Articolo
11/18/2011

MemoryStream.SetLength Method

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Sets the length of the current stream to the specified value.

Namespace: System.IO
Assembly: mscorlib (in mscorlib.dll)

Syntax

'Declaration
Public Overrides Sub SetLength ( _
    value As Long _
)

public override void SetLength(
    long value
)

Parameters

value
Type: System.Int64
The value at which to set the length.

Exceptions

Exception	Condition
NotSupportedException	The current stream is not resizable and value is larger than the current capacity. -or- The current stream does not support writing.
ArgumentOutOfRangeException	value is negative or is greater than the maximum length of the MemoryStream, where the maximum length is(MaxValue - origin), and origin is the index into the underlying buffer at which the stream starts.

NotSupportedException

The current stream is not resizable and value is larger than the current capacity.

-or-

The current stream does not support writing.

ArgumentOutOfRangeException

value is negative or is greater than the maximum length of the MemoryStream, where the maximum length is(MaxValue - origin), and origin is the index into the underlying buffer at which the stream starts.

Remarks

This method overrides SetLength.

If the specified value is less than the current length of the stream, the stream is truncated. If after the truncation the current position within the stream is past the end of the stream, the ReadByte method returns -1, the Read method reads zero bytes into the provided byte array, and Write and WriteByte methods append specified bytes at the end of the stream, increasing its length. If the specified value is larger than the current capacity and the stream is resizable, the capacity is increased, and the current position within the stream is unchanged. If the length is increased, the contents of the stream between the old and the new length are initialized to zeros.

Note:
A MemoryStream instance must support writing for this method to work. Use the CanWrite property to determine whether the current instance supports writing. For additional information, see CanWrite.

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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