Object reference not set to an instance of an object 5
Complete the catch function
It is time to supplement the use of the catch function to make the error message more attractive. Here is the code:
''' <summary>
''' crash test and how to improve your coding
''' </summary>
''' <remarks></remarks>
Public Class Form1
Private Sub Form1_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
End Sub
''' <summary>
''' pressing button1 will crash he program
''' this crash is the typical crashing type for all beginners
''' </summary>
''' <param name="sender"></param>
''' <param name="e"></param>
''' <remarks></remarks>
Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
Dim aString() As String 'declare and array only
Try
'a crash will occur and the code won't be able to handle it
MsgBox(aString(0)) ' you do something with the array and and array is nothing
Catch ex As Exception
MsgBox(ex.StackTrace, MsgBoxStyle.Exclamation, ex.Message) 'add basic error message here
End Try
End Sub
End Class
|
Adding arguments to the function Msgbox, we enrich the MsgBox window. Here's what happens when you run the function and the program crashes:
Now all the functions that you create will have the function Try and catch function. Throughout your catch function, I recommend you use the StackTrace property with the small exclamation icon. Yes, a picture is worth a thousand words, do not forget.
This technique protection code is very simple and only take 4 lines! Use it.
If you like this post, leave a comment or share it.
Hiç yorum yok:
Yorum Gönder