Type. GetType () solution to return null when cross-assembly reflection

This situation is often encountered during development. In Assembly A. dll, the type in assembly B. dll needs to be reflected. A running error occurs if you are not careful with it. For example, if Type. GetType ("BNameSpace. ClassName") is used in Assembly A. dll to obtain the Type in assembly B. dll, Null is returned.

For cross-assembly reflection, pay attention to the following two points:

 

1. If typeof is used, the cross-assembly reflection will certainly run normally. It can be said that typeof supports strong types. For example

1 Type supType = typeof (BNameSpace. SubSpace. Class );

If the current Assembly does not add a reference to EnterpriseServerBase. dll, an error is reported during compilation.

 

2. If Type. GetType is used for reflection, the situation is more complicated. This is because Type. GetType is of a non-strong Type. The Type. GetType parameter is a fully qualified name of the string Type. If the target Type indicated by string is not in the current Assembly, Type. GetType will return null at runtime. Solution: First load the target Assembly, and then use the Assembly. GetType method to obtain the type. For example

1 Assembly asmb = Assembly. LoadFrom ("EnterpriseServerBase. dll ");
2 Type supType = asmb. GetType ("EnterpriseServerBase. DataAccess. IDBAccesser ");

 

Note that when Type. when GetType is used, even if you have added the parameter iseserverbase. dll reference, Type. getType ("EnterpriseServerBase. dataAccess. IDBAccesser ") also returns null because of Type. getType only searches for the type in the current dataset!