我们先实现单个按钮，为了复用，不管单选还是复选按钮都是使用同一个类来实现，为了区别单选还是复选，我们用一个自定义枚举类型CheckButtonStyle属性style来区别，当其值设置为CheckButtonStyleDefault或CheckButtonStyleBox时，为复选按钮：
当其值设为CheckButtonStyleRadio时，为单选按钮：
当按钮在选中／反选状态间切换时,文字左边的图片自动转换。
整个控件是由一个ImageView、一个Label、一个BOOL变量及其他变量组成，.h文件如下：
typedef enum {
CheckButtonStyleDefault = 0 ,
CheckButtonStyleBox = 1 ,
CheckButtonStyleRadio = 2
} CheckButtonStyle;
#import <Foundation/Foundation.h>
@interface CheckButton : UIControl {
//UIControl* control;
UILabel * label ;
UIImageView * icon ;
BOOL checked ;
id value , delegate ;
CheckButtonStyle style ;
NSString * checkname ,* uncheckname ; // 勾选／反选时的图片文件名
}
@property ( retain , nonatomic ) id value,delegate;
@property ( retain , nonatomic )UILabel* label;
@property ( retain , nonatomic )UIImageView* icon;
@property ( assign )CheckButtonStyle style;
-( CheckButtonStyle )style;
-( void )setStyle:( CheckButtonStyle )st;
-( BOOL )isChecked;
-( void )setChecked:( BOOL )b;
@end
具体实现如下：
#import "CheckButton.h"
@implementation CheckButton
@synthesize label,icon,value,delegate;
-( id )initWithFrame:( CGRect ) frame
{
if ( self =[ super initWithFrame : frame ]) {
icon =[[ UIImageView alloc ] initWithFrame :
CGRectMake ( 10 , 0 , frame . size . height , frame . size . height )];
[ self setStyle : CheckButtonStyleDefault ]; // 默认风格为方框（多选）样式
//self.backgroundColor=[UIColor grayColor];
[ self addSubview : icon ];
label =[[ UILabel alloc ] initWithFrame : CGRectMake ( icon . frame . size . width + 24 , 0 ,
frame . size . width - icon . frame . size . width - 24 ,
frame . size . height )];
label . backgroundColor =[ UIColor clearColor ];
label . font =[ UIFont fontWithName : @"Arial" size : 20 ];
label . textColor =[ UIColor
colorWithRed : 0xf9 / 255.0
green : 0xd8 / 255.0
blue : 0x67 / 255.0
alpha : 1 ];
label . textAlignment = UITextAlignmentLeft ;
[ self addSubview : label ];
[ self addTarget : self action : @selector ( clicked ) forControlEvents : UIControlEventTouchUpInside ];
}
return self ;
}
-( CheckButtonStyle )style{
return style ;
}
-( void )setStyle:( CheckButtonStyle )st{
style =st;
switch ( style ) {
case CheckButtonStyleDefault :
case CheckButtonStyleBox :
checkname = @"checked.png" ;
uncheckname = @"unchecked.png" ;
break ;
case CheckButtonStyleRadio :
checkname = @"radio.png" ;
uncheckname = @"unradio.png" ;
break ;
default :
break ;
}
[ self setChecked : checked ];
}
-( BOOL )isChecked{
return checked ;
}
-( void )setChecked:( BOOL )b{
if (b!= checked ){
checked =b;
}
if ( checked ) {
[ icon setImage :[ UIImage imageNamed : checkname ]];
} else {
[ icon setImage :[ UIImage imageNamed : uncheckname ]];
}
}
-( void )clicked{
[ self setChecked :! checked ];
if ( delegate != nil ) {
SEL sel= NSSelectorFromString ( @"checkButtonClicked" );
if ([ delegate respondsToSelector :sel]){
[ delegate performSelector :sel];
}
}
}
-( void )dealloc{
value = nil ; delegate = nil ;
[ label release ];
[ icon release ];
[ super dealloc ];
}
@end
使用CheckButton类很简单，构造、设置标签文本等属性，然后addSubview：
CheckButton * cb=[[ CheckButton a lloc ] initWithFrame : CGRectMake ( 20 , 60 , 260 , 32 )];
cb. label . text = @"checkbutton1" ;
cb. value =[[ NSNumber alloc ] initWithInt : 18 ];
cb. style = CheckButtonStyleDefault ;
[ self . view addSubview :cb];
二、单选按钮组的实现
复选按钮无所谓“组”的概念，单选按钮则不同。在同一个组中，单选按钮只允许同时选择一个按钮，不能选多个，因此我们要实现一个单选按钮组的类：
#import <Foundation/Foundation.h>
#import "CheckButton.h"
@interface RadioGroup : NSObject {
NSMutableArray * children ;
NSString * text ;
id value ;
}
@property ( readonly )NSString* text;
@property ( readonly ) id value;
-( void )add:( CheckButton *)cb;
-( void )checkButtonClicked:( id )sender;
@end
#import "RadioGroup.h"
@implementation RadioGroup
@synthesize text,value;
-( id )init{
if ( self =[ super init ]){
children =[[ NSMutableArray alloc ] init ];
}
return self ;
}
-( void )add:( CheckButton *)cb{
cb. delegate = self ;
if (cb. checked ) {
text =cb. label . text ;
value =cb. value ;
}
[ children addObject :cb];
}
-( void )checkButtonClicked:( id )sender{
CheckButton * cb=( CheckButton *)sender;
if (!cb. checked ) {
// 实现单选
for ( CheckButton * each in children ){
if (each. checked ) {
[each setChecked : NO ];
}
}
[cb setChecked : YES ];
// 复制选择的项
text =cb. label . text ;
value =cb. value ;
}
NSLog ( @"text:%@,value:%d" , text ,[( NSNumber *) value intValue ]);
}
-( void )dealloc{
[ text release ];
value = nil ;
[ children release ];
[ super dealloc ];
}
@end
单选按钮组在ViewController中的使用：
-( id )initWithNibName:( NSString *)nibNameOrNil bundle:( NSBundle *)nibBundleOrNil{
if ( self =[ super initWithNibName :nibNameOrNil bundle :nibBundleOrNil]){
// 单选按钮组
rg =[[ RadioGroup alloc ] init ];
// 第 1 个单选按钮
CheckButton * cb=[[ CheckButton alloc ] initWithFrame : CGRectMake ( 20 , 60 , 260 , 32 )];
// 把单选按钮加入按钮组
[ rg add :cb];
cb. label . text = @"★" ;
cb. value =[[ NSNumber alloc ] initWithInt : 1 ];
// 把按钮设置为单选按钮样式
cb. style = CheckButtonStyleRadio ;
// 加入视图
[ self . view addSubview :cb];
[cb release ]; //add 后，会自动持有，可以释放
// 第 2 个单选按钮
cb=[[ CheckButton alloc ] initWithFrame : CGRectMake ( 20 , 100 , 260 , 32 )];
[ rg add :cb];
cb. label . text = @"★★" ;
cb. value =[[ NSNumber alloc ] initWithInt : 2 ];
cb. style = CheckButtonStyleRadio ;
[ self . view addSubview :cb];
[cb release ];
// 第 3 个单选按钮
cb=[[ CheckButton alloc ] initWithFrame : CGRectMake ( 20 , 140 , 260 , 32 )];
// 各种属性必须在 [rg addv] 之前设置，否则 text 和 value 不会被 populate
cb. checked = YES ;
cb. label . text = @"★★★" ;
cb. value =[[ NSNumber alloc ] initWithInt : 3 ];
cb. style = CheckButtonStyleRadio ;
[ self . view addSubview :cb];
[ rg add :cb]; // 属性设置完之后再 add
[cb release ];
// 第 4 个单选按钮
cb=[[ CheckButton alloc ] initWithFrame : CGRectMake ( 20 , 180 , 260 , 32 )];
[ rg add :cb];
cb. label . text = @"★★★★" ;
cb. value =[[ NSNumber alloc ] initWithInt : 4 ];
cb. style = CheckButtonStyleRadio ;
[ self . view addSubview :cb];
[cb release ];
// 第 5 个单选按钮
cb=[[ CheckButton alloc ] initWithFrame : CGRectMake ( 20 , 220 , 260 , 32 )];
[ rg add :cb];
cb. label . text = @"★★★★★" ;
cb. value =[[ NSNumber alloc ] initWithInt : 5 ];
cb. style = CheckButtonStyleRadio ;
[ self . view addSubview :cb];
[cb release ];
}
return self ;
}
运行效果：
