WebClient.UploadStringAsync Method (Uri, String)
Uploads the specified string to the specified resource. This method does not block the calling thread.
Assembly: System (in System.dll)
[<HostProtectionAttribute(SecurityAction.LinkDemand, ExternalThreading = true)>] member UploadStringAsync : address:Uri * data:string -> unit
data is a null reference (Nothing in Visual Basic).
The address parameter is a null reference (Nothing in Visual Basic).
The data parameter is a null reference (Nothing in Visual Basic).
The URI formed by combining BaseAddress and address is invalid.
There was no response from the server hosting the resource.
This method sends a string to a resource. The string is sent asynchronously using thread resources that are automatically allocated from the thread pool. Before uploading the string, this method converts it to a Byte array using the encoding specified in the Encoding property. To receive notification when the string upload completes, you can add an event handler to the UploadStringCompleted event.
This method does not block the calling thread while the string is being sent. To send a string and block while waiting for the server's response, use one of the UploadString methods.
Asynchronous operations that have not completed can be canceled using the CancelAsync method.
If the BaseAddress property is not an empty string ("") and address does not contain an absolute URI, address must be a relative URI that is combined with BaseAddress to form the absolute URI of the requested data. If the QueryString property is not an empty string, it is appended to address.
This method uses the STOR command to upload an FTP resource. For an HTTP resource, the POST method is used.
This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing.
The HostProtectionAttribute attribute applied to this type or member has the following Resources property value: ExternalThreading. The HostProtectionAttribute does not affect desktop applications (which are typically started by double-clicking an icon, typing a command, or entering a URL in a browser). For more information, see the HostProtectionAttribute class or SQL Server Programming and Host Protection Attributes.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.