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Archive for the ‘C#’ Category

2 months ago we released wyBuild & wyUpdate v2.5. This release adds a free automatic updater control for C# & VB.NET apps. And because we wanted to keep things simple we left the wyUpdate.exe to do all the hard work (checking, download, installing) in the background while the AutomaticUpdater control is visible on your app’s main form.

We wanted the AutomaticUpdater to be able to control the update steps, view progress, and cancel the updating. But we also wanted to keep all the updating logic in the wyUpdate.exe. For this to be successful we needed a way for the AutomaticUpdater control to talk to wyUpdate.exe while it’s running.

The Answer: Inter-process communication (IPC)

Inter-Process communication is a fancy computer science way of saying “processes that can talk to each other”. Google Chrome uses IPC to communicate between tabs of the browser & plugins. It’s a simple way to keep parts of your program isolated from crashes.

For instance, if a tab of Google Chrome crashes only that single tab is killed. The rest of your tabs will continue to function normally.

Lots of bad ways to do IPC

Now that you know what inter-process communication is, let me tell you the worst ways to do it.

  • Shared memory: Difficult to set up & difficult to manage.
  • Shared files / registry: Very slow due to the writing & reading to/from disk. Difficult to manage.
  • SendMessage / PostMessage: Locks up the UI thread while the message is processed. Messages are limited to integer values. Can’t communicate from a non-admin process to an admin process. Assumes that your processes have a window.

Named Pipes

Inter process communication using named pipes is what Google Chrome uses and what we use for wyUpdate and the AutomaticUpdater control. Let me teach you about named pipes.

“Like Mario’s pipes?”

Exactly like Mario’s pipes. Except, instead of jumping Mario through the pipe, you push data through the pipe:

What do you put in the pipe?

You can transfer any data between your processes. So what data should your transfer? The answer is “it depends”. The rule of thumb is to keep it short, and keep it simple. Here’s what we do with the named pipe between wyUpdate and the AutomaticUpdater control sitting on your application:

  • Command codes: The AutomaticUpdater can command wyUpdate to check for updates, download the updates, extract the update, and install the update, or cancel any current progress.
  • Responses: wyUpdate can tell the AutomaticUpdater if there’s an update available, what changes there are in the update, and the progress of the current step (e.g. downloading).

With this simple setup the AutomaticUpdater control that’s on your application is completely isolated from wyUpdate.

Get the C# source

Download the named pipes C# source. It works with .NET 2.0, 3.0, 3.5 on Windows 2000 – Windows 7.

There are two files that do all the work: PipeServer.cs and PipeClient.cs. We use the PipeServer.cs file inside wyUpdate, and we use the PipeClient.cs file inside the AutomaticUpdater control.

Also included in the zip file is a simple messaging program to demonstrate communication between two separate processes:

Tell me what you think in the comments. I want to hear from you.

There are many Windows 7 controls already out there. I’ve included the best open source .NET components available. If you have other great controls, add them to the comments.

For each control I’ll list what versions of .NET it compiles for and what versions of Windows it will run on.

Windows Ribbon for Windows Forms

Arik Poznanski has a great series of posts about the ribbon control he wrote that wraps the Windows 7 API.

Download it now – full source code & examples. Also, view his series of articles (9 of them as of today).
Works with: Windows Forms (.NET 2.0, .NET 3.0, .NET 3.5)
Windows Versions: Only Windows 7

Windows API Code Pack for Microsoft .NET Framework

This is a mammoth control collection that is the work of 3 people.

Here are the major features:

  • Windows 7 Taskbar Jump Lists, Icon Overlay, Progress Bar, Tabbed Thumbnails, and Thumbnail Toolbars.
  • Windows 7 Libraries, Known Folders, non-file system containers.
  • Windows Shell Search API support, a hierarchy of Shell Namespace entities, and Drag and Drop functionality for Shell Objects.
  • Explorer Browser Control.
  • Shell property system.
  • Windows Vista and Windows 7 Common File Dialogs, including custom controls.
  • Windows Vista and Windows 7 Task Dialogs.
  • Direct3D 11.0, Direct3D 10.1/10.0, DXGI 1.0/1.1, Direct2D 1.0, DirectWrite, Windows Imaging Component (WIC) APIs. (DirectWrite and WIC have partial support)
  • Sensor Platform APIs
  • Extended Linguistic Services APIs
  • Power Management APIs
  • Application Restart and Recovery APIs
  • Network List Manager APIs
  • Command Link control and System defined Shell icons.

Download it now – full source code & examples.
Compiles with: Windows Forms (.NET 3.5) & Windows Presentation Foundation (WPF)
Windows Versions: Windows Vista & Windows 7

Windows 7 Progress Bar

Windows 7 Progress Bar is an open source progress bar component that allows you to add a progress bar to your program’s taskbar button. In addition, you can control the different states of the progress bar (normal, error, and paused) for Vista & Windows 7.

Download it now – full source code & examples.
Compiles with: Windows Forms (.NET 2.0, .NET 3.0, .NET 3.5)
Windows Versions: Windows 98, Windows 2000, Windows XP, Windows Vista, Windows 7

VistaMenu

VistaMenu is a menu component that allows you to add Windows 7 and Windows Vista-style menus with icons to your program. It’s written in C# and works with all .NET languages.

Download it now – full source code & examples.
Compiles with: Windows Forms (.NET 2.0, .NET 3.0, .NET 3.5)
Windows Versions: Windows 98, Windows 2000, Windows XP, Windows Vista, Windows 7

SplitButton

SplitButton is a button control with a region that shows a context menu when clicked. It’s written in C# and works with all .NET languages.

Download it now – full source code & examples.
Compiles with: Windows Forms (.NET 2.0, .NET 3.0, .NET 3.5)
Windows Versions: Windows 98, Windows 2000, Windows XP, Windows Vista, Windows 7

LinkLabel2

LinkLabel2 is a fixed version of the Windows.Forms LinkLabel control. It features the correct system “hand” cursor, and correct font rendering.

Download it now – full source code & examples.
Compiles with: Windows Forms (.NET 2.0, .NET 3.0, .NET 3.5)
Windows Versions: Windows 98, Windows 2000, Windows XP, Windows Vista, Windows 7

7 Days of Windows 7

Join me tomorrow when I talk about Finishing touches: Make your .NET app shine with professionalism. See the full list of articles in the series.

One of the great things about Vista and Windows 7 is the user isolation. Even admin users need to “elevate” their account to make system changes. Take this Date and Time dialog from Windows 7 as an example:

Every user can view the Date and time, but only administrators can change it.

Adding this ability to your .NET application

Although this series of articles is called “7 days of Windows 7” this particular article is applicable to Windows 2000 – Windows 7.

Step 1. Do we have permission?

The first step is to check if we can write to system registry or system files & folders. There are many ways to do this, but the easiest method is a simple Windows API call:

// check if user is an admin for Windows 2000 and above
[DllImport("shell32.dll", EntryPoint = "#680", CharSet = CharSet.Unicode)]
public static extern bool IsUserAnAdmin();

This will return false if you’re a limited user on Windows 2000 – Windows 7, and will also return false if you are an admin but aren’t elevated on Windows Vista and Windows 7.

In other words, it will return false if you don’t have permission to access system files & registry. And ‘ IsUserAnAdmin” returns true if you do have permission.

Step 2. Notifying the user that elevation will happen: UAC Shield Icon

To set the shield icon to one of your buttons you have to do a few things. First, set the FlatStyle of your button to “System”:

Next, you need to define a couple of functions:

public static bool AtLeastVista()
{
    return (Environment.OSVersion.Platform == PlatformID.Win32NT && Environment.OSVersion.Version.Major >= 6);
}

[DllImport("user32.dll", CharSet = CharSet.Unicode)]
public static extern IntPtr SendMessage(HandleRef hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);

public static void SetButtonShield(Button btn, bool showShield)
{
    //Note: make sure the button FlatStyle = FlatStyle.System
    // BCM_SETSHIELD = 0x0000160C
    SendMessage(new HandleRef(btn, btn.Handle), 0x160C, IntPtr.Zero, showShield ? new IntPtr(1) : IntPtr.Zero);
}

Now, simply use this snippet in your code:

…
// UAC Shield on next button for Windows Vista+
if (AtLeastVista())
    SetButtonShield(btnName, true);
…

Step 3. Re-launching process with administrator privileges

All we have to do now is show the elevation dialog and elevate the current program. You might want to specify some arguments, but the barebones of it is as follows:

ProcessStartInfo psi = new ProcessStartInfo
                           {
                               Arguments = "-justelevated",
                               ErrorDialog = true,

                               // Handle is the handle for your form
                               ErrorDialogParentHandle = Handle,
                               FileName = Application.ExecutablePath,
                               Verb = "runas"
                           };
try
{
    Process.Start(psi);
    Close();
}
catch (Exception ex)
{
    // the process couldn't be started. This happens for 1 of 3 reasons:

    // 1. The user cancelled the UAC box
    // 2. The limited user tried to elevate to an Admin that has a blank password
    // 3. The limited user tries to elevate as a Guest account
    MessageBox.Show(ex.Message);
}

Step 4. Code signing

Chances are that if you try to elevate your application you’ll get an ugly yellow elevation box:


To get the nice UAC box you’ll need to code sign your application. I won’t link to any code signing providers (because the list is huge), but you can get a code signing certificate from anywhere between $100 for 3 years to $400 or $500 for a single year. It depends on the company you use and the amount of searching you want to do.

7 Days of Windows 7

Join me tomorrow when I talk about Every possible Windows Vista and Windows 7 .NET Control You could ever want. See the full list of articles in the series.