Develop Reference

MediaElement.CurrentState retrieves System.Exception

I need to get the CurrentState from a MediaElement several times. I've created a simple function that looks like this:
private string getCurrentState(MediaElement m)
{
return m.CurrentState.ToString();
}
But everytime this function is called I get this:
An exception of type 'System.Exception' occurred in MyProject but was not handled in user code.
Additional information: The application called an interface that was marshalled for a different thread.
(Exception gfrom HRESULT: 0x8001010E (RCP_E_WRONG_THREAD))
I've been investigating about this issue and, as I've understood, it usually comes when trying to retrieve the CurrentState before the MediaOpenedevent's been fired. Actually, this not suits my case since this function is called after that. However I call the CurrentStateproperty I get the same exception and the weirdest thing of this all is that sometimes works, and sometimes not, so I definetely have got no idea of what is wrong in the code :S
Does anyone have any idea about how to fix it?

You are trying to get state from Non-ui thread. You should redesign you code to not interact with MediaElement from background thread (Task).
Or you can wrap getCurrentState method invocation into Despatcher
CoreApplication.MainView.CoreWindow.Dispatcher.RunAsync(CoreDispatcherPriority.Normal,
<lambda for your code which should run on the UI thread>);

What does the ComponentMetaData.FireError method do in an SSIS script component

I have gone through MSDN.But could not understand properly about the method mentioned below.
What does the below code do if it is included in an SSIS script destination component?
bool Error = false;
this.ComponentMetaData.FireError(0, "myScriptComponent",
"`A Transformation error occurred. Check the corresponding Text File ",
"", 0, out Error);`

The FireError method allows you to raise an error that is consistent with the built in error handling methods used elsewhere in SSIS. I.e. the above code raises an error that is picked up by the OnError event.
The parameters that follow the FireError method are described on BOL.
This can be used to provide adequate error handling (which you always should do when writing any custom code). E.g.:
Try
'Your Code Here
Catch
'Error handling here
Me.ComponentMetadata.FireError(...)
end try
In addition to .FireError, the additional .Fire... methods allow you to fire similar events that will be picked up by SSIS, e.g. .FireInformation allows you to write messages to the output window.

"Callback Error: Invalid response from server" from C# ASP.Net application

I have an ASP.Net application with a button containing the following Javascript to be invoked when it is clicked:-
function calculate() {
sectionIndex = getSelectedRadioIndex("section");
compositionIndex = getSelectedRadioIndex("composition");
CallBackOU.callback( "calculate" , sectionIndex, compositionIndex );
}
I can verify that control reaches the last line of this function by setting a breakpoint on it. But instead of invoking the method in the code-behind file...
protected void CallBackOU_Callback (object sender, ComponentArt.Web.UI.CallBackEventArgs e)
{
//blah blah
}
I get a dialogue reporting
Callback Error: Invalid response from server.
This dialogue appears three times, after which the page sits there doing nothing (forever, so far as I can make out).
I can't find any information about this. Can anyone give me any clues or pointers about how to go about diagnosing the problem?

Without seeing the signature of the calculate callback method this is only a shot in the dark but some issues i have encounter when invoking web methods from javascript are make sure the method is properly decorated [WebMethod], make sure the method is static, make sure the parameters are of the correct type and named properly (they are infact case sensitive when deserializing JSON iirc). A little more information regarding how the call is made (JSON/XML) and the signature might help. Also, you can try using fiddler to see if you get any more information regarding the error.

Exception of type 'System.Windows.Forms.AxHost+InvalidActiveXStateException' was thrown

I am getting an error in my simple project.
This is my code:
if (axZKFPEngX1.InitEngine() == 0) {
label1.Text = "Connected";
}
else {
label1.Text = "Connection Failed";
}
I already added reference composites AxInterop.ZKFPEngXControl and Interop.ZKFPEngXControl.
While debugging, I click the button, and a warning appears:
InvalidActiveXStateException was handled.
"Exception of type 'System.Windows.Forms.AxHost+InvalidActiveXStateException' was thrown"**

try to call CreateControl() from your component first.

The answer by Constantin is Fulfill your requirement but here I wanted to add one more thing with it.
If you wanted to reflected this changes via all the threads and not only by calling thread (in multiple thread scenario) then use
CreateControl();
InitWB();
SkinAllThreads();
Actually in multiple threading scenario if your skinning code is in one of the thread then may be it is not reflect change for other current thread so at that time this code is play important role in it.
Here is some Documents I mention kindly go through it for reference :
initwb() method
DirectSkin other Methods
Adding Direct Skin to Application

Can't use "apply" or "call" functions more than once

I'm using the SHDocVw DLL to open and manipulate an Internet Explorer instance from C#. I need to activate the onkeyup event of several textboxes. This is the code I use:
dynamic userNameTextBox=doc.getElementById(5749).getElementsByTagName("input")[0];
userNameTextBox.value=userName;
userNameTextBox.onkeyup.apply(userNameTextBox);
dynamic passwordTextBox=doc.getElementById(5750).getElementsByTagName("input")[0];
passwordTextBox.value=password;
passwordTextBox.onkeyup.apply(passwordTextBox);
This works for the first call to "apply", but the second call generates an error: "System.MissingMemberException: Error while invoking apply.". This problem also occurs if I use "call" instead of "apply". However, if I change one of the event invoking functions from "apply" to "call", than it works - but if I try to call this code again in the same instance of my program it throws the same exception.
In short - I can't use "apply" or "call" more then once, unless I restart my program.
This problem only occurs with Windows XP+IE8. If I try it in Windows7+IE9 I can use "apply"/"call" as many times as I want.
Is there something I could do that will allow me to use "apply"/"call" more than once, or to invoke events in any other way?

OK, I managed a workaround by invoking the event via JavaScript from the command line(AKA "Navigate"), but I still think there should be a COM(Interop?) based solution to this...