- KOMPLETE 10 ACTION STRINGS HOW TO
- KOMPLETE 10 ACTION STRINGS INSTALL
- KOMPLETE 10 ACTION STRINGS CODE
TotalZeroBytesRead += buffer.Count(Function(b) b = 0) ' Asynchronously read from the file stream.īytesRead = await fileStream.ReadAsync(buffer, 0, buffer.Length) Using fileStream = New FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read, &H1000, True) Private Shared async Function CountBytesAsync(ByVal path As String) As Task(Of Integer) ' Asynchronously computes the number of zero bytes that the provided file Asynchronously read from the file stream.īytesRead = await fileStream.ReadAsync(buffer, 0, buffer.Length) Path, FileMode.Open, FileAccess.Read, FileShare.Read, 0x1000, true)) Static async Task CountBytesAsync(string path) Asynchronously computes the number of zero bytes that the provided file The ReadAsync method performs file read operations asynchronously.
The following example modifies the CountBytes method and uses the async and await operators ( Async and Await in Visual Basic) to asynchronously compute the total number of bytes that are zero in the provided file. When a dataflow block behaves asynchronously, the task of the dataflow block is complete only when the returned Task object finishes. To enable the dataflow block to behave asynchronously, provide a delegate of type Func to the dataflow block. This example provides a delegate of type Func to the TransformBlock object to perform the task of the dataflow block synchronously. The table also specifies whether the delegate type operates synchronously or asynchronously. The section Summary of Delegate Types in the Dataflow document summarizes the delegate types that you can provide to ActionBlock, TransformBlock, and TransformManyBlock objects. For more information about how lambda expressions work in the Task Parallel Library, see Lambda Expressions in PLINQ and TPL. The ActionBlock object uses a lambda expression because the work to be performed is specific to this task and is not likely to be useful from other code.
KOMPLETE 10 ACTION STRINGS CODE
' Wait for the ActionBlock object to print the message.Īlthough you can provide a lambda expression to a TransformBlock object, this example uses Func to enable other code to use the CountBytes method. ' Requests completion of the TransformBlock object. ' Post the path to the temporary file to the ' object when the TransformBlock finishes.Ĭ(Sub() printResult.Complete()) ' Create a continuation task that completes the ActionBlock
' CountBytes function and returns its result.ĭim countBytes = New TransformBlock(Of String, Integer)(New Func(Of String, Integer)(AddressOf DataflowExecutionBlocks.CountBytes)) ' Create a TransformBlock object that calls the Var printResult = new ActionBlock(zeroBytesRead =>Ĭonsole.WriteLine(" zero bytes.", Path.GetFileName(tempFile), zeroBytesRead)) Using (var fileStream = File.OpenWrite(tempFile))įor (int i = 0 i object that prints to the console Write random data to the temporary file. String tempFile = Path.GetTempFileName() TotalZeroBytesRead += buffer.Count(b => b = 0) Using (var fileStream = File.OpenRead(path))īytesRead = fileStream.Read(buffer, 0, buffer.Length) Computes the number of zero bytes that the provided file
KOMPLETE 10 ACTION STRINGS HOW TO
Demonstrates how to provide delegates to exectution dataflow blocks. The ActionBlock object uses a lambda expression to print to the console the number of zero bytes that are read. The TransformBlock object specifies a Func object to perform work when the blocks receive data. It uses TransformBlock to read the file and compute the number of zero bytes, and ActionBlock to print the number of zero bytes to the console. The following example uses dataflow to read a file from disk and computes the number of bytes in that file that are equal to zero.
KOMPLETE 10 ACTION STRINGS INSTALL
To install the namespace in Visual Studio, open your project, choose Manage NuGet Packages from the Project menu, and search online for the package. The TPL Dataflow Library (the namespace) is not distributed with.
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