StreamWriter.WriteLineAsync Method (Char[], Int32, Int32)
Writes a subarray of characters followed by a line terminator asynchronously to the stream.
Assembly: mscorlib (in mscorlib.dll)
[ComVisibleAttribute(false)] [HostProtectionAttribute(SecurityAction.LinkDemand, ExternalThreading = true)] public override Task WriteLineAsync( char[] buffer, int index, int count )
Parameters
- buffer
-
Type:
System.Char[]
The character array to write data from.
- index
-
Type:
System.Int32
The character position in the buffer at which to start reading data.
- count
-
Type:
System.Int32
The maximum number of characters to write.
Return Value
Type: System.Threading.Tasks.TaskA task that represents the asynchronous write operation.
| Exception | Condition |
|---|---|
| ArgumentNullException | buffer is null. |
| ArgumentException | The index plus count is greater than the buffer length. |
| ArgumentOutOfRangeException | index or count is negative. |
| ObjectDisposedException | The stream writer is disposed. |
| InvalidOperationException | The stream writer is currently in use by a previous write operation. |
The line terminator is defined by the TextWriter.NewLine property.
The following example shows how to write characters to two separate lines in a text file by using the WriteLineAsync(Char[], Int32, Int32) method. The first line contains the first 11 characters from the string (the letters "First line" followed by a space). The second line contains the remaining characters from the string (the letters "and second line").
using System; using System.Text; using System.IO; namespace ConsoleApplication { class Program { static void Main(string[] args) { WriteCharacters(); } static async void WriteCharacters() { UnicodeEncoding ue = new UnicodeEncoding(); char[] charsToAdd = ue.GetChars(ue.GetBytes("First line and second line")); using (StreamWriter writer = File.CreateText("newfile.txt")) { await writer.WriteLineAsync(charsToAdd, 0, 11); await writer.WriteLineAsync(charsToAdd, 11, charsToAdd.Length - 11); } } } }
Available since 8
.NET Framework
Available since 4.5
Portable Class Library
Supported in: portable .NET platforms
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1