[. Net custom control] ComboBox control rewriting-comboboxex

ComboBox extension, added the read-only value attribute, and selectedbyvalue and selectedbytext two methods

Method or attribute	Introduction
Text	Original control Property
Value	It is equivalent to selectedvalue in the ComboBox binding status or text in the non-binding status.
Selectedbyvalue (Object OBJ)	The value is selected based on valuemember when binding status, and the value is selected based on selecteditem when not binding status. Exact search
Selectedbytext (Object OBJ)	The options are displaymember-based and selecteditem-based. Exact search

 

Example:

Comboboxex1.text
Comboboxex1.value

Comboboxex1.selectedbyvalue ("2 ");
Comboboxex1.selectedbytext ("name3 ");

ControlsCode:

View plaincopy to clipboardprint?

2. Using system;
4. Using system. Windows. forms;
6. // Web: http://www.yongfa365.com/
8. Namespace yongfa365.controls. comboboxex
10. {
12. Public partial class comboboxex: ComboBox
14. {
16. Public comboboxex ()
18. {
20. This. dropdownstyle = comboboxstyle. dropdownlist;
22. }
26. Public void selectedbyvalue (Object OBJ)
28. {
30. If (this. datasource = NULL)
32. {
34. // When not bound
36. This. selecteditem = OBJ;
38. }
40. Else
42. {
44. Object prevalue = This. selectedvalue;
46. // Search directly when binding
48. This. selectedvalue = OBJ;
50. If (this. selectedvalue = NULL)
52. {
54. // Cannot be found to keep the original control value unchanged
56. This. selectedvalue = prevalue;
58. }
60. }
62. }
66. Public void selectedbytext (Object OBJ)
68. {
70. If (this. datasource = NULL)
72. {
74. // When not bound
76. This. selecteditem = OBJ;
78. }
80. Else
82. {
84. // When binding
86. This. Text = obj. tostring ();
88. }
90. }
94. Public String Value
96. {
98. Get
100. {
102. If (this. datasource = NULL)
104. {
106. // If it is not bound, text is returned.
108. Return this. text;
110. }
112. Else
114. {
116. // Return selectedvalue when binding
118. Return this. selectedvalue. tostring ();
120. }
122. }
124. }
126. }
128. }

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) {// This. selecteditem = OBJ;} else {object prevalue = This. selectedvalue; // you can directly find this when binding. selectedvalue = OBJ; If (this. selectedvalue = NULL) {// The original control value remains unchanged. selectedvalue = prevalue; }}} public void selectedbytext (Object OBJ) {If (this. datasource = NULL) {// This. selecteditem = OBJ;} else {// This. TEXT = obj. tostring () ;}} public string value {get {If (this. datasource = NULL) {// return text return this if it is not bound. text;} else {// return selectedvalue return this when binding. selectedvalue. tostring ();}}}}}

: Comboboxex.rar