为什么在向自定义控件添加新属性时不显示属性？

Question

I have a library class and i added a new User Control and added a code:

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

namespace CustomControl
{
    public partial class ExtendedTextBox : UserControl
    {
        [PropertyTab("Data")]
        [Browsable(true)]
        [Category("Extended Properties")]
        [Description("Set TextBox border Color")]

        public string Texts
        {
            get { return textBox.Text; }
            set { textBox.Text = value; }
        }

        private TextBox textBox;

        public ExtendedTextBox()
        {
            InitializeComponent();

            textBox = new TextBox();
            textBox.Multiline = true;
            textBox.BorderStyle = BorderStyle.None;
            this.Controls.Add(textBox);
        }

        private void ExtendedTextBox_Load(object sender, EventArgs e)
        {

        }

        private void ExtendedTextBox_Paint(object sender, PaintEventArgs e)
        {
            ControlPaint.DrawBorder(e.Graphics, this.ClientRectangle, Color.Red, ButtonBorderStyle.Solid);
        }

        private void ExtendedTextBox_Resize(object sender, EventArgs e)
        {
            textBox.Size = new Size(this.Width - 3, this.Height - 2);
            textBox.Location = new Point(2, 1);
        }
    }
}

When i add the dll file to another windows forms project i drag the control to the designer but in the solution explorer under the control properties i don't see Data and not Extended Properties and not Set TextBox border Color.

I wanted to add a property that when you click on it will give you a sub property and click on that will open the colors pattern so you can change/set a new color to the paint event.

Now in the paint event it's set to Red but i want that there will be a property so the user can set any color.

Answer 1

Where is property that stores textBox border color? I see only public string Texts property. You should add new property for textBox border:

[PropertyTab("Data")]
[Browsable(true)]
[Category("Extended Properties")]
[Description("Set TextBox border Color")]
public Color BorderColor { get; set; }

Answer 2

Where are you defining the Data class that inherits PropertyTab ? If you are not defining it yourself, what Data class did you expect for the designer to use?

The other attributes — Category and Description — work fine for me. The custom property is shown in the "Properties" tab of the PropertyGrid control, in its own "Extended Properties" category (naturally, you have to be grouping properties by category, not alphabetically), with the correct description text (shown when the property is selected in the PropertyGrid ).

The PropertyTab attribute has to specify a valid PropertyTab class. If you don't have a Data class for it to use, then obviously the property can't be displayed in the Data class's property tab.

Answer 3

Not so understand what you tried. But works great for me, after some changes are needed in your code.

public partial class ExtendedTextBox : UserControl
{
    [PropertyTab("Data")]
    [Browsable(true)]
    [Category("Extended Properties")]
    [Description("Set TextBox border Color")]
    public Color BorderColor { get; set; }

    [PropertyTab("Data")]
    [Browsable(true)]
    [Category("Extended Properties")]
    [Description("Set TextBox Text")]
    public string Texts
    {
        get { return textBox.Text; }
        set { textBox.Text = value; }
    }

    private TextBox textBox;

    public ExtendedTextBox()
    {
        textBox = new TextBox();
        textBox.Multiline = true;
        textBox.BorderStyle = BorderStyle.None;
        this.Controls.Add(textBox);
    }

    protected override void OnPaint(PaintEventArgs e)
    {
        base.OnPaint(e);
        ControlPaint.DrawBorder(e.Graphics, this.ClientRectangle, BorderColor, ButtonBorderStyle.Solid);
    }

    protected override void OnResize(EventArgs e)
    {
        base.OnResize(e);
        textBox.Size = new Size(this.Width - 3, this.Height - 2);
        textBox.Location = new Point(2, 1);
    }
}

EDIT: For apply changes immediately you need refresh the control BorderColor property on catch the moment of set, which is not possible automatic property, but only full property. so:

//private field needy in full property.
private Color _BorderColor = Color.Red;  //= Color.Red; for default color...

[PropertyTab("Data")]
[Browsable(true)]
[Category("Extended Properties")]
[Description("Set TextBox border Color")]
public Color BorderColor
{
    get {return _BorderColor ;}
    set
    {
        _BorderColor = value;
        Invalidate(); //refresh, trigger new paint.
    }
}