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XmlTextReader.ReadElementContentAsBase64(Byte[], Int32, Int32) Method

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Definition

Namespace:
System.Xml
Assembly:
System.Xml.ReaderWriter.dll
Assembly:
System.Xml.dll
Assembly:
netstandard.dll
Source:
XmlTextReader.cs
Source:
XmlTextReader.cs
Source:
XmlTextReader.cs

Reads the element and decodes the Base64 content.

public:
 override int ReadElementContentAsBase64(cli::array <System::Byte> ^ buffer, int index, int count);
public override int ReadElementContentAsBase64 (byte[] buffer, int index, int count);
override this.ReadElementContentAsBase64 : byte[] * int * int -> int
Public Overrides Function ReadElementContentAsBase64 (buffer As Byte(), index As Integer, count As Integer) As Integer

Parameters

buffer
Byte[]

The buffer into which to copy the resulting text. This value cannot be null.

index
Int32

The offset into the buffer where to start copying the result.

count
Int32

The maximum number of bytes to copy into the buffer. The actual number of bytes copied is returned from this method.

Returns

Int32

The number of bytes written to the buffer.

Exceptions

ArgumentNullException

The buffer value is null.

InvalidOperationException

The current node is not an element node.

ArgumentOutOfRangeException

The index into the buffer or index + count is larger than the allocated buffer size.

NotSupportedException

The XmlTextReader implementation does not support this method.

XmlException

The element contains mixed-content.

FormatException

The content cannot be converted to the requested type.

Examples

See XmlReader.ReadElementContentAsBase64 to see an example using this method.

Remarks

Note

Starting with the .NET Framework 2.0, we recommend that you create XmlReader instances by using the XmlReader.Create method to take advantage of new functionality.

This method reads the element content, decodes it using Base64 encoding, and returns the decoded binary bytes (for example, an inline Base64 encoded GIF image) into the buffer. For more information, see RFC 1521, "MIME (Multipurpose Internet Mail Extensions) Part One: Mechanisms for Specifying and Describing the Format of Internet Message Bodies". You can obtain RFCs from the Request for Comments Web site.

This method can only read simple-content elements. The element can contain text, white space, significant white space, CDATA sections, comments and processing instructions. It can also contain entity references, which are automatically expanded. The element cannot have child elements.

This method is very similar to the ReadContentAsBase64 method except that it can only be called on element node types.

If the count value is higher than the number of bytes in the document, or if it is equal to the number of bytes in the document, the XmlTextReader reads all the remaining bytes in the document and returns the number of bytes read. The next XmlTextReader method call returns a zero and moves the reader to the node following the EndElement.

If you call Read before all of the element content is consumed, the reader may behave as if the first content was consumed and then the Read method was called. This means that the reader reads all the text until the end element is encountered. It then reads the end tag node, reads the next node, and then positions itself on the next subsequent node.

Applies to

See also