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How can i manage exceptions from Client.PostAsync<T>? [duplicate]

I was hoping somebody could enlighten me a little bit on an issue I am facing in regards to async/await exception handling with HttpClient. I have written some code to illustrate, and it is being excecuted on both a Windows Phone 8 device and the emulator:
private async void SearchButton_Click(object sender, EventArgs e)
{
try
{
HttpClient client = new HttpClient();
System.Diagnostics.Debug.WriteLine("BEGIN FAULTY REQUEST:");
string response = await client.GetStringAsync("http://www.ajshdgasjhdgajdhgasjhdgasjdhgasjdhgas.tk/");
System.Diagnostics.Debug.WriteLine("SUCCESS:");
System.Diagnostics.Debug.WriteLine(response);
}
catch (Exception exception)
{
System.Diagnostics.Debug.WriteLine("CAUGHT EXCEPTION:");
System.Diagnostics.Debug.WriteLine(exception);
}
}
Tapping the button that invokes this function, produces the following output in the debugger console, the most interesting being the ones in bold:
BEGIN FAULTY REQUEST:
An exception of type 'System.Net.WebException' occurred in System.Windows.ni.dll and wasn't handled before a managed/native boundary
An exception of type 'System.Net.WebException' occurred in System.Windows.ni.dll and wasn't handled before a managed/native boundary
A first chance exception of type 'System.Net.Http.HttpRequestException' occurred in mscorlib.ni.dll
An exception of type 'System.Net.Http.HttpRequestException' occurred in mscorlib.ni.dll and wasn't handled before a managed/native boundary
CAUGHT EXCEPTION:
(and here it prints out the HttpRequestException)
Of course I am expecting an error in this case since the URL I am calling is nonsense. What I am not understanding here, is why the debugger reports that the exceptions are not handled, when the output simultaneously reports that the exception is caught. Also, the UI side of the app becomes much less responsive while the output is being printed, indicating that something is probably amiss.
Is this not the way to handle exceptions when working with async and await? I appreciate any input! Thanks.

As you are using HttpClient, try to use response.EnsureSuccessStatusCode();
Now HttpClient will throw exception when response status is not a success code.
try
{
HttpResponseMessage response = await client.GetAsync("http://www.ajshdgasjhdgajdhgasjhdgasjdhgasjdhgas.tk/");
response.EnsureSuccessStatusCode(); // Throw if not a success code.
// ...
}
catch (HttpRequestException e)
{
// Handle exception.
}
ORIGINAL SOURCE OF THE CODE: http://www.asp.net/web-api/overview/advanced/calling-a-web-api-from-a-net-client

This is an artifact of the debugger. It's determining that an exception is "uncaught" because it's not caught yet. In this case this is expected behavior.
You are handling the exceptions correctly.

The debugger is telling you that this exception is first chance. When a debugger is attached to your process it gets notified for every exception that is thrown and then based on how the debugger has been configured it will decide what to do with it. You can go through What is first chance exception? for more details.
On a side note, catch specific exceptions only so that you understand which exceptions you are expecting and why.

Exception thrown: 'System.Runtime.InteropServices.COMException' in BackgroundTask.winmd The notification platform is unavailable

I got this exception while try to update the badge count using the following below code
BadgeUpdater badgeUpdater = BadgeUpdateManager.CreateBadgeUpdaterForApplication();
// And update the badge
badgeUpdater.Update(badge);

C# Azure Service Bus Multiple Exceptions Thrown For OnMessageAsync

i've been implementing a listener that responds to an OnMessageAsync. This works exactly as intended but in the debug feed it continually triggers these exceptions:
Exception thrown: 'System.ServiceModel.FaultException`1' in Microsoft.ServiceBus.dll
Exception thrown: 'System.ServiceModel.FaultException`1' in Microsoft.ServiceBus.dll
Exception thrown: 'System.ServiceModel.FaultException`1' in Microsoft.ServiceBus.dll
Exception thrown: 'System.ServiceModel.FaultException`1' in Microsoft.ServiceBus.dll
Exception thrown: 'System.ServiceModel.FaultException`1' in Microsoft.ServiceBus.dll
Exception thrown: 'System.TimeoutException' in Microsoft.ServiceBus.dll
This set of 6 exceptions seem to trigger every minute. Does anyone know why these trigger or what exactly is causing these exceptions?
code snippet:
OnMessageOptions options = new OnMessageOptions
{
MaxConcurrentCalls = 5,
AutoComplete = false
};
QueueClient client = QueueClient.CreateFromConnectionString(inboundConnectionString, ReceiveMode.PeekLock);
client.OnMessageAsync(async m =>
{
try
{
await ProcessMessageAsync(m);
...
}
...
}, options);
AutoRenewTimeout doesn't seem to make a difference in OnMessageOptions.

What could possibly cause COMExceptions while dragging file over the Desktop?

It doesn't crash, all the exceptions I mention here can only be seen in Output window of Visual Studio. Here is the implementation of Dragging:
WPF:
<StackPanel Orientation="Vertical"
MouseDown="DragShortcut"
x:Name="Shortcut">
<Image Source="{Binding Icon}"/>
<Label Content="{Binding ShortcutLabel}"/>
</StackPanel>
cs code:
private void DragShortcut(object sender, MouseButtonEventArgs e)
{
if (e.LeftButton != MouseButtonState.Pressed)
return;
var dataObject = new DataObject(DataFormats.FileDrop, new[] { Options.DragDropOptions.ShortcutPath });
DragDrop.DoDragDrop(Shortcut, dataObject, DragDropEffects.Copy);
}
Everything seems to work as expected, but every time I drag something over my Desktop or Explorer window I receive the following messages in the Output window of my Visual Studio:
...
A first chance exception of type 'System.Runtime.InteropServices.COMException' occurred in PresentationCore.dll
A first chance exception of type 'System.Runtime.InteropServices.COMException' occurred in PresentationCore.dll
A first chance exception of type 'System.Runtime.InteropServices.COMException' occurred in PresentationCore.dll
A first chance exception of type 'System.Runtime.InteropServices.COMException' occurred in PresentationCore.dll
A first chance exception of type 'System.NotImplementedException' occurred in PresentationCore.dll
A first chance exception of type 'System.Runtime.InteropServices.COMException' occurred in PresentationCore.dll
...
When Visual Studio is set to stop on that kind of exceptions, I can see the following Exceptions:
System.Runtime.InteropServices.COMException was unhandled
Message: An exception of type 'System.Runtime.InteropServices.COMException' occurred in PresentationCore.dll and wasn't handled before a managed/native boundary
Additional information: Invalid FORMATETC-Structure (Exception HRESULT: 0x80040064 (DV_E_FORMATETC))
and
System.NotImplementedException was unhandled
Message: An exception of type 'System.NotImplementedException' occurred in PresentationCore.dll and wasn't handled before a managed/native boundary
Additional information: The method or operation is not implemented.
It doesn't lead to crash or anything, it's just uncomfortable for me as a developer to have such a thing happening in background. Does anyone have an Idea what could it be?
EDIT:
This problem looks a lot like mine, but seems to have another cause and solution.

This is entirely normal. Whatever window of another process you drag over will make that process poke the object you drag to see if it supports a particular format or can convert the object to another format. Done with COM calls under the hood. If the answer is "yes" then you see the cursor change to indicate that you can drop.
The IDataObject interface implementation in WPF says "no" by throwing an exception. The normal way in which COM failure codes are generated in a .NET program. That exception gets converted by the CLR into a COM error code, an HRESULT, to tell the process that it isn't going to work. Note how the Exeption class has the HResult property, that's what the process sees.
The debugger dutifully displays the "first chance" exception notification if you asked for it. Right-click the Output window, "Exception Messages" option, turned on by default. Nothing actually goes wrong, the exception is caught and handled gracefully. Feature, not a bug.

I have a error in make a new MainWindow in wpf

I have a error in my wpf project. When I want make a new from MainWindow in The following code:
public App()
{
System.Windows.Forms.Application.EnableVisualStyles();
System.Windows.Forms.Application.SetCompatibleTextRenderingDefault(false);
if (MyServer.IsAdministrator())
{
if (MyServer.IsRun())
Process.GetCurrentProcess().Kill();
else
{
MainWindow ObjMain = new MainWindow();
ObjMain.Show();
}
}
else
{
new CheckRunAsAdministrator().ShowDialog();
Process.GetCurrentProcess().Kill();
}
}
I see:
An unhandled exception of type 'System.InvalidOperationException' occurred in PresentationCore.dll
Additional information: The calling thread must be STA, because many UI components require this.
But after this error I remove codes in App() and in App.xaml wrote
But I see another problem. Please see the below.
A first chance exception of type 'System.NotImplementedException'
occurred in PresentationFramework.dll
Additional information: The method or operation is not implemented.
and after that:
An unhandled exception of type
'System.Windows.Markup.XamlParseException' occurred in
PresentationFramework.dll
Additional information: The method or operation is not implemented.
what's the problem?