StringBuilder.Append Method (String, Int32, Int32)
Appends a copy of a specified substring to this instance.
Assembly: mscorlib (in mscorlib.dll)
- Type: System.String
The string that contains the substring to append.
- Type: System.Int32
The starting position of the substring within value.
- Type: System.Int32
The number of characters in value to append.
Return ValueType: System.Text.StringBuilder
A reference to this instance after the append operation has completed.
value is a null reference (Nothing in Visual Basic), and startIndex and count are not zero.
count less than zero.
startIndex less than zero.
startIndex + count is greater than the length of value.
Enlarging the value of this instance would exceed MaxCapacity.
This method appends the specified range of characters in value to the current instance. If value is a null reference (Nothing in Visual Basic) and startIndex and count are both zero, no changes are made.
The method modifies the existing instance of this class; it does not return a new class instance. Because of this, you can call a method or property on the existing reference and you do not have to assign the return value to a StringBuilder object, as the following example illustrates.
The capacity of this instance is adjusted as needed.Notes to Callers
In the .NET Framework 4 and the .NET Framework 4.5, when you instantiate the StringBuilder object by calling the StringBuilder(Int32, Int32) constructor, both the length and the capacity of the StringBuilder instance can grow beyond the value of its MaxCapacity property. This can occur particularly when you call the Append and AppendFormat methods to append small strings.
.NET FrameworkSupported in: 4.5.2, 4.5.1, 4.5, 4, 3.5, 3.0, 2.0, 1.1, 1.0
.NET Framework Client ProfileSupported in: 4, 3.5 SP1
Portable Class LibrarySupported in: Portable Class Library
.NET for Windows Store appsSupported in: Windows 8
.NET for Windows Phone appsSupported in: Windows Phone 8.1, Windows Phone 8, Silverlight 8.1
Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.