C# 什么'；在所有者绘制的列表框中使用控件的正确方法是什么？

我正在试验所有者绘制的列表框。我正在向列表框中的特定项添加文本框。但是，当我开始滚动时，文本框不会显示在正确的位置。正确的方法是什么？ 这是我正在使用的代码

Form1.cs

Program.cs

---

编辑为了更清楚，我重新写了我的答案

下面的列表框显示一个文本框及其SelectedItem

GetItemRectangle(int index) 

用于检索列表框中项目的当前位置。这似乎是你正在寻找的关键方法

public class ListBoxEx : ListBox
{
    public ListBoxEx()
    {
        TextBox.Visible = false;
        Controls.Add(TextBox);
    }

    private readonly Size TextBoxOffset = new Size(16, 16);
    private const Int32 CellHeight = 40;
    private readonly TextBox TextBox = new TextBox();

    protected override void OnSelectedIndexChanged(EventArgs e)
    {
        base.OnSelectedIndexChanged(e);
        TextBox.Visible = SelectedIndex != -1;
    }

    protected override void OnDrawItem(DrawItemEventArgs e)
    {
        base.OnDrawItem(e);

        // Somehow necessary
        e.Graphics.FillRectangle(new SolidBrush(BackColor), e.Bounds);
        // Drawing the item's text
        e.Graphics.DrawString(Items[e.Index].ToString(), Font, new SolidBrush(ForeColor), e.Bounds);
        // Drawing the item's borders
        e.Graphics.DrawRectangle(new Pen(ForeColor), e.Bounds);

        // Drawing updating the TextBox location 
        if (SelectedIndex != -1)
            TextBox.Location = Point.Add(GetItemRectangle(SelectedIndex).Location, TextBoxOffset);

        // Because clicking the scrollbar sometimes cause the ListBox to hide the TextBox
        TextBox.BringToFront();
        // Making sure the TextBox is redrawn ASAP
        TextBox.Invalidate();
    }

    protected override void OnMeasureItem(MeasureItemEventArgs e)
    {
        base.OnMeasureItem(e);
        e.ItemHeight = CellHeight;
    }
}

---

我同意过度骑行更好。不过，我原来的问题仍然存在。textbox控件的新位置应该是什么？如果我使用e.Bounds计算它，那么我会得到文本框的位置问题。如果我使用绝对值进行计算，则结果是文本框不会显示（或未渲染？）。我的代码在下一个commentvoid listBox1_DrawItem（对象发送者，DrawItemEventArgs e）{PointF displayLocation=new PointF（20，e.Index*cellHeight+3）；Debug.Print（“DrawItem:：Index={0}，bounds={1}”，e.Index，e.bounds）；e.Graphics.DrawString（this.listBox1.Items[e.Index].ToString（），displayFont，displayBrush，e.Bounds）；e.Graphics.DrawRectangle（displayPen，e.Bounds）；if（e.Index==3）{listBox1.Controls.Clear（）；//item3Text.Location=新点（10，e.Bounds.Y+18）；item3Text.Location=新点（10，e.Index*cellHeight+18）；Debug.Print(“DrawItem:：location={0}”，item3Text.location）；item3Text.Focus（）；item3Text.BringToFront（）；}}}我相信您要查找的方法是ListBox.GetItemRectangle（请参阅我编辑过的答案）。

namespace ListBoxControlScrollIssue
{
    partial class Form1
    {
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }
            base.Dispose(disposing);
        }

        #region Windows Form Designer generated code

        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
        {
        }

        #endregion

    }
}

GetItemRectangle(int index) 

public class ListBoxEx : ListBox
{
    public ListBoxEx()
    {
        TextBox.Visible = false;
        Controls.Add(TextBox);
    }

    private readonly Size TextBoxOffset = new Size(16, 16);
    private const Int32 CellHeight = 40;
    private readonly TextBox TextBox = new TextBox();

    protected override void OnSelectedIndexChanged(EventArgs e)
    {
        base.OnSelectedIndexChanged(e);
        TextBox.Visible = SelectedIndex != -1;
    }

    protected override void OnDrawItem(DrawItemEventArgs e)
    {
        base.OnDrawItem(e);

        // Somehow necessary
        e.Graphics.FillRectangle(new SolidBrush(BackColor), e.Bounds);
        // Drawing the item's text
        e.Graphics.DrawString(Items[e.Index].ToString(), Font, new SolidBrush(ForeColor), e.Bounds);
        // Drawing the item's borders
        e.Graphics.DrawRectangle(new Pen(ForeColor), e.Bounds);

        // Drawing updating the TextBox location 
        if (SelectedIndex != -1)
            TextBox.Location = Point.Add(GetItemRectangle(SelectedIndex).Location, TextBoxOffset);

        // Because clicking the scrollbar sometimes cause the ListBox to hide the TextBox
        TextBox.BringToFront();
        // Making sure the TextBox is redrawn ASAP
        TextBox.Invalidate();
    }

    protected override void OnMeasureItem(MeasureItemEventArgs e)
    {
        base.OnMeasureItem(e);
        e.ItemHeight = CellHeight;
    }
}