KOZ60

using System;
using System.Collections.Generic;
using System.Reflection;
using System.Runtime.Remoting;
using System.Runtime.Remoting.Messaging;
using System.Runtime.Remoting.Proxies;
using System.Diagnostics;

static class UTL
{

KOZ60

1.SetClipboardViewer

Imports System.Runtime.InteropServices

Public Class Form1

    Private hwndNextChain As IntPtr

    Public Sub New()

KOZ60

Would you like to try using NetOfficeFw.Excel? You can get it from nuget.

https://www.nuget.org/packages/NetOfficeFw.Excel

1. There is no need to write Marshal.ReleaseComObject at all. All objects implement IDisposable, and when you Dispose them, they are released internally using ReleaseComObject. Also, if you Dispose the top level NetOffice.ExcelApi.Application, all the objects under it will be released.

2. Since it is late binding, it does not depend on the Office version.

KOZ60

Imports System.Collections
Imports System.Collections.Generic
Imports System.ComponentModel
Imports System.Runtime.InteropServices
Imports System.Windows.Forms

<DefaultEvent("HotkeyPress")>
Public Class Hotkey
    Inherits Component

KOZ60

Imports System.ComponentModel
Imports System.Runtime.InteropServices
Imports System.Windows.Forms

<DesignerCategory("code")>
<DefaultEvent("KeyDown")>
Public Class LowLevelKeyboardHook
    Inherits Component

    Private HookHandle As IntPtr = IntPtr.Zero

KOZ60

Option Strict On
Imports System
Imports System.Diagnostics
Imports System.Runtime.InteropServices
Imports System.Text
Imports System.Windows.Forms

Public Class RestrictText
    Inherits TextBox
    Private Const CTRL_A As Char = ChrW(&H1)    ' CTRL+A (Select All)

KOZ60

using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows.Forms;

public class RestrictText : TextBox
{
    private const char BACKSPACE = '\b';      // Backspace
    private const char CTRL_A = '\x01';       // CTRL+A（Select All）

KOZ60

How to pass a ref string from C# to a DLL

C#

[DllImport("SampleDLL.Dll", CharSet = CharSet.None)]
[return: MarshalAs(UnmanagedType.BStr)]
extern public static string StringTest(
    [MarshalAs(UnmanagedType.BStr)] ref string refString
    );

KOZ60

using System;
using System.ComponentModel;
using System.Collections;
using System.Collections.Generic;
using System.Diagnostics;
using System.Drawing;
using System.Windows.Forms;

[DesignerCategory("code") ]
public class DataGridViewWithFooter : DataGridView

KOZ60

using System;
using System.Drawing;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;

public class DataGridViewSelectAllCheckBoxHeaderCell : DataGridViewColumnHeaderCell
{
    protected static class CheckBoxHeaderCellRenderer
    {
        private static readonly VisualStyleElement CheckBoxElement