StreamReader.ReadLineAsync Method
Definition
Reads a line of characters asynchronously from the current stream and returns the data as a string.
public:
override System::Threading::Tasks::Task<System::String ^> ^ ReadLineAsync();
[System.Runtime.InteropServices.ComVisible(false)]
public override System.Threading.Tasks.Task<string> ReadLineAsync ();
override this.ReadLineAsync : unit -> System.Threading.Tasks.Task<string>
Public Overrides Function ReadLineAsync () As Task(Of String)
Returns
A task that represents the asynchronous read operation. The value of the TResult
parameter contains the next line from the stream, or is null
if all the characters have been read.
- Attributes
Exceptions
The number of characters in the next line is larger than MaxValue.
The stream has been disposed.
The reader is currently in use by a previous read operation.
Examples
The following example shows how to read the first line of a file by using the ReadLineAsync() method.
using System;
using System.IO;
namespace ConsoleApplication
{
class Program
{
static async Task Main()
{
await ReadCharacters();
}
static async Task ReadCharacters()
{
String result;
using (StreamReader reader = File.OpenText("existingfile.txt"))
{
Console.WriteLine("Opened file.");
result = await reader.ReadLineAsync();
Console.WriteLine("First line contains: " + result);
}
}
}
}
Imports System.IO
Module Module1
Sub Main()
ReadCharacters()
End Sub
Async Sub ReadCharacters()
Dim result As String
Using reader As StreamReader = File.OpenText("existingfile.txt")
Console.WriteLine("Opened file.")
result = Await reader.ReadLineAsync()
Console.WriteLine("First line contains: " + result)
End Using
End Sub
End Module