Unless this attribute is overridden, all classes that inherit from this class use the same type converter as the base class. For general type system purposes, do not access a type converter directly. Instead, access the appropriate converter by using TypeDescriptor. For more information, see the code examples provided. For cases where you do want a TypeDescriptor instance from code, or where you create a shared instance in WPF resources, it is acceptable to construct it directly without referencing TypeDescriptor or other reflection and type system support.
Classes derived from TypeConverter are often referenced as part of how a XAML processor converts an attribute or initialization text value from markup which is inherently a string and generates an object for a run-time representation. Custom type authors that intend to support a type conversion behavior for XAML typically implement a TypeConverter class that supports their own unique ConvertFrom behavior from a string.
This behavior enables type conversion from the string provided as a XAML attribute value and provides a XAML processor with the support needed to create an object from the string, so that the object can be produced in a parsed object graph.
Custom types or members of custom types are indicated by applying TypeConverterAttribute to the definitions, with the attribute referencing the custom TypeConverter implementation.
Inherit from TypeConverter to implement your own conversion requirements. When you inherit from this class, you can override the following methods:. If the class you are converting does not have properties, and you need to implement properties, you can use the TypeConverter. SimplePropertyDescriptor class as a base for implementing the property descriptors. When you inherit from TypeConverter.
Note: Your derived type might be marked as internal or private , but an instance of your type can be created with the TypeDescriptor class. Do not write insecure code by assuming the caller is trusted. Assume instead that callers might create instances of your type in partial trust. Initializes a new instance of the TypeConverter class.
Returns whether this converter can convert an object of the given type to the type of this converter, using the specified context. Returns whether this converter can convert an object of the given type to the type of this converter. Returns whether this converter can convert the object to the specified type, using the specified context. Converts the given object to the type of this converter, using the specified context and culture information.
Converts the given string to the type of this converter, using the invariant culture and the specified context. Converts the given value object to the specified type, using the specified context and culture information. Converts the specified value to a culture-invariant string representation, using the specified context. Converts the given value to a string representation, using the specified context and culture information. Re-creates an Object given a set of property values for the object.
Creates an instance of the type that this TypeConverter is associated with, using the specified context, given a set of property values for the object. Returns whether changing a value on this object requires a call to the CreateInstance IDictionary method to create a new value.
Returns whether changing a value on this object requires a call to CreateInstance IDictionary to create a new value, using the specified context. Sometimes we need to check if string contains only alphabet in c , for example, when we accept some name, which should not contain any number of any other character other than alphabet.
Check if C string contains only letter or digit , situation like allowing user to create unique username, which can contain only alphabet or number, no other character accepted, in such scenario following validation will work.
Net Asp. Net Core C. Net C. Net Web API. C String validation example, check if string input is in expected format using c syntax. IgnoreCase ;. No custom type converter necessary. Eric Hauser. We use type convertors extensively in our config classes to ensure that the pesky strings in the config files will be converted to the actual types like Regex or Color, when they enter the process. Much cleaner for me, that playing with X tra ML. Rajiv Das. Eric - Does that work with types that DO have custom converters?
Does it work for typeof T? Dragan - Thanks! My source code formatter is wonky for generics. I'll fix it tonight. May 12, Mojtaba Vali. I have to admit that I don't really care for TypeConverters, though my experience with them has been with trying to do some fairly complicated things within Visual Studio to get my components to work the way I want them in the designer.
I think they could have designed the type converters a little differently and perhaps separated out some of the other work the TypeConverters also do such as getting a list of valid values. This blog post motivated me into creating a blog post of my own.
My article discusses three different methods of converting values IConvertible, TypeConverters, and conversion methods as well as provides a sample project that includes source code that is similar to System. ChangeType but can also handle TypeConverters and conversion methods.
Here is the link to the article if you are interested - Type Conversions. Brian Brewder. ConvertFromString will throw a FormatException. Otherwise very useful article! Thanks for brings this to attention, Scott!
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