请问如何显示单元格

Question

请问如何在combobox的下拉框中 显示出单元格。（类似于datagrid中的 小格子）
谢谢。

Answer 1

你可以参考ComboBox.DrawMode 属性，
获取或设置一个值，该值指示是由您的代码还是由操作系统来处理列表中的元素的绘制。下面的代码示例演示如何创建所有者描述的组合框，具体方法为将 DrawMode 属性设置为 OwnerDrawnVariable，并处理 DrawItem 和 MeasureItem 事件。它还阐释了如何设置 DropDownWidth 和 DropDownStyle 属性。要运行该示例，请将以下代码粘贴到一个窗体中。在该窗体的构造函数或 Load 事件中调用 InitializeComboBox 方法。internal System.Windows.Forms.ComboBox ComboBox1;
private string[] animals;
  
// This method initializes the owner-drawn combo box.
// The drop-down width is set much wider than the size of the combo box
// to accomodate the large items in the list.  The drop-down style is set to 
// ComboBox.DropDown, which requires the user to click on the arrow to 
// see the list.
private void InitializeComboBox()
{
    this.ComboBox1 = new ComboBox();
    this.ComboBox1.DrawMode = 
        System.Windows.Forms.DrawMode.OwnerDrawVariable;
    this.ComboBox1.Location = new System.Drawing.Point(10, 20);
    this.ComboBox1.Name = "ComboBox1";
    this.ComboBox1.Size = new System.Drawing.Size(100, 120);
    this.ComboBox1.DropDownWidth = 250;
    this.ComboBox1.TabIndex = 0;
    this.ComboBox1.DropDownStyle = ComboBoxStyle.DropDown;
    animals = new string[]{"Elephant", "c r o c o d i l e", "lion"};
    ComboBox1.DataSource = animals;
    this.Controls.Add(this.ComboBox1);    // Hook up the MeasureItem and DrawItem events
    this.ComboBox1.DrawItem += 
        new DrawItemEventHandler(ComboBox1_DrawItem);
    this.ComboBox1.MeasureItem += 
        new MeasureItemEventHandler(ComboBox1_MeasureItem);
}// If you set the Draw property to DrawMode.OwnerDrawVariable, 
// you must handle the MeasureItem event. This event handler 
// will set the height and width of each item before it is drawn. 
private void ComboBox1_MeasureItem(object sender, 
    System.Windows.Forms.MeasureItemEventArgs e)
{    switch(e.Index)
    {
        case 0:
            e.ItemHeight = 45;
            break;
        case 1:
            e.ItemHeight = 20;
            break;
        case 2:
            e.ItemHeight = 35;
            break;
    }
    e.ItemWidth = 260;}// You must handle the DrawItem event for owner-drawn combo boxes.  
// This event handler changes the color, size and font of an 
// item based on its position in the array.
private void ComboBox1_DrawItem(object sender, 
    System.Windows.Forms.DrawItemEventArgs e)
{    float size = 0;
    System.Drawing.Font myFont;
    FontFamily family = null;    System.Drawing.Color animalColor = new System.Drawing.Color();
    switch(e.Index)
    {
        case 0:
            size = 30;
            animalColor = System.Drawing.Color.Gray;
            family = FontFamily.GenericSansSerif;
            break;
        case 1:
            size = 10;
            animalColor = System.Drawing.Color.LawnGreen;
            family = FontFamily.GenericMonospace;
            break;
        case 2:
            size = 15;
            animalColor = System.Drawing.Color.Tan;
            family = FontFamily.GenericSansSerif;
            break;
    }    // Draw the background of the item.
    e.DrawBackground();    // Create a square filled with the animals color. Vary the size
    // of the rectangle based on the length of the animals name.
    Rectangle rectangle = new Rectangle(2, e.Bounds.Top+2, 
            e.Bounds.Height, e.Bounds.Height-4);
    e.Graphics.FillRectangle(new SolidBrush(animalColor), rectangle);    // Draw each string in the array, using a different size, color,
    // and font for each item.
    myFont = new Font(family, size, FontStyle.Bold);
    e.Graphics.DrawString(animals[e.Index], myFont, System.Drawing.Brushes.Black, new RectangleF(e.Bounds.X+rectangle.Width, e.Bounds.Y, e.Bounds.Width, e.Bounds.Height));    // Draw the focus rectangle if the mouse hovers over an item.
    e.DrawFocusRectangle();
}

Answer 2

按楼主的要求，大致应是这样的：
private void initCom()
{
this.comboBox1.DrawMode = System.Windows.Forms.DrawMode.OwnerDrawVariable;
this.comboBox1.FormattingEnabled = true;
this.comboBox1.Items.AddRange(new object[] {
            "abcdefg",
            "bcdefgh",
            "cdefghi",
            "defghij",
            "efghijk",
            "fghijkl",
            "ghijklm"});
this.comboBox1.Location = new System.Drawing.Point(37, 100);
this.comboBox1.Name = "comboBox1";
this.comboBox1.Size = new System.Drawing.Size(121, 22);
this.comboBox1.TabIndex = 5;
this.comboBox1.DrawItem += new System.Windows.Forms.DrawItemEventHandler(this.comboBox1_DrawItem);
this.comboBox1.MeasureItem += new System.Windows.Forms.MeasureItemEventHandler(this.comboBox1_MeasureItem); }
private void comboBox1_MeasureItem(object sender, MeasureItemEventArgs e)
{
e.ItemHeight = 20;
e.ItemWidth = 100;
} private void comboBox1_DrawItem(object sender, DrawItemEventArgs e)
{
e.DrawBackground();
e.DrawFocusRectangle();
using (SolidBrush brush = new SolidBrush(e.ForeColor))
{
using (StringFormat format = new StringFormat())
{
format.Alignment = StringAlignment.Near;
format.LineAlignment = StringAlignment.Center;
e.Graphics.DrawString(this.comboBox1.Items[e.Index].ToString(), this.comboBox1.Font, brush, e.Bounds, format);
}
}
using (Pen pen = new Pen(e.ForeColor))
{
e.Graphics.DrawRectangle(pen, e.Bounds);
}
}

Answer 3

感谢您的帮忙，
如果combobox是多列的情况，该如何处理呢？
我写的DrawItem()方法如下，请问该如何 改动， 谢谢。
protected override void OnDrawItem(DrawItemEventArgs e)
        {
            e.DrawBackground();
            if (0 <= e.Index)
            {
                e.Graphics.DrawString(this.m_table.Rows[e.Index][0].ToString(), e.Font, new SolidBrush(e.ForeColor), (float)e.Bounds.X, (float)e.Bounds.Y);
                if (1 < this.m_table.Columns.Count)
                {
                    int x = (base.DropDownWidth - base.Width) / (this.m_table.Columns.Count - 1);
                    if (this.m_table.Columns.Count <= columnLimit)
                    {
                        for (int i = 1; i < this.m_table.Columns.Count; i++)
                        {
                            e.Graphics.DrawString(this.m_table.Rows[e.Index][i].ToString(), e.Font, new SolidBrush(e.ForeColor), (float)(base.Width + (x * (i - 1))), (float)e.Bounds.Y);
                        }
                    }
                    else if (columnLimit < this.m_table.Columns.Count )
                    {
                        for (int i = 1; i < columnLimit; i++)
                        {
                            e.Graphics.DrawString(this.m_table.Rows[e.Index][i].ToString(), e.Font, new SolidBrush(e.ForeColor), (float)(base.Width + (x * (i - 1))), (float)e.Bounds.Y);
                        }
                    } 
                }
            }           e.DrawFocusRectangle();
        }

Answer 4

hbxtlhx 您好：
  仿照您的代码，我实现了 行与行 之间的分割线。
请问 列于列 之间的分割线 该如何添加？