c# - Rethrow an exception is this case -

i have this:

public byte[] anymethod(){    try {     ...   }   catch (exception e) {     string errormessage =        "some custom message, should caller of method should receive";      // thought of ,to pass through custom exception caller?!     throw new applicationexception(errormessage);      //but not allow method   }  } 

but this:

throw new applicationexception(errormessage); 

will result in:

an exception of type 'system.applicationexception' occurred in ...dll not handled in user code

how give custom errror message caller of above mentioned method ?

first, use custom exception or @ least 1 more meaningful instead of applicationexception. second, have catch exception if method throws it.

so calling method should wrap method call in try...catch:

try {     byte[] result = anymethod(); }catch(mycustomexception ex) {     // here can access properties of exception, add new properties     console.writeline(ex.message); } catch(exception otherex) {     // other exceptions, useful logging here     throw;  // better throw otherex since keeps original stacktrace  } 

here's abstract, simplified example:

public class mycustomexception : exception {     public mycustomexception(string msg) : base(msg)     {     } }  public byte[] anymethod() {     try     {         return getbytes(); // exception possible     }     catch (exception e)     {         string errormessage = "some custom message, should caller of method should receive";         throw new mycustomexception(errormessage);     } } 

but note should not use exceptions normal program flow. instead either return true or false indicate if action successful or use out parameter byte[] int.tryparse(or other tryparse methods).