Error HRESULT E_FAIL has been returned from a call to a COM component

In Silverlight 4 app; what does this error mean?:

"Error HRESULT E_FAIL has been returned from a call to a COM component."

It's a very generic error. The VS debugger doesn't point to the exact location of the error when debugging.

Silverlight 4 Data Binding with anonymous types

Does anyone know if you can use data binding with anonymous types in Silverlight 4? I know you can't in previous versions of silverlight, you can only databind to public class properties and anonymous type properties are internal.

Just wondering if anyone has tried it in silverlight 4?

Silverlight 4.0: How to convert byte[] to image?

public Image Base64ToImage(string base64String)
    {
        // Convert Base64 String to byte[]
        byte[] imageBytes = Convert.FromBase64String(base64String);
        MemoryStream ms = new MemoryStream(imageBytes, 0,
          imageBytes.Length);

        // Convert byte[] to Image
        ms.Write(imageBytes, 0, imageBytes.Length);
        System.Drawing.Image image = System.Drawing.Image.FromStream(ms, true);
        return image;
    }

I want to convert byte[] to image, however System.Drawing.Image is not supported in Silverlight. Any alternative?

Difference between ItemsSource and DataContext as pertains to ListBox

I am not quite grokking the difference between ItemsSource and DataContext. Can someone explain it and back it up with examples? When would I use one or the other.

I am reading the docs and it says that I can bind using DataContext, but I throw an ObservableCollection at it and nothing shows up in the list. If I throw the same collection at the ItemsSource, it works fine.

Streaming a webcam from Silverlight 4 (Beta)

The new webcam stuff in Silverlight 4 is darned cool. By exposing it as a brush, it allows scenarios that are way beyond anything that Flash has.

At the same time, accessing the webcam locally seems like it's only half the story. Nobody buys a webcam so they can take pictures of themselves and make funny faces out of them. They buy a webcam because they want other people to see the resulting video stream, i.e., they want to stream that video out to the Internet, a lay Skype or any of the dozens of other video chat sites/applications. And so far, I haven't figured out how to do that with

It turns out that it's pretty simple to get a hold of the raw (Format32bppArgb formatted) bytestream, as demonstrated here.

But unless we want to transmit that raw bytestream to a server (which would chew up way too much bandwidth), we need to encode that in some fashion. And that's more complicated. MS has implemented several codecs in Silverlight, but so far as I can tell, they're all focused on decoding a video stream, not encoding it in the first place. And that's apart from the fact that I can't figure out how to get direct access to, say, the H.264 codec in the first place.

There are a ton of open-source codecs (for instance, in the ffmpeg project here), but they're all written in C, and they don't look easy to port to C#. Unless translating 10000+ lines of code that look like this is your idea of fun :-)

const int b_xy= h->mb2b_xy[left_xy[i]] + 3;
const int b8_xy= h->mb2b8_xy[left_xy[i]] + 1;
*(uint32_t*)h->mv_cache[list][cache_idx ]= *(uint32_t*)s->current_picture.motion_val[list][b_xy + h->b_stride*left_block[0+i*2]];
*(uint32_t*)h->mv_cache[list][cache_idx+8]= *(uint32_t*)s->current_picture.motion_val[list][b_xy + h->b_stride*left_block[1+i*2]];
h->ref_cache[list][cache_idx ]= s->current_picture.ref_index[list][b8_xy + h->b8_stride*(left_block[0+i*2]>>1)];
h->ref_cache[list][cache_idx+8]= s->current_picture.ref_index[list][b8_xy + h->b8_stride*(left_block[1+i*2]>>1)];

The mooncodecs folder within the Mono project (here) has several audio codecs in C# (ADPCM and Ogg Vorbis), and one video codec (Dirac), but they all seem to implement just the decode portion of their respective formats, as do the java implementations from which they were ported.

I found a C# codec for Ogg Theora (csTheora, http://www.wreckedgames.com/forum/index.php?topic=1053.0), but again, it's decode only, as is the jheora codec on which it's based.

Of course, it would presumably be easier to port a codec from Java than from C or C++, but the only java video codecs that I found were decode-only (such as jheora, or jirac).

So I'm kinda back at square one. It looks like our options for hooking up a webcam (or microphone) through Silverlight to the Internet are:

(1) Wait for Microsoft to provide some guidance on this;

(2) Spend the brain cycles porting one of the C or C++ codecs over to Silverlight-compatible C#;

(3) Send the raw, uncompressed bytestream up to a server (or perhaps compressed slightly with something like zlib), and then encode it server-side; or

(4) Wait for someone smarter than me to figure this out and provide a solution.

Does anybody else have any better guidance? Have I missed something that's just blindingly obvious to everyone else? (For instance, does Silverlight 4 somewhere have some classes I've missed that take care of this?)

Binding to Converter Parameter

Is it possible to bind to a ConverterParameter in Silverlight 4.0?

For instance I would like to do something like this and bind the ConverterParameter to an object in a ViewModel for instance.

If this is not possible are there any other options?

<RadioButton
  Content="{Binding Path=Mode}"
  IsChecked="{Binding
    Converter={StaticResource ParameterModeToBoolConverter},
    ConverterParameter={Binding Path=DataContext.SelectedMode,ElementName=root}}"
/>

Silverlight 4.0 PDF Viewer [closed]

Any free control to view PDF for Silverlight?

or how to view pdf in silverlight from memory stream?

4 points and Ellipse

I have 4 points.. i can draw a polygon usign this code

var p = new Polygon();
p.Points.Add(new Point(0, 0));
p.Points.Add(new Point(70, 0));
p.Points.Add(new Point(90, 100));
p.Points.Add(new Point(0, 80));

How i can draw an 'ellipse' that will fit in this polygon, using Silverlight?

Question is still unanswared!!!

How to zoom in and zoom out Images in WP7?

I have made an application which displays Images .Now I want to implement zoom in and zoom out feature(by using two fingertip's) as in native windows phone photo viewer application.Any idea on how to proceed .

Thanks in Advance.

how to bind width of child element to width of parent element in silverlight

I have a grid whose width is "1*". So the actual width decided at runtime I think. Within that grid I have another grid whose width I want to set to the runtime width of parent grid. How Can I do that in xaml through binding.

Visual Studio Debugging with Silverlight 4 and Firefox

When trying to debug a Silverlight 4 application in Visual Studio 2010 with Firefox as my browser, I am unable to hit any breakpoints. I get the message "breakpoint will not currently be hit".

What is the replacement for DataTrigger in Silverlight

This is my scenario.

I have 2 Properties. Type and State.

Type is an Enum with 3 values eg, ball, car, arrow. State is an int which would accept 3 state values eg., -1, 0, 1. Also, I have 9 images for each state values.

Like, if I select type as ball and value as -1, I want to display a Red color ball. If I select type as arrow and value as 1, I want to display a up arrow. etc.,

I'm able to do this in WPF. I created 3 DataTemplates with an empty Image. Then, I use DataTrigger to check and update the particular image for the selected StateValue.

But, in silverlight how can I do this. I know, I have to do it in VSM. But, I would like to know some more details regarding this (or) any alternatives available.

How to wrap text in Silverlight DataGridTextColumn

I am trying to create a simple DataGrid in Silverlight 4 Beta but cannot seem to figure out how to get my Note column to wordwrap.

The table represents notes made on an order, so they will be of variable length. i want the 'Note' cell to expand vertically to fit the contents.

I've found numerous similar questions but no answer. Is there something new in Silverlight 4 that will address this?

    <data:DataGrid AutoGenerateColumns="False" Name="dataGrid1" IsReadOnly="True">
        <data:DataGrid.Columns>
            <data:DataGridTextColumn Header="Date" Binding="{Binding Date}" />
            <data:DataGridTextColumn Header="User" Binding="{Binding User}" />
            <data:DataGridTextColumn Header="Note" Binding="{Binding Note}"  />
        </data:DataGrid.Columns>
    </data:DataGrid>

Programmatically measure text string in pixels for Silverlight

In WPF there is the FormattedText in the System.Windows.Media namespace MSDN FormattedText that I can use like so:

private static Size GetTextSize(string txt, string font, int size, bool isBold)
{
   Typeface tf = new Typeface(new System.Windows.Media.FontFamily(font),
                             FontStyles.Normal,
                             (isBold) ? FontWeights.Bold : FontWeights.Normal,
                             FontStretches.Normal);
   FormattedText ft = new FormattedText(txt, new CultureInfo("en-us"), System.Windows.FlowDirection.LeftToRight, tf, (double)size, System.Windows.Media.Brushes.Black, null, TextFormattingMode.Display);
   return new Size { Width = ft.WidthIncludingTrailingWhitespace, Height = ft.Height };
}

Is there a good approach in Silverlight to getting the width in pixels (at the moment height isn't important) besides making a call to the server?

Silverlight 4 Equivalent to WPF "x:static"

I'm working on a project that is based on an old project someone started and didn't finish. I was trying to use as much of their code as I could, so in doing so I ran into some tweaking issues.

Namely, when I put some of the old xaml in the new project there were some errors that were thrown regarding the "x:static" property and "Dynamic property."

here are the error messages themselves:

Error 1: The type 'DynamicResource' was not found. Verify that you are not missing an assembly reference and that all referenced assemblies have been built.

Error 2: The type 'x:Static' was not found. Verify that you are not missing an assembly reference and that all referenced assemblies have been built.

Some notable points that I think is causing the errors: the old project was programmed in VS2008, WPF, v3.5 .Net framework; whereas I am programming in VS2010, Silverlight 4, .Net framework v4.0.

I realize there are differences from WPF to Silverlight as far as xaml goes and there are plenty of differences from the different .Net framework versions and editions of Visual Studio. But I just can't seem to find a fix for this anywhere so I didn't know if there was just a library I was missing or just something I'm simply overlooking or what.

I can recreate this if need be, but like I said, I'd rather use as much of the old code as I can as long as the tweaking doesn't cause more trouble than what it's worth.