XmlReader.ReadElementContentAsBase64 Method
[ This article is for Windows Phone 8 developers. If you’re developing for Windows 10, see the latest documentation. ]
Reads the element and decodes the Base64 content.
Assembly: System.Xml (in System.Xml.dll)
Parameters
- buffer
- Type:
System.Byte
[]
The buffer into which to copy the resulting text. This value cannot be null.
- index
- Type: System.Int32
The offset into the buffer where to start copying the result.
- count
- Type: System.Int32
The maximum number of bytes to copy into the buffer. The actual number of bytes copied is returned from this method.
| Exception | Condition |
|---|---|
| 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 XmlReader implementation does not support this method. |
| XmlException | The element contains mixed-content. |
| FormatException | The content cannot be converted to the requested type. |
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.
ReadElementContentAsBase64 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 XmlReader reads all the remaining bytes in the document and returns the number of bytes read. The next XmlReader 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 will read all the text until the end element is encountered. It will then read the end tag node, read the next node, and then position itself on the next subsequent node.
Note: |
|---|
The item delimiter for arrays is a single space. When deserializing arrays of type string, object, byte[], and Uri, the resulting array will contain an empty string value for any sequence of two delimiters (spaces) between non-empty values. For example, "a b", with two spaces, is deserialized as ["a", "", "b"]. This is different from other .NET Framework behavior and from all the other array types in which the empty values are ignored. You can use the following work-around to remove empty spaces: 1. Get the content as one big string instead of a string array from ReadContentAsString. 2. Use the System.String.Split method with StringSplitOptions.RemoveEmptyEntities to convert the big string into a string array. 3. Work with the resulting string array or convert each item further, for example, to Uri. |
Note: