFirstVisualizer
{
    public class DebuggerSide : DialogDebuggerVisualizer
    {
        protected override void Show(IDialogVisualizerService windowService, IVisualizerObjectProvider objectProvider)
        {
            MessageBox.Show(objectProvider.GetObject().ToString());
        }

        public static void TestShowVisualizer(object objectToVisualize)
        {
            var visualizerHost = new VisualizerDevelopmentHost(objectToVisualize, typeof(DebuggerSide));
            visualizerHost.ShowVisualizer();
        }
    }
}

TestShowVisualizer allows us to test from a console app

  1. Create console app
  2. Add reference to Microsoft.VisualStudio.DebuggerVisualizers.dll and our project reference
class TestConsole
{
   static void Main(string[] args)
   {
      var myString = "Hello, World";
      DebuggerSide.TestShowVisualizer(myString);
   }
}

To install, copy to 

{visual studio deployment folder};\Common7\Packages\Debugger\Visualizers

i.e. C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\Packages\Debugger\Visualizers

and

MyDocuments\Visual Studio 2015\Visualizers

Xamarin and Visual Studio 2015

I’ve used Xamarin Studio in the past, which is a nice enough environment, but I’ve far more experience with Visual Studio as well as having all my dev tools integrated with it (such as Resharper). Now with Microsoft’s purchase of Xamarin I’ve finally got access to Xamarin’s Visual Studio integrations which also means I can target more platforms in a single solution.

Unfortunately things didn’t “just work” out of the box.

I’m going to go through a few of the issues I found getting started with the Visual Studio integration and hopefully provide solutions and where I can I shall detail how I got everything up and running (assuming I actually do get everything up and running).

What versions am I using?

So I’m going to begin by stating what versions I’m using

  • Visual Studio Professional 2015 (version 14.0.25123.00 Update 2) on Windows 10. This version of Visual Studio includes the Xamarin integration.
  • On the Mac I’m running El Capitan and Xamarin Studio Community edition version 5.10.3 (build 51).

Creating a project

I wanted to jump straight into trying out a Cross-Platform Xamarin.Forms project, so from New Project select Cross-Platform, then Blank App (Xamarin.Forms Portable). I named the project XamarinTest1, obviously name yours whatever you like, but I may refer to this project name within this post.

Visual Studio asks me to choose the target and minimum platform versions for my Universal Windows application – I leave the defaults and press OK.

The project template supplies the following

  • Portable class library – uses for the shared/portable code
  • An Android targeted project
  • An iOS targeted project
  • A UWP/Universal Windows targeted project
  • A Windows 8.1 targeted project
  • A Windows phone 8.1 targeted project

Now my normal inclination is to press the Run button and see what happens…

Getting the Android project up and running

The Android project is selected as the Start-up project, but the first problem occurs.

A message box stating, “There were deployment errors. Continue?” appears. It’s only when I check the Output window that I see a more useful message “Please select a valid device before running the application”. It appears that Visual Studio does not know about the Android virtual devices.

Clicking on the Open Android Emulator Manager button showed I did have emulators set-up (if you hit this problem and no emulators exist, add some).

I found that if I restarted Visual Studio and reloaded the project, it then found the emulators and was able to run correctly.

Getting the iOS project up and running

Select the iOS project and right mouse click on it, then select Set as StartUp project.

To run the iOS application we need to have a Mac running with Xamarin Studio installed. Also we need to set the Sharing System Preferences on the Mac.

Invoke using Cmd-Space and search for Remote Login and then Sharing System Preferences. From here we tick the Remote Login option and set access to specific users.

Now run the iOS application in Visual Studio. If all goes well the iOS emulator will run on the Mac via the Xamarin agent and you can now see what it looks like on your chosen iOS device emulator.

Getting UWP project up and running

Select the UWP project and right mouse click on it, then select Set as StartUp project.

If you now run the UWP application you might get a message box with the following error message: “The project ‘XamarinTest1’ needs to be deployed before it can be started.” etc.

As the message box goes onto say, select the configuration manager and locate the UWP project, check the Build and Deploy options.

If all goes well the application should now run correctly.

Getting Windows 8.1 project up and running

Select the Windows 8.1 project and right mouse click on it, then select Set as StartUp project.

This project should simply work, without any changes required.

Getting Windows Phone 8.1 project up and running

Select the Windows Phone 8.1 project and right mouse click on it, then select Set as StartUp project.

You will need the Windows 8.1 Phone emulator running on your machine (if using Windows 10) and this in turn requires the Hyper V virtualization option on the computer’s BIOS turned on.

Running the application will result in you being asked to download/install the emulator if it’s not on your machine. It’s likely you’ll need to reboot upon completion and/or may be asked if your login user should be part of the Hyper V group – which it should. Once everything is installed correctly then you’ll see a Windows phone emulator appear when you run the application.

Conclusions

It’s unfortunate this stuff doesn’t “just work” immediately out of the box, but with a little tweaking/configuring you can get five different projects running against five different device types and now the world of cross platform C# awaits.

Addendum

Part way through writing this document I foolishly decided to update the Android SDK only to find it failed and left my installation in a non-working state. So here’s what I had to do to get the system working again.

  • Android SDK didn’t appear to be available as a separate download, so I had to install Android Studio and download the NDK seperately
  • Once installed I found the folders of the installations very different from my original install so I needed to option Visual Studio’s Tools | Options
  • Select Xamarin | Android Settings
  • Change the JDK, SDK and NDK paths

So it’s not without its pain points, but eventually I had each of the platform targeted projects running.

Strange white on black numbers during debug in Visual Studio 2015

When running a Universal Windows application in debug mode within Visual Studio 2015 I noticed some “strange” white numbers on a black background adorning my application window (and in the case of a desktop application displayed on the top right of the screen).

It seems these are enabled via the App.xaml.cs file, within the OnLaunched method (the code in some cases may appear in the App() constructor according to the documentation) there’s the following code

#if DEBUG
   if(System.Diagnostics.Debugger.IsAttached)
   {
      this.DebugSettings.EnableFrameRateCounter = true;
   }
#endif

See also DebugSettings.EnableFrameRateCounter property.

As stated within the above link, this causes an overlay of two sets of numbers. Those in the upper left of the screen/Window relate to the application being debugged those in the upper right apply to the overall system.

Basically the left number is the app’s UI frame rate in frames per second and the right number is the CPU usage of the app’s UI thread per frame in milliseconds.