Tips on DLL components that cannot be placed in the toolbox

Public class mylistview: system. Windows. Forms. listview
{

....

}

If public is removed, dll can also be generated, but when you add it to the user control, a prompt will be displayed: e:/mylistview/bin/mylistview. DLL does not have any components that can be placed on the toolbox.

 

2. The control needs to have its own empty constructor. Even if there is a constructor with parameters, there should be empty constructor.

View code

using System;using System.Collections.Generic;using System.Linq;using System.Text;using System.ComponentModel;using System.Windows.Forms;using System.Drawing;namespace CustomControlSample{    public class FirstControl : Control    {        public FirstControl()        {        }        private ContentAlignment alignmentValue = ContentAlignment.MiddleLeft;        [        Category("Alignment"),        Description("Specifies the alignment of text.")        ]        public ContentAlignment TextAlignment        {            get { return alignmentValue; }            set             {                alignmentValue = value;                Invalidate();            }        }        protected override void OnPaint(PaintEventArgs e)        {            base.OnPaint(e);            StringFormat style = new StringFormat();            style.Alignment = StringAlignment.Near;            switch (alignmentValue)            {                case ContentAlignment.MiddleLeft:                    style.Alignment = StringAlignment.Near;                    break;                case ContentAlignment.MiddleRight:                    style.Alignment = StringAlignment.Far;                    break;                case ContentAlignment.MiddleCenter:                    style.Alignment = StringAlignment.Center;                    break;            }            e.Graphics.DrawString(                Text,                Font,                new SolidBrush(ForeColor),                ClientRectangle, style);        }    }}