我如何添加一些属性到UserControl

本文关键字：属性 UserControl 添加 何添加 | 更新日期: 2023-09-27 17:49:49

我有一个listBox的UserControl:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace Lightnings_Extractor
{
    public partial class ListBoxControl : UserControl
    {
        private List<int> m_itemIndexes = new List<int>();
        public ListBoxControl()
        {
            InitializeComponent();
            this.listBox1.SelectedIndex = 0;
        }
        private void listBox1_MouseDown(object sender, MouseEventArgs e)
        {
            int index = listBox1.IndexFromPoint(e.X, e.Y);
            listBox1.SelectedIndex = index;
            if (e.Button == System.Windows.Forms.MouseButtons.Right)
            {
                if (m_itemIndexes.Contains(index))
                    return;
                m_itemIndexes.Add(index);
                DrawItem(index);
            }
            else if (e.Button == MouseButtons.Left)
            {
                if (!m_itemIndexes.Contains(index))
                    return;
                m_itemIndexes.Remove(index);
                DrawItem(index);
            }
        }
        private void listBox1_DrawItem(object sender, DrawItemEventArgs e)
        {
            bool coloring = m_itemIndexes.Contains(e.Index);
            bool selected = (e.State & DrawItemState.Selected) == DrawItemState.Selected;
            if (coloring)
            {
                using (var brush = new SolidBrush(Color.Red))
                {
                    e.Graphics.FillRectangle(brush, e.Bounds);
                }
            }
            else
            {
                e.DrawBackground();
            }
            string item = listBox1.Items[e.Index].ToString();
            e.Graphics.DrawString(item, e.Font, selected || coloring ? Brushes.White : Brushes.Black, e.Bounds, StringFormat.GenericDefault);
            if (selected)
                e.DrawFocusRectangle();
        }
        private void DrawItem(int index)
        {
            Rectangle rectItem = listBox1.GetItemRectangle(index);
            listBox1.Invalidate(rectItem);
        }
    }
}

例如这行:

using (var brush = new SolidBrush(Color.Red))

现在它设置为红色。但我希望用户能够改变它的任何颜色在任何地方在他的代码或在另一种形式或类。不仅在这个UserControl代码中。

我如何添加一些属性到UserControl

就像平常那样声明一个属性:

[Browsable(true)] //so it appears in object explorer
public Color MyListColor
{
  get { return m_MyListColor;}
  set 
  {
    m_MyListColor = value;
    Refresh();//or Update
  }
}

一旦你将属性设置为新值，它会调用Refresh()来重新绘制控件，包括你的画笔。

只需添加一个新属性。

public Brush Fill {get;set;}
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