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XElement.SetAttributeValue Method

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

Sets the value of an attribute, adds an attribute, or removes an attribute.

Namespace:  System.Xml.Linq
Assembly:  System.Xml.Linq (in System.Xml.Linq.dll)

Syntax

'Declaration
Public Sub SetAttributeValue ( _
    name As XName, _
    value As Object _
)

public void SetAttributeValue(
    XName name,
    Object value
)

Parameters

  • value
    Type: System.Object
    The value to assign to the attribute. The attribute is removed if the value is nulla null reference (Nothing in Visual Basic). Otherwise, the value is converted to its string representation and assigned to the Value property of the attribute.

Exceptions

Exception Condition
ArgumentException

The value is an instance of XObject.

Remarks

This method is designed to make it easy to maintain a list of name/value pairs as a set of attributes. When maintaining the list, you need to add pairs, modify pairs, or delete pairs. If you call this method passing a name that does not exist as an attribute, this method creates an attribute for you. If you call this method passing the name of an existing attribute, this method modifies the value of the attribute to the value that you specify. If you pass nulla null reference (Nothing in Visual Basic) for value, this method removes the attribute.

This method will raise the Changed and the Changing events.

The value is assigned to the attribute with the specified name. If no attribute with the specified name exists, a new attribute is added. If the value is nulla null reference (Nothing in Visual Basic), the attribute with the specified name, if any, is deleted.

For more information, see Maintaining Name/Value Pairs in the .NET Framework documentation.

Examples

The following example creates an element with an attribute. It then uses this method to replace the content of the attribute.

Dim output As New StringBuilder
' Create an element with no content.
Dim root As XElement = <Root/>

' Add some name/value pairs.
root.SetAttributeValue("Att1", 1)
root.SetAttributeValue("Att2", 2)
root.SetAttributeValue("Att3", 3)
output.Append(root)
output.Append(Environment.NewLine)

' Modify one of the name/value pairs.
root.SetAttributeValue("Att2", 22)
output.Append(root)
output.Append(Environment.NewLine)

' Remove one of the name/value pairs.
root.SetAttributeValue("Att3", Nothing)
output.Append(root)
output.Append(Environment.NewLine)


OutputTextBlock.Text = output.ToString()

StringBuilder output = new StringBuilder();
// Create an element with no content.
XElement root = new XElement("Root");

// Add some name/value pairs.
root.SetAttributeValue("Att1", 1);
root.SetAttributeValue("Att2", 2);
root.SetAttributeValue("Att3", 3);
output.Append(root + Environment.NewLine);

// Modify one of the name/value pairs.
root.SetAttributeValue("Att2", 22);
output.Append(root + Environment.NewLine);

// Remove one of the name/value pairs.
root.SetAttributeValue("Att3", null);
output.Append(root + Environment.NewLine);

OutputTextBlock.Text = output.ToString();

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.