AdvancedHMI Software

General Category => Open Discussion => Topic started by: bachphi on April 20, 2019, 02:29:52 PM

Title: Thread Safe Controls Translation
Post by: bachphi on April 20, 2019, 02:29:52 PM

I am trying to translate some C# codes to VB, it seemed to work, but want to check if it's alright or some improvement ideas.  TIA.

Code: [Select]

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace ThreadSafeControls
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            label1.CustomInvoke(l => l.Text = "Thread Safe Controls");

        }
    }
    public static class MyInvoke
    {
        public static void CustomInvoke<T>(this T @control, Action<T> toPerform) where T : ISynchronizeInvoke
        {
            if (@control.InvokeRequired)
                @control.Invoke(toPerform, new object[] { @control });
            else
                toPerform(@control);
        }
    }
}



and the VB code that I translated :

Code: [Select]


Imports System.Data
Imports System.Drawing
Imports System.Linq
Imports System.Text
Imports System.Threading.Tasks
Imports System.Windows.Forms

Imports System.ComponentModel

Public Class Form1
    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Label1.CustomInvoke(Sub(l) l.Text = "Thread Safe Controls")
    End Sub
End Class

Public Module MyInvoke
    <System.Runtime.CompilerServices.Extension()>
    Public Sub CustomInvoke(Of T As ISynchronizeInvoke)(control As T, toPerform As Action(Of T))
        If control.InvokeRequired Then
            control.Invoke(toPerform, New Object() {control})
        Else
            toPerform(control)
        End If
    End Sub
End Module


Title: Re: Thread Safe Controls Translation
Post by: Archie on April 20, 2019, 03:00:21 PM

Using lambda expressions and extension methods gets into some sophisticated coding techniques, but your code is the correct way to do it.

Title: Event translation
Post by: bachphi on May 03, 2019, 11:09:04 PM

I tried 3 web sites, none are translated correctly:

Code: [Select]

if (bAdd)
            {
                //Add event handlers
                txtSQLServerName.TextChanged += BuildConnectionString;
                btnExecute.Click += btnExecute_Click;
            }
            else
            {
                //Remove event handlers
                txtSQLServerName.TextChanged -= BuildConnectionString;
                btnExecute.Click -= btnExecute_Click;
            }

I believe, they should be like:

Code: [Select]

If bAdd Then
    'Add event handlers
    AddHandler txtSQLServerName.TextChanged,  AddressOf BuildConnectionString
    AddHandler btnExecute.Click, AddressOf btnExecute_Click

Else
    'Remove event handlers
    RemoveHandler txtSQLServerName.TextChanged, AddressOf BuildConnectionString
    RemoveHandler btnExecute.Click, AddressOf btnExecute_Click
End If


Title: Re: Thread Safe Controls Translation
Post by: Archie on May 04, 2019, 01:59:16 AM

I'm surprised the code converters do not properly convert such as common function, but your conversion is correct.

Title: Form Events order
Post by: bachphi on May 04, 2019, 11:33:44 PM

In C# application, any sub routines that put after InitializeComponent() will get execute BEFORE form_move and form_load events.

How can I get this same effect in vb .net?  TIA.

Title: Re: Thread Safe Controls Translation
Post by: bachphi on May 04, 2019, 11:46:57 PM

I found the answer, use the drop down and select new

Code: [Select]

Public Sub New()

        ' This call is required by the designer.
        InitializeComponent()
        DoEventFirst()

        ' Add any initialization after the InitializeComponent() call.

    End Sub