（二十八）c#Winform自定义控件-文本框（一）
·
前提
入行已经7,8年了，一直想做一套漂亮点的自定义控件，于是就有了本系列文章。
官网：https://www.hzhcontrols.cn
GitHub：https://github.com/kwwwvagaa/NetWinformControl
如果觉得写的还行，请点个 star 支持一下吧
欢迎前来交流探讨： 企鹅群568015492 
目录
c#Winform自定义控件-目录_c#winform自定义控件-有图标的按钮-CSDN博客
准备工作
终于到文本框了，文本框将包含原文本框扩展，透明文本框，数字输入文本框，带边框文本框
本文将讲解原文本框扩展，主要增加水印和输入控制
开始
添加一个组件，命名TextBoxEx，继承TextBox
属性
1 private bool blnFocus = false;
2
3 private string _promptText = string.Empty;
4
5 private Font _promptFont = new Font("微软雅黑", 15f, FontStyle.Regular, GraphicsUnit.Pixel);
6
7 private Color _promptColor = Color.Gray;
8
9 private Rectangle _myRectangle = Rectangle.FromLTRB(1, 3, 1000, 3);
10
11 private TextInputType _inputType = TextInputType.NotControl;
12
13 private string _regexPattern = "";
14
15 private string m_strOldValue = string.Empty;
16
17 private decimal _maxValue = 1000000m;
18
19 private decimal _minValue = -1000000m;
20
21 private int _decLength = 2;
22
23 /// <summary>
24 /// 水印文字
25 /// </summary>
26 [Description("水印文字"), Category("自定义")]
27 public string PromptText
28 {
29 get
30 {
31 return this._promptText;
32 }
33 set
34 {
35 this._promptText = value;
36 this.OnPaint(null);
37 }
38 }
39
40 [Description("水印字体"), Category("自定义")]
41 public Font PromptFont
42 {
43 get
44 {
45 return this._promptFont;
46 }
47 set
48 {
49 this._promptFont = value;
50 }
51 }
52
53 [Description("水印颜色"), Category("自定义")]
54 public Color PromptColor
55 {
56 get
57 {
58 return this._promptColor;
59 }
60 set
61 {
62 this._promptColor = value;
63 }
64 }
65
66 public Rectangle MyRectangle
67 {
68 get;
69 set;
70 }
71
72 public string OldText
73 {
74 get;
75 set;
76 }
77
78 [Description("获取或设置一个值，该值指示文本框中的文本输入类型。")]
79 public TextInputType InputType
80 {
81 get
82 {
83 return this._inputType;
84 }
85 set
86 {
87 this._inputType = value;
88 if (value != TextInputType.NotControl)
89 {
90 TextChanged -= new EventHandler(this.TextBoxEx_TextChanged);
91 TextChanged += new EventHandler(this.TextBoxEx_TextChanged);
92 }
93 else
94 {
95 TextChanged -= new EventHandler(this.TextBoxEx_TextChanged);
96 }
97 }
98 }
99 /// <summary>
100 /// 获取或设置一个值，该值指示当输入类型InputType=Regex时，使用的正则表达式。
101 /// </summary>
102 [Description("获取或设置一个值，该值指示当输入类型InputType=Regex时，使用的正则表达式。")]
103 public string RegexPattern
104 {
105 get
106 {
107 return this._regexPattern;
108 }
109 set
110 {
111 this._regexPattern = value;
112 }
113 }
114 /// <summary>
115 /// 当InputType为数字类型时，能输入的最大值
116 /// </summary>
117 [Description("当InputType为数字类型时，能输入的最大值。")]
118 public decimal MaxValue
119 {
120 get
121 {
122 return this._maxValue;
123 }
124 set
125 {
126 this._maxValue = value;
127 }
128 }
129 /// <summary>
130 /// 当InputType为数字类型时，能输入的最小值
131 /// </summary>
132 [Description("当InputType为数字类型时，能输入的最小值。")]
133 public decimal MinValue
134 {
135 get
136 {
137 return this._minValue;
138 }
139 set
140 {
141 this._minValue = value;
142 }
143 }
144 /// <summary>
145 /// 当InputType为数字类型时，能输入的最小值
146 /// </summary>
147 [Description("当InputType为数字类型时，小数位数。")]
148 public int DecLength
149 {
150 get
151 {
152 return this._decLength;
153 }
154 set
155 {
156 this._decLength = value;
157 }
158 }
一些事件
1 void TextBoxEx_KeyPress(object sender, KeyPressEventArgs e)
2 {
3 //以下代码 取消按下回车或esc的“叮”声
4 if (e.KeyChar == System.Convert.ToChar(13) || e.KeyChar == System.Convert.ToChar(27))
5 {
6 e.Handled = true;
7 }
8 }
9
10 private void TextBoxEx_MouseUp(object sender, MouseEventArgs e)
11 {
12 if (this.blnFocus)
13 {
14 base.SelectAll();
15 this.blnFocus = false;
16 }
17 }
18
19 private void TextBoxEx_GotFocus(object sender, EventArgs e)
20 {
21 this.blnFocus = true;
22 base.SelectAll();
23 }
24
25 private void TextBoxEx_TextChanged(object sender, EventArgs e)
26 {
27 if (this.Text == "")
28 {
29 this.m_strOldValue = this.Text;
30 }
31 else if (this.m_strOldValue != this.Text)
32 {
33 if (!ControlHelper.CheckInputType(this.Text, this._inputType, this._maxValue, this._minValue, this._decLength, this._regexPattern))
34 {
35 int num = base.SelectionStart;
36 if (this.m_strOldValue.Length < this.Text.Length)
37 {
38 num--;
39 }
40 else
41 {
42 num++;
43 }
44 base.TextChanged -= new EventHandler(this.TextBoxEx_TextChanged);
45 this.Text = this.m_strOldValue;
46 base.TextChanged += new EventHandler(this.TextBoxEx_TextChanged);
47 if (num < 0)
48 {
49 num = 0;
50 }
51 base.SelectionStart = num;
52 }
53 else
54 {
55 this.m_strOldValue = this.Text;
56 }
57 }
58 }
重绘
1 protected override void OnPaint(PaintEventArgs e)
2 {
3 base.OnPaint(e);
4 if (string.IsNullOrEmpty(this.Text) && !string.IsNullOrEmpty(this._promptText))
5 {
6 if (e == null)
7 {
8 using (Graphics graphics = Graphics.FromHwnd(base.Handle))
9 {
10 if (this.Text.Length == 0 && !string.IsNullOrEmpty(this.PromptText))
11 {
12 TextFormatFlags textFormatFlags = TextFormatFlags.EndEllipsis | TextFormatFlags.VerticalCenter;
13 if (this.RightToLeft == RightToLeft.Yes)
14 {
15 textFormatFlags |= (TextFormatFlags.Right | TextFormatFlags.RightToLeft);
16 }
17 TextRenderer.DrawText(graphics, this.PromptText, this._promptFont, base.ClientRectangle, this._promptColor, textFormatFlags);
18 }
19 }
20 }
21 }
22 }
下面是完整代码
// 版权所有 黄正辉 交流群：568015492 QQ：623128629
// 文件名称：TextBoxEx.cs
// 创建日期：2019-08-15 16:03:44
// 功能描述：TextBox
// 项目地址：https://gitee.com/kwwwvagaa/net_winform_custom_control
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Diagnostics;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
namespace HZH_Controls.Controls
{
public partial class TextBoxEx : TextBox
{
private bool blnFocus = false;
private string _promptText = string.Empty;
private Font _promptFont = new Font("微软雅黑", 15f, FontStyle.Regular, GraphicsUnit.Pixel);
private Color _promptColor = Color.Gray;
private Rectangle _myRectangle = Rectangle.FromLTRB(1, 3, 1000, 3);
private TextInputType _inputType = TextInputType.NotControl;
private string _regexPattern = "";
private string m_strOldValue = string.Empty;
private decimal _maxValue = 1000000m;
private decimal _minValue = -1000000m;
private int _decLength = 2;
/// <summary>
/// 水印文字
/// </summary>
[Description("水印文字"), Category("自定义")]
public string PromptText
{
get
{
return this._promptText;
}
set
{
this._promptText = value;
this.OnPaint(null);
}
}
[Description("水印字体"), Category("自定义")]
public Font PromptFont
{
get
{
return this._promptFont;
}
set
{
this._promptFont = value;
}
}
[Description("水印颜色"), Category("自定义")]
public Color PromptColor
{
get
{
return this._promptColor;
}
set
{
this._promptColor = value;
}
}
public Rectangle MyRectangle
{
get;
set;
}
public string OldText
{
get;
set;
}
[Description("获取或设置一个值，该值指示文本框中的文本输入类型。")]
public TextInputType InputType
{
get
{
return this._inputType;
}
set
{
this._inputType = value;
if (value != TextInputType.NotControl)
{
TextChanged -= new EventHandler(this.TextBoxEx_TextChanged);
TextChanged += new EventHandler(this.TextBoxEx_TextChanged);
}
else
{
TextChanged -= new EventHandler(this.TextBoxEx_TextChanged);
}
}
}
/// <summary>
/// 获取或设置一个值，该值指示当输入类型InputType=Regex时，使用的正则表达式。
/// </summary>
[Description("获取或设置一个值，该值指示当输入类型InputType=Regex时，使用的正则表达式。")]
public string RegexPattern
{
get
{
return this._regexPattern;
}
set
{
this._regexPattern = value;
}
}
/// <summary>
/// 当InputType为数字类型时，能输入的最大值
/// </summary>
[Description("当InputType为数字类型时，能输入的最大值。")]
public decimal MaxValue
{
get
{
return this._maxValue;
}
set
{
this._maxValue = value;
}
}
/// <summary>
/// 当InputType为数字类型时，能输入的最小值
/// </summary>
[Description("当InputType为数字类型时，能输入的最小值。")]
public decimal MinValue
{
get
{
return this._minValue;
}
set
{
this._minValue = value;
}
}
/// <summary>
/// 当InputType为数字类型时，能输入的最小值
/// </summary>
[Description("当InputType为数字类型时，小数位数。")]
public int DecLength
{
get
{
return this._decLength;
}
set
{
this._decLength = value;
}
}
public TextBoxEx()
{
this.InitializeComponent();
base.GotFocus += new EventHandler(this.TextBoxEx_GotFocus);
base.MouseUp += new MouseEventHandler(this.TextBoxEx_MouseUp);
base.KeyPress += TextBoxEx_KeyPress;
}
void TextBoxEx_KeyPress(object sender, KeyPressEventArgs e)
{
//以下代码 取消按下回车或esc的“叮”声
if (e.KeyChar == System.Convert.ToChar(13) || e.KeyChar == System.Convert.ToChar(27))
{
e.Handled = true;
}
}
private void TextBoxEx_MouseUp(object sender, MouseEventArgs e)
{
if (this.blnFocus)
{
base.SelectAll();
this.blnFocus = false;
}
}
private void TextBoxEx_GotFocus(object sender, EventArgs e)
{
this.blnFocus = true;
base.SelectAll();
}
private void TextBoxEx_TextChanged(object sender, EventArgs e)
{
if (this.Text == "")
{
this.m_strOldValue = this.Text;
}
else if (this.m_strOldValue != this.Text)
{
if (!ControlHelper.CheckInputType(this.Text, this._inputType, this._maxValue, this._minValue, this._decLength, this._regexPattern))
{
int num = base.SelectionStart;
if (this.m_strOldValue.Length < this.Text.Length)
{
num--;
}
else
{
num++;
}
base.TextChanged -= new EventHandler(this.TextBoxEx_TextChanged);
this.Text = this.m_strOldValue;
base.TextChanged += new EventHandler(this.TextBoxEx_TextChanged);
if (num < 0)
{
num = 0;
}
base.SelectionStart = num;
}
else
{
this.m_strOldValue = this.Text;
}
}
}
protected override void OnPaint(PaintEventArgs e)
{
base.OnPaint(e);
if (string.IsNullOrEmpty(this.Text) && !string.IsNullOrEmpty(this._promptText))
{
if (e == null)
{
using (Graphics graphics = Graphics.FromHwnd(base.Handle))
{
if (this.Text.Length == 0 && !string.IsNullOrEmpty(this.PromptText))
{
TextFormatFlags textFormatFlags = TextFormatFlags.EndEllipsis | TextFormatFlags.VerticalCenter;
if (this.RightToLeft == RightToLeft.Yes)
{
textFormatFlags |= (TextFormatFlags.Right | TextFormatFlags.RightToLeft);
}
TextRenderer.DrawText(graphics, this.PromptText, this._promptFont, base.ClientRectangle, this._promptColor, textFormatFlags);
}
}
}
}
}
protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
if (m.Msg == 15 || m.Msg == 7 || m.Msg == 8)
{
this.OnPaint(null);
}
}
protected override void OnTextChanged(EventArgs e)
{
base.OnTextChanged(e);
base.Invalidate();
}
}
}用处及效果
用处：需要控制输入，需要显示水印
最后的话
魔乐社区（Modelers.cn) 是一个中立、公益的人工智能社区，提供人工智能工具、模型、数据的托管、展示与应用协同服务，为人工智能开发及爱好者搭建开放的学习交流平台。社区通过理事会方式运作，由全产业链共同建设、共同运营、共同享有，推动国产AI生态繁荣发展。
更多推荐
0
0- 0
已为社区贡献16条内容
所有评论(0)