You can't call a method by specifying the string name alone in a normal straightforward way, you can only do it by using reflection.
Other means will not be dynamic and probably will be a switch flow control that will call the method you need based on a match.
For the following you will need System.Reflection
string methodName = "testVoid";
Type thisType = this.GetType();
MethodInfo theMethod = thisType.GetMethod(methodName);
theMethod.Invoke(this, null);
Source: https://stackoverflow.com/a/540075/303254