WebClient.OpenReadTaskAsync Method
Definition
Important
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Opens a readable stream containing the specified resource as an asynchronous operation using a task object. These methods do not block the calling thread.
Overloads
OpenReadTaskAsync(String) |
Opens a readable stream containing the specified resource as an asynchronous operation using a task object. |
OpenReadTaskAsync(Uri) |
Opens a readable stream containing the specified resource as an asynchronous operation using a task object. |
OpenReadTaskAsync(String)
- Source:
- WebClient.cs
- Source:
- WebClient.cs
- Source:
- WebClient.cs
Opens a readable stream containing the specified resource as an asynchronous operation using a task object.
public:
System::Threading::Tasks::Task<System::IO::Stream ^> ^ OpenReadTaskAsync(System::String ^ address);
public System.Threading.Tasks.Task<System.IO.Stream> OpenReadTaskAsync (string address);
[System.Runtime.InteropServices.ComVisible(false)]
public System.Threading.Tasks.Task<System.IO.Stream> OpenReadTaskAsync (string address);
member this.OpenReadTaskAsync : string -> System.Threading.Tasks.Task<System.IO.Stream>
[<System.Runtime.InteropServices.ComVisible(false)>]
member this.OpenReadTaskAsync : string -> System.Threading.Tasks.Task<System.IO.Stream>
Public Function OpenReadTaskAsync (address As String) As Task(Of Stream)
Parameters
- address
- String
The URI of the resource to retrieve.
Returns
The task object representing the asynchronous operation. The Result property on the task object returns a Stream used to read data from a resource.
- Attributes
Exceptions
The address
parameter is null
.
The URI formed by combining BaseAddress and address is invalid.
-or-
An error occurred while downloading the resource.
-or-
An error occurred while opening the stream.
Remarks
Caution
WebRequest
, HttpWebRequest
, ServicePoint
, and WebClient
are obsolete, and you shouldn't use them for new development. Use HttpClient instead.
This operation will not block. The returned Task<TResult> object will complete after the a readable stream to the data resource has been opened. This method does not block the calling thread while the stream is opening.
This method retrieves a Stream instance used to access the resource specified by the address
parameter. The stream is obtained using thread resources that are automatically allocated from the thread pool.
Note
You must call Stream.Close when you are finished with the Stream to avoid running out of system resources.
In .NET Framework and .NET Core 1.0, you can cancel asynchronous operations that have not completed by calling the CancelAsync method.
If the BaseAddress property is not an empty string ("") and address
does not specify an absolute URI, address
must be a relative URI that is combined with BaseAddress to form the absolute URI of the requested resource. If the QueryString property is not null
, it is appended to address
.
This method uses the RETR command to download an FTP resource. For an HTTP resource, the GET method is used.
Note
This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in .NET Framework.
See also
Applies to
OpenReadTaskAsync(Uri)
- Source:
- WebClient.cs
- Source:
- WebClient.cs
- Source:
- WebClient.cs
Opens a readable stream containing the specified resource as an asynchronous operation using a task object.
public:
System::Threading::Tasks::Task<System::IO::Stream ^> ^ OpenReadTaskAsync(Uri ^ address);
public System.Threading.Tasks.Task<System.IO.Stream> OpenReadTaskAsync (Uri address);
[System.Runtime.InteropServices.ComVisible(false)]
public System.Threading.Tasks.Task<System.IO.Stream> OpenReadTaskAsync (Uri address);
member this.OpenReadTaskAsync : Uri -> System.Threading.Tasks.Task<System.IO.Stream>
[<System.Runtime.InteropServices.ComVisible(false)>]
member this.OpenReadTaskAsync : Uri -> System.Threading.Tasks.Task<System.IO.Stream>
Public Function OpenReadTaskAsync (address As Uri) As Task(Of Stream)
Parameters
- address
- Uri
The URI of the resource to retrieve.
Returns
The task object representing the asynchronous operation. The Result property on the task object returns a Stream used to read data from a resource.
- Attributes
Exceptions
The address
parameter is null
.
The URI formed by combining BaseAddress and address is invalid.
-or-
An error occurred while downloading the resource.
-or-
An error occurred while opening the stream.
Remarks
Caution
WebRequest
, HttpWebRequest
, ServicePoint
, and WebClient
are obsolete, and you shouldn't use them for new development. Use HttpClient instead.
This operation will not block. The returned Task<TResult> object will complete after the a readable stream to the data resource has been opened. This method does not block the calling thread while the stream is opening.
This method retrieves a Stream instance used to access the resource specified by the address
parameter. The stream is obtained using thread resources that are automatically allocated from the thread pool.
Note
You must call Stream.Close when you are finished with the Stream to avoid running out of system resources.
In .NET Framework and .NET Core 1.0, you can cancel asynchronous operations that have not completed by calling the CancelAsync method.
If the BaseAddress property is not an empty string ("") and address
does not specify an absolute URI, address
must be a relative URI that is combined with BaseAddress to form the absolute URI of the requested resource. If the QueryString property is not null
, it is appended to address
.
This method uses the RETR command to download an FTP resource. For an HTTP resource, the GET method is used.
Note
This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in .NET Framework.