Why is System.TimeSpan not XML serializable?
c#, serialization, timespan, xml-serialization
Solution
The reason it won't serialize is because `XmlCustomFormatter` doesn't implement the functionality to serialize it.
From the `XmlCustomFormatter` class, here is a list of supported serializable data (from the `FromDefaultValue` method):
`DateTime`
`Date`
`Time`
You can see how it is used to serialize everything if you look at the `XmlSerializationWriter` class in the source reference:
See the `WriteTypedPrimitive` method for more details on primites etc.
/// <include file='doc\XmlSerializationWriter.uex' path='docs/doc[@for="XmlSerializationWriter.WriteTypedPrimitive"]/*' />
protected void WriteTypedPrimitive(string name, string ns, object o, bool xsiType) {
Details on object and xml serialization:
/// <include file='doc\XmlSerializationWriter.uex' path='docs/doc[@for="XmlSerializationWriter.FromByteArrayBase64"]/*' />
protected static byte[] FromByteArrayBase64(byte[] value) {
// Unlike other "From" functions that one is just a place holder for automatic code generation.
// The reason is performance and memory consumption for (potentially) big 64base-encoded chunks
// And it is assumed that the caller generates the code that will distinguish between byte[] and string return types
//
return value;
}
/// <include file='doc\XmlSerializationWriter.uex' path='docs/doc[@for="XmlSerializationWriter.FromByteArrayHex"]/*' />
protected static string FromByteArrayHex(byte[] value) {
return XmlCustomFormatter.FromByteArrayHex(value);
}
/// <include file='doc\XmlSerializationWriter.uex' path='docs/doc[@for="XmlSerializationWriter.FromDateTime"]/*' />
protected static string FromDateTime(DateTime value) {
return XmlCustomFormatter.FromDateTime(value);
}
/// <include file='doc\XmlSerializationWriter.uex' path='docs/doc[@for="XmlSerializationWriter.FromDate"]/*' />
protected static string FromDate(DateTime value) {
return XmlCustomFormatter.FromDate(value);
}
/// <include file='doc\XmlSerializationWriter.uex' path='docs/doc[@for="XmlSerializationWriter.FromTime"]/*' />
protected static string FromTime(DateTime value) {
return XmlCustomFormatter.FromTime(value);
}
/// <include file='doc\XmlSerializationWriter.uex' path='docs/doc[@for="XmlSerializationWriter.FromChar"]/*' />
protected static string FromChar(char value) {
return XmlCustomFormatter.FromChar(value);
}
/// <include file='doc\XmlSerializationWriter.uex' path='docs/doc[@for="XmlSerializationWriter.FromEnum"]/*' />
protected static string FromEnum(long value, string[] values, long[] ids) {
return XmlCustomFormatter.FromEnum(value, values, ids, null);
}
/// <include file='doc\XmlSerializationWriter.uex' path='docs/doc[@for="XmlSerializationWriter.FromEnum1"]/*' />
protected static string FromEnum(long value, string[] values, long[] ids, string typeName) {
return XmlCustomFormatter.FromEnum(value, values, ids, typeName);
}
/// <include file='doc\XmlSerializationWriter.uex' path='docs/doc[@for="XmlSerializationWriter.FromXmlName"]/*' />
protected static string FromXmlName(string name) {
return XmlCustomFormatter.FromXmlName(name);
}
/// <include file='doc\XmlSerializationWriter.uex' path='docs/doc[@for="XmlSerializationWriter.FromXmlNCName"]/*' />
protected static string FromXmlNCName(string ncName) {
return XmlCustomFormatter.FromXmlNCName(ncName);
}
/// <include file='doc\XmlSerializationWriter.uex' path='docs/doc[@for="XmlSerializationWriter.FromXmlNmToken"]/*' />
protected static string FromXmlNmToken(string nmToken) {
return XmlCustomFormatter.FromXmlNmToken(nmToken);
}
/// <include file='doc\XmlSerializationWriter.uex' path='docs/doc[@for="XmlSerializationWriter.FromXmlNmTokens"]/*' />
protected static string FromXmlNmTokens(string nmTokens) {
return XmlCustomFormatter.FromXmlNmTokens(nmTokens);
}
Problem
When I try to store a TimeSpan value into ApplicationData Settings I get an error because TimeSpan cannot be serialized. This SO question shows how to handle it: How to serialize a TimeSpan to XML Why is it that TimeSpan would not be easily serializable? And, is there a list of data types that cannot be serialized?