Compiler Error CS1061
Visual Studio 2012
'type' does not contain a definition for 'member' and no extension method 'name' accepting a first argument of type 'type' could be found (are you missing a using directive or an assembly reference?).
This error occurs when you try to call a method or access a class member that does not exist.
The following example generates CS1061 because TestClass1 does not have a DisplaySomething method. It does have a method that is called WriteSomething. Perhaps that is what the author of this source code meant to write.
// cs1061.cs public class TestClass1 { // TestClass1 has one method, called WriteSomething. public void WriteSomething(string s) { System.Console.WriteLine(s); } } public class TestClass2 { // TestClass2 has one method, called DisplaySomething. public void DisplaySomething(string s) { System.Console.WriteLine(s); } } public class TestTheClasses { public static void Main() { TestClass1 tc1 = new TestClass1(); TestClass2 tc2 = new TestClass2(); // The following call fails because TestClass1 does not have // a method called DisplaySomething. tc1.DisplaySomething("Hello"); // CS1061 // To correct the error, change the method call to either // tc1.WriteSomething or tc2.DisplaySomething. tc1.WriteSomething("Hello from TestClass1"); tc2.DisplaySomething("Hello from TestClass2"); } }