（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。

开源地址：

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目录

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

  1 // 版权所有  黄正辉  交流群：568015492   qq：623128629
  2 // 文件名称：textboxex.cs
  3 // 创建日期：2019-08-15 16:03:44
  4 // 功能描述：textbox
  5 // 项目地址：https://gitee.com/kwwwvagaa/net_winform_custom_control
  6 using system;
  7 using system.collections.generic;
  8 using system.componentmodel;
  9 using system.diagnostics;
 10 using system.drawing;
 11 using system.linq;
 12 using system.text;
 13 using system.windows.forms;
 14 
 15 namespace hzh_controls.controls
 16 {
 17     public partial class textboxex : textbox
 18     {
 19         private bool blnfocus = false;
 20 
 21         private string _prompttext = string.empty;
 22 
 23         private font _promptfont = new font("微软雅黑", 15f, fontstyle.regular, graphicsunit.pixel);
 24 
 25         private color _promptcolor = color.gray;
 26 
 27         private rectangle _myrectangle = rectangle.fromltrb(1, 3, 1000, 3);
 28 
 29         private textinputtype _inputtype = textinputtype.notcontrol;
 30 
 31         private string _regexpattern = "";
 32 
 33         private string m_stroldvalue = string.empty;
 34 
 35         private decimal _maxvalue = 1000000m;
 36 
 37         private decimal _minvalue = -1000000m;
 38 
 39         private int _declength = 2;
 40 
 41         /// <summary>
 42         /// 水印文字
 43         /// </summary>
 44         [description("水印文字"), category("自定义")]
 45         public string prompttext
 46         {
 47             get
 48             {
 49                 return this._prompttext;
 50             }
 51             set
 52             {
 53                 this._prompttext = value;
 54                 this.onpaint(null);
 55             }
 56         }
 57 
 58         [description("水印字体"), category("自定义")]
 59         public font promptfont
 60         {
 61             get
 62             {
 63                 return this._promptfont;
 64             }
 65             set
 66             {
 67                 this._promptfont = value;
 68             }
 69         }
 70 
 71         [description("水印颜色"), category("自定义")]
 72         public color promptcolor
 73         {
 74             get
 75             {
 76                 return this._promptcolor;
 77             }
 78             set
 79             {
 80                 this._promptcolor = value;
 81             }
 82         }
 83 
 84         public rectangle myrectangle
 85         {
 86             get;
 87             set;
 88         }
 89 
 90         public string oldtext
 91         {
 92             get;
 93             set;
 94         }
 95 
 96         [description("获取或设置一个值，该值指示文本框中的文本输入类型。")]
 97         public textinputtype inputtype
 98         {
 99             get
100             {
101                 return this._inputtype;
102             }
103             set
104             {
105                 this._inputtype = value;
106                 if (value != textinputtype.notcontrol)
107                 {
108                     textchanged -= new eventhandler(this.textboxex_textchanged);
109                     textchanged += new eventhandler(this.textboxex_textchanged);
110                 }
111                 else
112                 {
113                     textchanged -= new eventhandler(this.textboxex_textchanged);
114                 }
115             }
116         }
117         /// <summary>
118         /// 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。
119         /// </summary>
120         [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。")]
121         public string regexpattern
122         {
123             get
124             {
125                 return this._regexpattern;
126             }
127             set
128             {
129                 this._regexpattern = value;
130             }
131         }
132         /// <summary>
133         /// 当inputtype为数字类型时，能输入的最大值
134         /// </summary>
135         [description("当inputtype为数字类型时，能输入的最大值。")]
136         public decimal maxvalue
137         {
138             get
139             {
140                 return this._maxvalue;
141             }
142             set
143             {
144                 this._maxvalue = value;
145             }
146         }
147         /// <summary>
148         /// 当inputtype为数字类型时，能输入的最小值
149         /// </summary>
150         [description("当inputtype为数字类型时，能输入的最小值。")]
151         public decimal minvalue
152         {
153             get
154             {
155                 return this._minvalue;
156             }
157             set
158             {
159                 this._minvalue = value;
160             }
161         }
162         /// <summary>
163         /// 当inputtype为数字类型时，能输入的最小值
164         /// </summary>
165         [description("当inputtype为数字类型时，小数位数。")]
166         public int declength
167         {
168             get
169             {
170                 return this._declength;
171             }
172             set
173             {
174                 this._declength = value;
175             }
176         }
177 
178         public textboxex()
179         {
180             this.initializecomponent();
181             base.gotfocus += new eventhandler(this.textboxex_gotfocus);
182             base.mouseup += new mouseeventhandler(this.textboxex_mouseup);
183             base.keypress += textboxex_keypress;
184         }
185 
186         void textboxex_keypress(object sender, keypresseventargs e)
187         {
188             //以下代码  取消按下回车或esc的“叮”声
189             if (e.keychar == system.convert.tochar(13) || e.keychar == system.convert.tochar(27))
190             {
191                 e.handled = true;
192             }
193         }
194 
195         private void textboxex_mouseup(object sender, mouseeventargs e)
196         {
197             if (this.blnfocus)
198             {
199                 base.selectall();
200                 this.blnfocus = false;
201             }
202         }
203 
204         private void textboxex_gotfocus(object sender, eventargs e)
205         {
206             this.blnfocus = true;
207             base.selectall();
208         }
209 
210         private void textboxex_textchanged(object sender, eventargs e)
211         {
212             if (this.text == "")
213             {
214                 this.m_stroldvalue = this.text;
215             }
216             else if (this.m_stroldvalue != this.text)
217             {
218                 if (!controlhelper.checkinputtype(this.text, this._inputtype, this._maxvalue, this._minvalue, this._declength, this._regexpattern))
219                 {
220                     int num = base.selectionstart;
221                     if (this.m_stroldvalue.length < this.text.length)
222                     {
223                         num--;
224                     }
225                     else
226                     {
227                         num++;
228                     }
229                     base.textchanged -= new eventhandler(this.textboxex_textchanged);
230                     this.text = this.m_stroldvalue;
231                     base.textchanged += new eventhandler(this.textboxex_textchanged);
232                     if (num < 0)
233                     {
234                         num = 0;
235                     }
236                     base.selectionstart = num;
237                 }
238                 else
239                 {
240                     this.m_stroldvalue = this.text;
241                 }
242             }
243         }
244 
245         protected override void onpaint(painteventargs e)
246         {
247             base.onpaint(e);
248             if (string.isnullorempty(this.text) && !string.isnullorempty(this._prompttext))
249             {
250                 if (e == null)
251                 {
252                     using (graphics graphics = graphics.fromhwnd(base.handle))
253                     {
254                         if (this.text.length == 0 && !string.isnullorempty(this.prompttext))
255                         {
256                             textformatflags textformatflags = textformatflags.endellipsis | textformatflags.verticalcenter;
257                             if (this.righttoleft == righttoleft.yes)
258                             {
259                                 textformatflags |= (textformatflags.right | textformatflags.righttoleft);
260                             }
261                             textrenderer.drawtext(graphics, this.prompttext, this._promptfont, base.clientrectangle, this._promptcolor, textformatflags);
262                         }
263                     }
264                 }
265             }
266         }
267 
268         protected override void wndproc(ref message m)
269         {
270             base.wndproc(ref m);
271             if (m.msg == 15 || m.msg == 7 || m.msg == 8)
272             {
273                 this.onpaint(null);
274             }
275         }
276 
277         protected override void ontextchanged(eventargs e)
278         {
279             base.ontextchanged(e);
280             base.invalidate();
281         }
282     }
283 }

用处及效果

用处：需要控制输入，需要显示水印

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