如何重载ComboBox 使其下拉按钮（带下箭头的）和下拉列表的垂直滚动条的宽度改变？（自绘ComboBox） [转]

原文地址：http://bbs.csdn.net/topics/390135022

http://blog.csdn.net/scsdn/article/details/4363299

想使用winform的combox控件，但是觉得控件太小了，想在触摸屏上使用，感觉combox后面的下拉选择的三角形太小了，combox的宽度也太小了，请问下，combox的这些属性，可以更改吗？能够使小三角形大一些嘛？能够使combox的宽度宽些不？请大家给予帮助，谢谢

设置字体可以使得combobox变大。

combobox,listview等一些控件的外观会由于字体大小的改变而改变。

这个没办法。
除非重绘
http://blog.csdn.net/scsdn/article/details/4363299

关于如何重载ComboBox 使其下拉按钮（带下箭头的）和下拉列表的垂直滚动条的宽度改变的问题，通过自绘自定义控件得以解决。

ComboBoxDIY.cs文件

1. //ComboBoxDIY.cs
2. using System;
3. using System.Collections.Generic;
4. using System.ComponentModel;
5. using System.Drawing;
6. using System.Data;
7. using System.Text;
8. using System.Windows.Forms;
9. namespace WindowsApplication7
10. {
11. public partial class ComboBoxDIY : UserControl
12. {
13. public bool buttondown = false;
14. public ComboBoxDIY()
15. {
16. InitializeComponent();
17. this.listBox1.Visible = false;
18. this.vScrollBar1.Visible = false;
19. }
20. private void button1_Click(object sender, EventArgs e)
21. {
22. //下拉按钮未曾按下
23. if (this.buttondown==false)
24. {
25. //listbox所有数据的项数
26. int count = this.listBox1.Items.Count;
27. //获取listbox所能显示的项数
28. int displaycount = this.listBox1.Height / this.listBox1.ItemHeight;
29. //滚动条显示的最大值
30. int scrollmax = 0;
31. //垂直方向上显示内容数目大于所能显示的数目时
32. //垂直滚动条直接可见
33. if (count > displaycount)
34. {
35. scrollmax = count – 1;
36. this.vScrollBar1.Visible = true;
37. }
38. this.vScrollBar1.LargeChange = displaycount;
39. this.vScrollBar1.Maximum = scrollmax;
40. this.vScrollBar1.Minimum = 0;
41. this.vScrollBar1.Scroll += new ScrollEventHandler(vscroll);
42. this.listBox1.Visible = true;
43. //下拉按钮按下
44. this.buttondown = true;
45. }
46. //下拉按钮已按下
47. else
48. {
49. if(this.vScrollBar1.Visible)this.vScrollBar1.Visible = false;
50. this.listBox1.Visible = false;
51. //下拉按钮弹起
52. this.buttondown = false;
53. }
54. }
55. private void vscroll(object sender, ScrollEventArgs e)
56. {
57. //ScrollBar控制listBox滚动
58. this.listBox1.TopIndex=e.NewValue;
59. }
60. private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
61. {
62. //文本框显示选择结果
63. this.textBox1.Text =this.listBox1.Items[this.listBox1.SelectedIndex].ToString();
64. this.vScrollBar1.Visible = false;
65. this.listBox1.Visible = false;
66. //下拉按钮弹起
67. this.buttondown = false;
68. }
69. }
70. }

//ComboBoxDIY.cs
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Text;
using System.Windows.Forms;

namespace WindowsApplication7
{
public partial class ComboBoxDIY : UserControl
{
public bool buttondown = false;
public ComboBoxDIY()
{
InitializeComponent();
this.listBox1.Visible = false;
this.vScrollBar1.Visible = false;
}

private void button1_Click(object sender, EventArgs e)
{
//下拉按钮未曾按下
if (this.buttondown==false)
{
//listbox所有数据的项数
int count = this.listBox1.Items.Count;
//获取listbox所能显示的项数
int displaycount = this.listBox1.Height / this.listBox1.ItemHeight;
//滚动条显示的最大值
int scrollmax = 0;
//垂直方向上显示内容数目大于所能显示的数目时
//垂直滚动条直接可见
if (count > displaycount)
{
scrollmax = count – 1;
this.vScrollBar1.Visible = true;
}
this.vScrollBar1.LargeChange = displaycount;
this.vScrollBar1.Maximum = scrollmax;
this.vScrollBar1.Minimum = 0;
this.vScrollBar1.Scroll += new ScrollEventHandler(vscroll);

this.listBox1.Visible = true;
//下拉按钮按下
this.buttondown = true;
}
//下拉按钮已按下
else
{
if(this.vScrollBar1.Visible)this.vScrollBar1.Visible = false;
this.listBox1.Visible = false;
//下拉按钮弹起
this.buttondown = false;
}
}

private void vscroll(object sender, ScrollEventArgs e)
{
//ScrollBar控制listBox滚动
this.listBox1.TopIndex=e.NewValue;
}

private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
{
//文本框显示选择结果
this.textBox1.Text =this.listBox1.Items[this.listBox1.SelectedIndex].ToString();
this.vScrollBar1.Visible = false;
this.listBox1.Visible = false;
//下拉按钮弹起
this.buttondown = false;
}
}
}

ComboBoxDIY.Designer.cs文件

1. //ComboBoxDIY.Designer.cs
2. namespace WindowsApplication7
3. {
4. partial class ComboBoxDIY
5. {
6. /// <summary>
7. /// 必需的设计器变量。
8. /// </summary>
9. private System.ComponentModel.IContainer components = null;
10. /// <summary>
11. /// 清理所有正在使用的资源。
12. /// </summary>
13. /// <param name=”disposing”>如果应释放托管资源，为 true；否则为 false。</param>
14. protected override void Dispose(bool disposing)
15. {
16. if (disposing && (components != null))
17. {
18. components.Dispose();
19. }
20. base.Dispose(disposing);
21. }
22. #region 组件设计器生成的代码
23. /// <summary>
24. /// 设计器支持所需的方法 – 不要
25. /// 使用代码编辑器修改此方法的内容。
26. /// </summary>
27. private void InitializeComponent()
28. {
29. this.button1 = new System.Windows.Forms.Button();
30. this.textBox1 = new System.Windows.Forms.TextBox();
31. this.listBox1 = new System.Windows.Forms.ListBox();
32. this.vScrollBar1 = new System.Windows.Forms.VScrollBar();
33. this.SuspendLayout();
34. //
35. // button1
36. //
37. this.button1.Location = new System.Drawing.Point(85, 0);
38. this.button1.Name = “button1”;
39. this.button1.Size = new System.Drawing.Size(65, 44);
40. this.button1.TabIndex = 0;
41. this.button1.Text = “▼”;
42. this.button1.UseVisualStyleBackColor = true;
43. this.button1.Click += new System.EventHandler(this.button1_Click);
44. //
45. // textBox1
46. //
47. this.textBox1.Font = new System.Drawing.Font(“宋体”, 24F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(134)));
48. this.textBox1.Location = new System.Drawing.Point(0, 0);
49. this.textBox1.Name = “textBox1”;
50. this.textBox1.Size = new System.Drawing.Size(88, 44);
51. this.textBox1.TabIndex = 1;
52. //
53. // listBox1
54. //
55. this.listBox1.Font = new System.Drawing.Font(“宋体”, 24F, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, ((byte)(134)));
56. this.listBox1.FormattingEnabled = true;
57. this.listBox1.ItemHeight = 33;
58. this.listBox1.Items.AddRange(new object[] {
59. “0”,
60. “1”,
61. “2”,
62. “3”,
63. “4”,
64. “5”,
65. “6”,
66. “7”,
67. “8”,
68. “9”});
69. this.listBox1.Location = new System.Drawing.Point(0, 44);
70. this.listBox1.Name = “listBox1”;
71. this.listBox1.Size = new System.Drawing.Size(148, 103);
72. this.listBox1.TabIndex = 2;
73. this.listBox1.SelectedIndexChanged += new System.EventHandler(this.listBox1_SelectedIndexChanged);
74. //
75. // vScrollBar1
76. //
77. this.vScrollBar1.Location = new System.Drawing.Point(85, 44);
78. this.vScrollBar1.Name = “vScrollBar1”;
79. this.vScrollBar1.Size = new System.Drawing.Size(63, 103);
80. this.vScrollBar1.TabIndex = 3;
81. //
82. // UserControl1
83. //
84. this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 12F);
85. this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
86. this.Controls.Add(this.vScrollBar1);
87. this.Controls.Add(this.listBox1);
88. this.Controls.Add(this.textBox1);
89. this.Controls.Add(this.button1);
90. this.Name = “UserControl1”;
91. this.Size = new System.Drawing.Size(149, 148);
92. this.ResumeLayout(false);
93. this.PerformLayout();
94. }
95. #endregion
96. private System.Windows.Forms.Button button1;
97. private System.Windows.Forms.TextBox textBox1;
98. private System.Windows.Forms.ListBox listBox1;
99. private System.Windows.Forms.VScrollBar vScrollBar1;
100. }
101. }