[.net自定义控件]ComboBox控件重写 之ComboBoxEx

ComboBox的扩展，添加了只读Value属性，和SelectedByValue及SelectedByText两个方法

方法或属性	介绍
Text	原控件属性
Value	等价于ComboBox绑定状态的SelectedValue,或非绑定状态的：Text
SelectedByValue(object obj)	绑定状态时根据ValueMember选择，非绑定状态时根据SelectedItem选择。精确查找
SelectedByText(object obj)	绑定状态时根据DisplayMember选择，非绑定状态时根据SelectedItem选择。精确查找

使用示例：

comboBoxEx1.Text
comboBoxEx1.Value

comboBoxEx1.SelectedByValue("2");
comboBoxEx1.SelectedByText("Name3");

控件主要代码：

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1. using System;  
2. using System.Windows.Forms;  
3. //web:http://www.yongfa365.com/  
4. namespace YongFa365.Controls.ComboBoxEx  
5. {  
6.     public partial class ComboBoxEx : ComboBox  
7.     {  
8.         public ComboBoxEx()  
9.         {  
10.             this.DropDownStyle = ComboBoxStyle.DropDownList;  
11.         }  
12.   
13.         public void SelectedByValue(object obj)  
14.         {  
15.             if (this.DataSource == null)  
16.             {  
17.                 //非绑定时  
18.                 this.SelectedItem = obj;  
19.             }  
20.             else  
21.             {  
22.                 object preValue = this.SelectedValue;  
23.                 //绑定时直接查找  
24.                 this.SelectedValue = obj;  
25.                 if (this.SelectedValue == null)  
26.                 {  
27.                     //查不到保持原控件值不变  
28.                     this.SelectedValue = preValue;  
29.                 }  
30.             }  
31.         }  
32.   
33.         public void SelectedByText(object obj)  
34.         {  
35.             if (this.DataSource == null)  
36.             {  
37.                 //非绑定时  
38.                 this.SelectedItem = obj;  
39.             }  
40.             else  
41.             {  
42.                 //绑定时  
43.                 this.Text = obj.ToString();  
44.             }  
45.         }  
46.   
47.         public string Value  
48.         {  
49.             get  
50.             {  
51.                 if (this.DataSource == null)  
52.                 {  
53.                     //非绑定时返回Text  
54.                     return this.Text;  
55.                 }  
56.                 else  
57.                 {  
58.                     //绑定时返回SelectedValue  
59.                     return this.SelectedValue.ToString();  
60.                 }  
61.             }  
62.         }  
63.     }  
64. }  

using System; using System.Windows.Forms; //web:http://www.yongfa365.com/ namespace YongFa365.Controls.ComboBoxEx {     public partial class ComboBoxEx : ComboBox     {         public ComboBoxEx()         {             this.DropDownStyle = ComboBoxStyle.DropDownList;         }          public void SelectedByValue(object obj)         {             if (this.DataSource == null)             {                 //非绑定时                 this.SelectedItem = obj;             }             else             {                 object preValue = this.SelectedValue;                 //绑定时直接查找                 this.SelectedValue = obj;                 if (this.SelectedValue == null)                 {                     //查不到保持原控件值不变                     this.SelectedValue = preValue;                 }             }         }          public void SelectedByText(object obj)         {             if (this.DataSource == null)             {                 //非绑定时                 this.SelectedItem = obj;             }             else             {                 //绑定时                 this.Text = obj.ToString();             }         }          public string Value         {             get             {                 if (this.DataSource == null)                 {                     //非绑定时返回Text                     return this.Text;                 }                 else                 {                     //绑定时返回SelectedValue                     return this.SelectedValue.ToString();                 }             }         }     } } 

下载地址：ComboBoxEx.rar