Prabu's Blog

How to get the DependencyObject under the mouse cursor?

Prabu — Mon, 17 May 2010 15:58:00 +0000

With help of VisualTreeHelper and its HitTest() methods, we can easily find the DependencyObject under the mouse cursor. Use the following code snippet to achieve this.

List<DependencyObject> hitTestList = null;

//Raised When Mouse is entered inside Panel

private void Panel_MouseEnter(object sender, MouseEventArgs e)

{

hitTestList = new List<DependencyObject>();

Point pt = e.GetPosition(sender as IInputElement);

VisualTreeHelper.HitTest(

sender as Visual, null,

CollectAllVisuals_Callback,

new PointHitTestParameters(pt));

hitTestList.Reverse();

DependencyObject elementToFind = null;

foreach (DependencyObject element in hitTestList)

{

if (element.GetType().Name.Equals(“ElementToFind”))

{

elementToFind = element;

// …

}

HitTestResultBehavior CollectAllVisuals_Callback(HitTestResult result)

{

if (result == null || result.VisualHit == null)

return HitTestResultBehavior.Stop;

hitTestList.Add(result.VisualHit);

return HitTestResultBehavior.Continue;

}

Drop me a comment if you have any queries.

How to load Bitmap image to Image object in WPF

Prabu — Fri, 14 May 2010 10:50:00 +0000

I am doing an application (which I am converting Windows forms 2.0 application into WPF application for rich look) in WPF and I am need of the load the Image from an instance of a System.Drawing.Bitmap. Initially I was struggled to do this. After a few minutes of search in goggle, I found the following solution. With help of Imaging class, we can create a BitmapSource and assign the BitmapSource value to the Image. The following code will help you to do this.

public static BitmapSource ToBitmapSource(this System.Drawing.Bitmap source)

{

BitmapSource bitmapSrc = null;

var hBitmap = source.GetHbitmap();

try

{

bitmapSrc = System.Windows.Interop.Imaging.CreateBitmapSourceFromHBitmap(

hBitmap,

IntPtr.Zero,

Int32Rect.Empty,

BitmapSizeOptions.FromEmptyOptions());

}

catch (Win32Exception)

{

bitmapSrc = null;

}

finally

{

NativeMethods.DeleteObject(hBitmap);

}

return bitmapSrc;

}

internal static class NativeMethods

{

[DllImport("gdi32.dll")]

[return: MarshalAs(UnmanagedType.Bool)]

internal static extern bool DeleteObject(IntPtr hObject);

}

Please check this link for more details.

How to close the whole application in WPF Browser based application (XBAP application)

Prabu — Tue, 04 May 2010 13:45:00 +0000

In Windows based WPF application, there is an option to close the whole application using (Application.Current.ShutDown) statement. But the same statement is not working in Web based WPF application (perhaps it will close the application. But not close the IE browser – It showing with the blank inactive tab). We have an option to close the application along with the IE window by using the following code,

private void buttonClose_Click(object sender, RoutedEventArgs e)

{

WindowInteropHelper wih = new WindowInteropHelper(Application.Current.MainWindow);

IntPtr ieHwnd = GetAncestor(wih.Handle, 2 /*GA_ROOT*/);

PostMessage(ieHwnd, 0×10/*WM_CLOSE*/, IntPtr.Zero, IntPtr.Zero);

}

[DllImport("user32", ExactSpelling = true, CharSet = CharSet.Auto)]

private static extern IntPtr GetAncestor(IntPtr hwnd, int flags);

[DllImport("user32", CharSet = CharSet.Auto)]

private static extern bool PostMessage(IntPtr hwnd, int msg, IntPtr wparam, IntPtr lparam);

How to find the visual parent or child element using VisualTreeHelper

Prabu — Wed, 28 Apr 2010 10:46:00 +0000

VisualTreeHelper is very useful class which help us to find or drill-down element from the hosted container.

The following method will help you to find the visual parent element from the container.

public static T FindVisualParent(UIElement element) where T : UIElement

{

UIElement parent = element;

while (parent != null)

{

T correctlyTyped = parent as T;

if (correctlyTyped != null)

{

return correctlyTyped;

}

parent = VisualTreeHelper.GetParent(parent) as UIElement;

}
return null;

}

The following method will help you to find the child element from the container.

public static T FindChild(DependencyObject parent)where T : DependencyObject

{

if (parent == null) return null;

T childElement = null;

int childrenCount = VisualTreeHelper.GetChildrenCount(parent);

for (int i = 0; i < childrenCount; i++)

{

var child = VisualTreeHelper.GetChild(parent, i);

T childType = child as T;

if (childType == null)

{

childElement = FindChild(child);

if (childElement != null) break;

}

else

{

childElement = (T)child;

break;

}

return childElement;

}

How to detect CTRL + ALT key combinations in WPF

Prabu — Fri, 26 Feb 2010 10:41:00 +0000

Key combinations are a fancy pair of words to describe pressing/holding multiple keyboard buttons to perform a command.

Ex:- Few of ever using key combinations are,

Ctrl + S to Save,
Ctrl + C to Copy,
Alt + F4 to close an application,
Ctrl + Alt + Del to lock our computer, etc.,

There are many such combinations, and while I provided some common ones, many applications like Visual Studio provide their own key combinations to help save you some time. Let’s add some key combinations to our little program also.

void SpecialKeyHandler(object sender, KeyEventArgs e)

{

// Ctrl + N

if ((Keyboard.Modifiers == ModifierKeys.Control) && (e.Key == Key.N))

{

MessageBox.Show(“New”);

}

// Ctrl + O

if ((Keyboard.Modifiers == ModifierKeys.Control) && (e.Key == Key.O))

{

MessageBox.Show(“Open”);

}

// Ctrl + S

if ((Keyboard.Modifiers == ModifierKeys.Control) && (e.Key == Key.S))

{

MessageBox.Show(“Save”);

}

// Ctrl + Alt + I

if ((Keyboard.Modifiers == (ModifierKeys.Alt | ModifierKeys.Control)) && (e.Key == Key.I))

{

MessageBox.Show(“Ctrl + Alt + I”);

}

The key approach doesn’t work for another reason because your commonly used Alt, Ctrl, Shift, and Windows keys can’t be accessed from the Key enum at all. Instead, those four keys can only be accessed using the ModifierKeys enum and checking whether Keyboard.Modifiers is equal to that key.

How to enable .NET Framework 3.5 SP1 Bootstrapper package in ClickOnce application.

Prabu — Wed, 30 Dec 2009 13:47:00 +0000

I have struggled with the issue which I was not able to include the .NET Framework 3.5 SP1 bootstrapper package in my click once WPF XBAP application. Even If the .NET Framework 3.5 SP1 bootstrapper package is selected in the Prerequisite dialog box for a Setup project or in ClickOnce publishing, and also the "Download prerequisites from the same location as my application" option is selected, the following build error is shown:

The install location for prerequisites has not been set to ‘component vendor’s web site‘ and the file ‘dotNetFx35setup.exe‘ in item ‘Microsoft.Net.Framework.3.5.SP1‘ cannot be located on disk.

To resolve this issue, please do the following steps:

Update the Package Data

Open the :\Program Files\Microsoft SDKs\Windows\v6.0A\Bootstrapper\Packages\DotNetFx35SP1 folder or %ProgramFiles(x86)%\Microsoft SDKs\Windows\v6.0A\Bootstrapper\Packages\DotNetFx35SP1 on x64 operating systems.
Edit the Product.xml file in Notepad.
Paste the following into the <PackageFiles> element:
Name="TOOLS\clwireg.exe"/>
Name="TOOLS\clwireg_x64.exe"/>
Name="TOOLS\clwireg_ia64.exe"/>
Find the element for Name="dotNetFX30\XPSEPSC-x86-en-US.exe" and change the PublicKey value to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
Find the element for < PackageFile Name="dotNetFX30\XPSEPSC-amd64-en-US.exe" and change the PublicKey value to the same as in step 4 above
Save the product.xml file

Download and Extract the Core Installation Files

Navigate to the following URL: http://go.microsoft.com/fwlink?LinkID=118080
Download the dotNetFx35.exe file to your local disk.
Open a Command Prompt window and change to the directory to which you downloaded dotNetFx35.exe.
At the command prompt, type:
dotNetFx35.exe /x:
This will extract the Framework files to a folder named “WCU” in the current directory.
Copy the contents of the WCU\dotNetFramework folder and paste them in the %Program Files%\Microsoft SDKs\Windows\v6.0A\Bootstrapper\Packages\DotNetFx35SP1 folder (%ProgramFiles(x86)%\Microsoft SDKs\Windows\v6.0A\Bootstrapper\Packages\DotNetFx35SP1 on x64 operating systems).

Note: Do not copy the WCU\dotNetFramework folder itself. There should be 5 folders under the WCU folder, and each of these should now appear in the DotNetFx35SP1 folder. The folder structure should resemble the following:

ü DotNetFx35SP1 (folder)

ü dotNetFX20 (folder)

ü dotNetFX30 (folder)

ü dotNetFX35 (folder)

ü dotNetMSP (folder)

ü TOOLS (folder)

ü en (or some other localized folder)

ü dotNetFx35setup.exe (file)

6. You may now delete the files and folders you downloaded and extracted in steps 2 and 4.

Please refer the following link for more details.

http://download.microsoft.com/download/A/2/8/A2807F78-C861-4B66-9B31-9205C3F22252/VS2008SP1Readme.htm#General%20Issues

How to read all countries using C#

Prabu — Fri, 18 Dec 2009 08:04:00 +0000

We can use CultureInfo & RegionInfo class for getting all the countries information. From the CultureInfo class, we can get all the Culture information available in .Net Framework. Then we can use RegionInfo class for reading all the information about the region along with the Country name. Please use the following code snippet to achieve this.

static void Main(string[] args)

{

List<string> countriesList = new List<string>();

foreach (CultureInfo culture in CultureInfo.GetCultures(CultureTypes.AllCultures & ~CultureTypes.NeutralCultures))

{

if (!string.IsNullOrEmpty(culture.Name))

{

RegionInfo ri = new RegionInfo(culture.LCID);

if (!countriesList.Contains(ri.EnglishName))

countriesList.Add(ri.EnglishName);

}

countriesList.Sort();

foreach (string str in countriesList)

Console.WriteLine(str);

Console.ReadLine();

}

How to get all Culture information using C#

Prabu — Wed, 16 Dec 2009 10:22:00 +0000

The CultureInfo class will provide us all Culture information available in .Net Framework. You can use CultureInfo.GetCultures static method for getting all the culture information. To get associated specific culture, please use static method CultureInfo.CreateSpecificCulture.

The following example will show you how to get all culture information.

static void Main(string[] args)

{
// Get culture names
List<string> list = new List<string>();

foreach (CultureInfo ci in CultureInfo.GetCultures(CultureTypes.AllCultures))

     {
          string specName = “(none)”;
          try { specName = CultureInfo.CreateSpecificCulture(ci.Name).Name;}

catch(Exception) { }

list.Add(string.Format(“{0,-12}{1,-12}{2}”, ci.Name, specName, ci.EnglishName));
}

list.Sort();

Console.WriteLine(“CULTURE SPEC.CULTURE ENGLISH NAME”);
Console.WriteLine(“—————————————————-”);

foreach (string str in list)
Console.WriteLine(str);

Console.ReadLine();
}

How to load the WPF controls dynamically at Runtime

Prabu — Tue, 03 Nov 2009 08:08:00 +0000

In order to load the WPF controls dynamically at Runtime, please do the following steps.

1. Create a dummy XAML content file (Dynamic_Content.xaml) with Controls details.

StackPanel>

2. Select the file (Dynamic_Content.xaml) in Solution Explorer and go to the properties.

3. Set “Build Action” as “Content” and “Copy to Output Directory” as “Copy always”.

4. Then you can use XamlReader class for reading the XAML content which we have the controls.

5. Please use the following code to read and load controls from XAML content file.

private void tab_TabItemAdded(object sender, TabItemEventArgs e)

{

FileStream stream = new FileStream(@”Dynamic_Content.xaml”, FileMode.Open, FileAccess.Read);

StackPanel panel = XamlReader.Load(stream) as StackPanel;

e.TabItem.Content = panel;

e.TabItem.Header = string.Format(“Tab Item – {0}”, tab.Items.Count);

stream.Close();

Button buttonStart = panel.Children[0] as Button;

buttonStart.Click += new RoutedEventHandler buttonStart_Click);

}

void buttonStart_Click(object sender, RoutedEventArgs e)

{

MessageBox.Show(“Start button invloked”);

}

How to push certificate to "Trusted root certificate authorities" using Installer

Prabu — Fri, 30 Oct 2009 09:37:00 +0000

In order to run your Full Trust enabled WPF XBAP application, you have to use “Self signed certificate authority file” for running and deploying XBAP application. The certificate should pushed it into “Trusted Publisher” and “Authority Root” certificate storages. You can use X509Certificate2 and X509Store classes in your installer assembly for pushing the certificate to certificate storage. Please use the following code snippet.

string certPath = string.Format(@”{0}\Aaa.cer”, Environment.GetFolderPath(Environment.SpecialFolder.System));

X509Certificate2 certificate = new X509Certificate2(certPath);
X509Store trustedPublisherStore = new X509Store(StoreName.TrustedPublisher, StoreLocation.LocalMachine);
X509Store trustedAuthorityRootStore = new X509Store(StoreName.AuthRoot, StoreLocation.LocalMachine);

try
{
trustedPublisherStore.Add(certificate);

trustedPublisherStore.Open(OpenFlags.ReadWrite);

trustedPublisherStore.Add(certificate);

trustedAuthorityRootStore.Open(OpenFlags.ReadWrite);

trustedAuthorityRootStore.Add(certificate);
}
catch (Exception ex)
{

MessageBox.Show(ex.Message + “\n\n” + ex.StackTrace);
}

finally
{

trustedPublisherStore.Close();

trustedAuthorityRootStore.Close();
}

For more information about Signing & Deploying CAB Based ClickOnce Code.

Please refer the following link to know more about “WPF – XBAP as Full Trust Application”

http://blogs.microsoft.co.il/blogs/maxim/archive/2008/03/05/wpf-xbap-as-full-trust-application.aspx