DownloadDataTaskAsync Method (String)
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WebClient.DownloadDataTaskAsync Method (String)

.NET Framework (current version)

Downloads the resource as a Byte array from the URI specified as an asynchronous operation using a task object.

Namespace:   System.Net
Assembly:  System (in System.dll)

[<HostProtectionAttribute(SecurityAction.LinkDemand, ExternalThreading = true)>]
member DownloadDataTaskAsync : 
        address:string -> Task<byte[]>


Type: System.String

The URI of the resource to download.

Return Value

Type: System.Threading.Tasks.Task<Byte[]>

Returns Task<'TResult>.

The task object representing the asynchronous operation. The Result property on the task object returns a Byte array containing the downloaded resource.

Exception Condition

The address parameter is null.


The URI formed by combining BaseAddress and address is invalid.


An error occurred while downloading the resource.

This operation will not block. The returned Task<'TResult> object will complete after the data resource has been downloaded.

This method retrieves the specified resource using the default method for the protocol associated with the URI scheme specified in the address parameter. The data is downloaded asynchronously using thread resources that are automatically allocated from the thread pool.

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 RETR command to download an FTP resource. For an HTTP resource, the GET method is used.


This member outputs trace information when you enable network tracing in your application. For more information, see Network Tracing in the .NET Framework.

The following code example requests data from a server and displays the data returned. It assumes that remoteUri contains a valid URI for the requested data.

.NET Framework
Available since 4.5
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