WindowsRuntimeStorageExtensions::OpenStreamForReadAsync Method (IStorageFile)
.NET Framework (current version)
Retrieves a stream for reading from a specified file.
This API is not CLS-compliant. Namespace: System.IO
Assembly: System.Runtime.WindowsRuntime (in System.Runtime.WindowsRuntime.dll)
[ExtensionAttribute] [CLSCompliantAttribute(false)] public: static Task<Stream^>^ OpenStreamForReadAsync( IStorageFile^ windowsRuntimeFile )
Parameters
- windowsRuntimeFile
- Type: IStorageFile
The Windows Runtime IStorageFile object to read from.
Return Value
Type: System.Threading.Tasks::Task<Stream>A task that represents the asynchronous read operation.
Usage Note
In Visual Basic and C#, you can call this method as an instance method on any object of type IStorageFile. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).| Exception | Condition |
|---|---|
| ArgumentNullException | windowsRuntimeFile is nullptr. |
| IOException | The file could not be opened or retrieved as a stream. |
The following example shows how to open a file as a Stream in a Windows Store app, and read its contents by using an instance of the StreamReader class.
The next example shows the XAML code that is associated with the previous example.
<Page x:Class="ExampleApplication.BlankPage" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" xmlns:local="using:ExampleApplication" xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" mc:Ignorable="d"> <StackPanel Background="{StaticResource ApplicationPageBackgroundBrush}" VerticalAlignment="Center" HorizontalAlignment="Center"> <TextBlock Text="Display lines from a file."></TextBlock> <Button Content="Load File" Click="Button_Click_1"></Button> <TextBlock Name="DisplayContentsBlock"></TextBlock> </StackPanel> </Page>
Show: