HowTo: Call C# method from class that has same name as namespace

image

In the C# compiler error case shown above, CaptionsGrid class exists in namespace ClipFlair.CaptionsGrid so in the code we have “using ClipFlair.CaptionsGrid;” at the top of the file where we want to call the “SaveAudio” static method of CaptionsGrid class.

But then we get the error “The type or namespace name ‘…’ does not exist in the namespace ‘…’ (are you missing an assembly reference?)”

The solution is to use a more full identifier, that is use “CaptionsGrid.CaptionsGrid.SaveAudio(…)” or even use the full namespace path “ClipFlair.CaptionsGrid.CaptionsGrid.SaveAudio(…)”. In the last case you wouldn’t need the “using ClipFlair.CaptionsGrid” at all.

It is better to avoid naming the parent namespace part of a class with the same name as the class, but some times one can’t find a better name I guess.

Fix: How to remove Trovigo.com, SearchProtect, restore Internet Options

Trovigo.com is an unwanted search engine hijacker that renders Internet Options of Windows / Internet Explorer inaccessible. To restore them on an older Windows XP installation, one way that I’ve found to work is to update Internet Explorer to a newer version, aka IE 8 (say via the embedded Windows Update facility or Microsoft Update website – http://update.microsoft.com)

The software is also probably related to a software (at least on the machine I was fixing) called "Search Protect", that is running a service and two other processes that one launches, that tries to stop you from killing it and from changing search engine option in the web browser. To remove that you can use Process Explorer from http://www.sysinternals.com:

  1. Right-click the SearchProtect service and select Suspend (do the same for the two other processes it uses) to freeze it (breaks into the process with the debugger).
  2. Right click the service node (that has the other two processes shown as children under it in the process tree) and select "Kill process tree".
  3. Go to %ProgramFiles% (usually C:\Program Files) using Windows Explorer address bar (or type this in Start/Run… dialog and press OK) and remove the folder "SearchProtect"
  4. Use free software like CCleaner (http://www.piriform.com) free edition (it has a tool to edit startup entries) or the really powerful Autoruns one to remove the now broken (since you deleted the software at step #3 references in various Windows settings that try to launch the SearchProtect software (Autoruns shows in yellow startup references to missing files, can right click and delete those entries).

Fix: Re-enable ClickOnce deployment at Mozilla Firefox

When you try to run a ClickOnce Windows application from Mozilla Firefox, on some machines you may see it try to save a .application (ClickOnce deployment manifest) instead of running the ClickOnce application installer/updater/launcher.

To fix that issue you can open Firefox add-ons dialog and search among available to download/install add-ons for "net framework assistant". From the results list select to install "Microsoft .NET Framework Assistant" (version 1.3.1 shown at the screenshot below).

You can try the ClickOnce installation process with ClipFlair‘s WebCapture tool.

image

Gotcha: System.IO.GetInvalidPathChars result not guaranteed

at System.IO.Path.GetInvalidPathChars one reads:

The array returned from this method is not guaranteed to contain the complete set of characters that are invalid in file and directory names

note: can also call this method from non-trusted Silverlight app – not as Intellisense tooltip wrongly says in Visual Studio 2013 with Silverlight 5.1

I just found out about this the hard way (since DotNetZip library was failing at SelectFiles to open .zip files that it had before successfully saved with item filenames containing colons). So I had to update my ReplaceInvalidFileNameChars string extension method to also replace/remove invalid characters such as the colon, wildcard characters (* and ?) and double quote.

    public static string ReplaceInvalidFileNameChars(
this string s,
string replacement = "") { return Regex.Replace(s, "[" + Regex.Escape( Path.VolumeSeparatorChar + Path.DirectorySeparatorChar + Path.AltDirectorySeparatorChar + ":" + //added to cover Windows & Mac in case code is run on UNIX "\\" + //added for future platforms "/" + //same as previous one "<" + ">" + "|" + "\b" + "" + "\t" + //based on characters not allowed on Windows new string(Path.GetInvalidPathChars()) + //seems to miss *, ? and " "*" + "?" + "\"" ) + "]", replacement, //can even use a replacement string of any length RegexOptions.IgnoreCase); //not using System.IO.Path.InvalidPathChars (deprecated insecure API) }


Useful to know:

System.IO.Path.VolumeSeparatorChar

slash ("/") on UNIX, and a backslash ("\") on the Windows and Macintosh operating systems

 

System.IO.Path.DirectorySeparatorChar

slash ("/") on UNIX, and a backslash ("\") on the Windows and Macintosh operating systems

 

System.IO.Path.AltDirectorySeparatorChar

backslash (‘\’) on UNIX, and a slash (‘/’) on Windows and Macintosh operating systems

More info on illegal characters at various operating systems can be found at:

http://support.grouplogic.com/?p=1607

HowTo: Drop files onto Silverlight controls

I was recently adding drop-files support to ClipFlair Studio, so I had to do some research on the related API that is available to Silverlight apps.

Silverlight supports a limited set of Drag-and-Drop interaction with the operating system (supposedly for security reasons, but most probably because of the classic cross-platform implementation pains).

For example it allows you to drop a collections of file objects from the operating system’s file explorer (or other similar application) onto a Silverlight drop target, but not the other way around.

Also, it doesn’t allow dropping other flavors of content, like text, images etc., only collections of file objects.

To allow dropping files onto a Silverlight control you set AllowDrop property to true and handle the Drop and optionally the DragEnter/DragOver/DragLeave events to provide visual feedback during the drop operation (mostly when over the drop target, unless you do Mouse Capturing).

<RichTextBox
  x:Name="rtb"
  …
  AllowDrop="True" 
  Drop="rtb_Drop"
  DragEnter="rtb_DragEnter"
  DragOver="rtb_DragOver"
  DragLeave="rtb_DragLeave"

  />

 

  #region DragAndDrop

    private void rtb_Drop(object sender, System.Windows.DragEventArgs e)
    {
      VisualStateManager.GoToState(this, "Normal", true);

      //the Drop event passes in an array of FileInfo objects for the list of files that were selected and drag-dropped onto the RichTextBox.
      if (e.Data == null)
        return;

     IDataObject f = e.Data as IDataObject;
      if (f != null) //checks if the dropped objects are files

      {
        object data = f.GetData(DataFormats.FileDrop); //Silverlight only supports FileDrop
        FileInfo[] files = data as FileInfo[]; //…GetData returns null if format is not supported

        e.Handled = true;

        if (files != null)

          //Walk through the list of FileInfo objects of the selected and drag-dropped files and parse the .txt and .docx files
          //and insert their content in the RichTextBox.
          foreach (FileInfo file in files)
            Load(file, false);
      }

    }

    private void rtb_DragEnter(object sender, System.Windows.DragEventArgs e)
    {
      VisualStateManager.GoToState(this, "DragOver", true);
      e.Handled = true;
    }
   
    private void rtb_DragOver(object sender, System.Windows.DragEventArgs e)
    {
      e.Handled = true;
      //NOP
    }

    private void rtb_DragLeave(object sender, System.Windows.DragEventArgs e)
    {
      VisualStateManager.GoToState(this, "Normal", true);
      e.Handled = true;
    }

    #endregion

 

For the visual feedback you can use VisualStateManager and respective VisualStates at say a Grid that wraps the drop target in the XAML layout.

<Grid x:Name="LayoutRoot">
   <VisualStateManager.VisualStateGroups>
     <VisualStateGroup x:Name="DragStates">
       <VisualStateGroup.Transitions>
         <VisualTransition GeneratedDuration="0:0:0.3">
           <VisualTransition.GeneratedEasingFunction>
             <CircleEase EasingMode="EaseIn"/>
           </VisualTransition.GeneratedEasingFunction>
         </VisualTransition>
       </VisualStateGroup.Transitions>
       <VisualState x:Name="Normal"/>
       <VisualState x:Name="DragOver">
         <Storyboard>
           <ColorAnimationUsingKeyFrames Storyboard.TargetProperty="(Control.Background).(SolidColorBrush.Color)" Storyboard.TargetName="rtb">
             <EasingColorKeyFrame KeyTime="0" Value="#FFFFF7D1"/>
           </ColorAnimationUsingKeyFrames>
         </Storyboard>
       </VisualState>
     </VisualStateGroup>
   </VisualStateManager.VisualStateGroups>

 

Note that on MacOS-X Safari doesn’t pass drop events automatically to plugins and you have to catch them via Javascript and pass them to Silverlight, plus I’ve read that in MacOS-X Firefox doesn’t support this at all.

Even worse, Microsoft’s workaround article has a typo in the Javascript (should call dragDrop instead of drop) and there is a chance it doesn’t work in latest version of Safari. For more see:

http://msdn.microsoft.com/en-us/library/ee670998%28v=vs.95%29.aspx

http://social.msdn.microsoft.com/Forums/silverlight/en-US/42a6b672-7d26-4690-be80-2149da755020/silverlight-4-detect-file-drop-event-on-mac?forum=silverlightarchieve&prof=required

http://community.rightpoint.com/blogs/viewpoint/archive/2011/03/27/silverlight-4-file-drag-and-drop-on-firefox-on-mac.aspx

http://www.telerik.com/forums/dropping-files-using-safari-on-mac (this says one can use HTML5 events and the Silverlight HTML/Javascript Bridge to notify Silverlight)

http://www.thebuzzmedia.com/html5-drag-and-drop-and-file-api-tutorial/

Gotcha: OnLostMouseCapture always called by CaptureMouse at WPF

It seems that CaptureMouse is behaving differently in WPF and Silverlight, in that in the former one it immediately calls OnLostMouseCapture at a Visual, whereas in Silverlight it doesn’t get called if the element didn’t have the mouse capture already (btw, in Silverlight that method is at a UIElement – there is no Visual ancestor as in WPF).

    #region --- Events ---

    private void OnMouseLeftButtonDown(object source, MouseButtonEventArgs e)
    {
      if (IsMoveToPointEnabled)
      {
        MoveThumbToPoint(e.GetPosition(this));
        CaptureMouse(); //must do before setting dragging=true, since WPF seems
//to be always calling OnLostMouseCapture on all
//controls, even if they didn't have the mouse capture
dragging = true; //always set, we might not make it to capture the mouse } } private void OnMouseLeftButtonUp(object source, MouseButtonEventArgs e) { ReleaseMouseCapture(); dragging = false; //always clear, in case we never had the mouse capture } protected override void OnMouseMove(MouseEventArgs e) { base.OnMouseMove(e); if (dragging && IsMoveToPointEnabled) MoveThumbToPoint(e.GetPosition(this)); } protected override void OnLostMouseCapture(MouseEventArgs e) { base.OnLostMouseCapture(e); dragging = false; //set dragging to false whatever the value of
//IsMoveToPointEnabled (may have changed while dragging)
} #endregion

 

The rest of the code of the SliderExt class that I’ve just added to ClipFlair codebase is below, where … is where the code region that was quoted above goes. This class is a descendent of Slider and implements IsMoveToPointEnabled property for Silverlight (in WPF that property exists), plus in WPF it fixes the behavior of the control so that when that property is set, it not only supports moving the slider thumb to the point on its track where mouse button was held down (instead of stepping up/down as is usually done in scrollbars), but also supports dragging from any point in the slider track which WPF’s implementation of IsMouseToPointEnabled didn’t do (it only allowed to drag from the thumb).

//Project: ClipFlair (http://ClipFlair.codeplex.com)
//Filename: SliderExt.cs
//Version: 20140313

using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Input;

namespace SliderExtLib
{
  public class SliderExt : Slider
  {

    public SliderExt()
    {

      //peek into mouse button events (even handled ones)
AddHandler(MouseLeftButtonDownEvent,
new MouseButtonEventHandler(OnMouseLeftButtonDown), true); AddHandler(MouseLeftButtonUpEvent,
new MouseButtonEventHandler(OnMouseLeftButtonUp), true); } #region --- Fields --- protected bool dragging; #endregion #region --- Properties --- public bool IsMoveToPointEnabled //WPF has this prop (hiding it), doesn't
//implement move to point if you click and drag on the track instead of thumb
{ get { return (bool)GetValue(IsMoveToPointEnabledProperty); } set { SetValue(IsMoveToPointEnabledProperty, value); } } public static readonly DependencyProperty IsMoveToPointEnabledProperty = DependencyProperty.RegisterAttached("IsMoveToPointEnabled", typeof(bool), typeof(SliderExt),
new PropertyMetadata(false)); #endregion #region --- Methods --- private void MoveThumbToPoint(Point p) { if (Orientation == Orientation.Horizontal) Value = p.X / ActualWidth * Maximum; else //if (Orientation == Orientation.Vertical) Value = p.Y / ActualHeight * Maximum; } #endregion




...



}
}

The incentive of making such a slider was for using it at the ColorPicker control I’ve just added to the ClipFlair codebase.

HowTo: Take screenshot on Windows desktop, Windows 8 and MacOS-X

copying from an e-mail I received from Skype support:

Taking a screenshot on Windows desktop

1. On your keyboard, press the Print Screen (Prt Scr) key to take a screenshot of your entire desktop. To take a screenshot of an active window, press the Alt+Print Screen (Prt Scr) key combination.

2. Save a copy of the image in Microsoft Paint. To do so, simply click Start > All Programs/Programs > Accessories > Paint.

3. Press the Ctrl+V key combination to paste your screenshot into Paint.

4. Go to the menu and click File > Save. Make sure you can remember where you save the image to, as you’ll need to find the file to attach the image in an email.

5. Enter a file name.

6. In the Save as type: drop-down menu, select JPEG.

7. Click Save.

Taking a screenshot on Windows 8

On your keyboard, press the Windows + Print Screen (Prt Scr) key combination. A screenshot of the entire screen is taken. To take a screenshot of an active window, press the Alt + Print Screen (Prt Scr) key combination. The screenshots are automatically saved in your Screenshots folder.

To find the folder:

1. In the Start screen, press the Windows key. Windows 8 switches to classic view.

2. Open the File Explorer from the task bar.

3. Under the Libraries folder on the left side, select Pictures. Your Screenshots folder is located here.

Taking a screenshot on Mac

On your keyboard, press the Command+Shift+4+Spacebar key combination and click the window you want to take a screenshot of.

To take a screenshot of your entire desktop, press the Command+Shift+3 key combination. To capture a portion of the desktop, press the Command+Shift+4 key combination. A cross-hair cursor will appear. Simply click and drag the cursor to select the area you’d like to capture. To save the screenshot, just release the mouse button.

The screenshots will be saved on your desktop in .png format.

Should you have further concerns or clarifications, please do not hesitate to contact us again.

It’s nice that Windows 8 now has a Screenshots folder under a user’s account folder, this is similar behaviour to the facility that Dropbox includes for taking screenshots directly to a Screenshots subfolder under your Dropbox folder. Wonder though why Windows key is needed to be pressed and what will happen if you just press PrintScreen on the Windows 8 home screen (Metro/Modern UI).

Also, wonder why Apple keeps on using those cryptic key combinations for doing things (sticking to MacOS legacy I guess).

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