C # Advanced Programming 82-day----user-defined exception class

User-defined Exception class

There have been a lot of questions about anomalies , and now it's time to give you a why did about what you're doing when you define an exception .

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Why do you have to define your own exception class ?

Use your toes and make sure , is to define our own anomalies. , you define the exception class to inherit from applicationexception?

The first exception (Exception) is divided into two categories , One is the exception class defined in advance , and the latter is the class to inherit when the user defines the exception class. .

Case :

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Using? System;

Using? System.Collections.Generic;

Using? System.Linq;

Using? System.Text;

Using? System.Threading.Tasks;

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Namespace? define the exception class yourself

{

???? Class? Program

???? {

???????? Static?void? Main (String[]?args)

???????? {

???????????? or the case of the previous sentence?

???????????? Console.WriteLine (" Enter a number from 0 to 5 :?");

???????????? Try

???????????? {

???????????????? you must have known that.

???????????????? If you don't know , You can check out the meaning of Parse , and don't expect me to say anything. !

???????????????? Int?num?=?int. Parse (Console.ReadLine ());

???????????????? If? (num?<?0?| |? NUM?>?5)

???????????????? {

???????????????????? Throw?new? MyException (" Are you funny ? ? " tease me. ?

");

????????????????}

????????????}

???????????? Catch? (Myexception?ex)

???????????? {

???????????????? Console.WriteLine (ex. Message);

????????????}

???????????? Catch? (Exception?ex)

???????????? {

???????????????? Console.WriteLine (ex. Message);

????????????}

???????????? Finally

???????????? {

???????????????? Console.WriteLine (" I'm still the finally?!? of the Ox X ");????????????

????????????}

???????????? Console.readkey ();

????????}

????}

???? Public?class? MyException?:? ApplicationException?

{

Public? MyException? (){}

???????? Public? MyException (string?message)?:? base (Message)? {?} Do you know what this is about ?

don't tell me you forgot. !!

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???????? Public?override?string? Message

???????? {

???????????? Get

???????????? {

???????????????? Return?base. Message;

????????????}

????????}

????}

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}

Within this, you define the exception class myexception:applicationexception,catch( Myexception?me) user captures their own definition exceptions. catch(exception?e) is used to catch a generic exception, assuming that the exception was caught by the first catch , then the second the catch will not run and run directly in the finally statement.

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Here are a few things to note about the exception classes that you define :

1. Assuming that your exception class is required to write to a file , such as a log , you need to declare the exception class as serializable [Serializable]

2. To implement a non-parameter constructor, a non-parameter exception may be thrown

3. Implement a constructor that includes a message

4. Implement a constructor that includes a message and an inner exception type

5. Add your own from the error identification data member

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So : in general, your own defined format is this

???? Class? MyException?:? ApplicationException

???? {

???????? This is a non-participating constructor , try it .

???????? Public? MyException ()

???????? {?}

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???????? Public? MyException (String?message)

????????????:? Base (Message)

???????? {?}

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???????? Public? MyException (String?message,? Exception?inner)

????????????:? Base (Message,?inner)

???????? {?}

????}

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C # Advanced Programming 82-day----user-defined exception class