我們先實現單個按鈕，為了復用，不管單選還是復選按鈕都是使用同一個類來實現，為了區別單選還是復選，我們用一個自定義枚舉類型 CheckButtonStyle屬性style來區別，當其值設置為CheckButtonStyleDefault或CheckButtonStyleBox時，為復選按鈕：

當其值設為 CheckButtonStyleRadio時，為單選按鈕：

當按鈕在選中／反選狀態間切換時 ,文字左邊的圖片自動轉換。

整個控件是由一個 ImageView、一個Label、一個BOOL變量及其他變量組成，.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 ; // 勾選／反選時的圖片文件名

}

@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

具體實現如下：

#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 ]; // 默認風格為方框（多選）樣式

//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類很簡單，構造、設置標簽文本等屬性，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、單選按鈕組的實現

復選按鈕無所謂“組”的概念，單選按鈕則不同。在同一個組中，單選按鈕只允許同時選擇一個按鈕，不能選多個，因此我們要實現一個單選按鈕組的類：

#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 ) {

// 實現單選

for ( CheckButton * each in children ){

if (each. checked ) {

[each setChecked : NO ];

}

}

[cb setChecked : YES ];

// 復制選擇的項

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

單選按鈕組在 ViewController中的使用：

-( id )initWithNibName:( NSString *)nibNameOrNil bundle:( NSBundle *)nibBundleOrNil{

if ( self =[ super initWithNibName :nibNameOrNil bundle :nibBundleOrNil]){

// 單選按鈕組

rg =[[ RadioGroup alloc ] init ];

// 第 1 個單選按鈕

CheckButton * cb=[[ CheckButton alloc ] initWithFrame : CGRectMake ( 20 , 60 , 260 , 32 )];

// 把單選按鈕加入按鈕組

[ rg add :cb];

cb. label . text = @"★" ;

cb. value =[[ NSNumber alloc ] initWithInt : 1 ];

// 把按鈕設置為單選按鈕樣式

cb. style = CheckButtonStyleRadio ;

// 加入視圖

[ self . view addSubview :cb];

[cb release ]; //add 后，會自動持有，可以釋放

// 第 2 個單選按鈕

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 個單選按鈕

cb=[[ CheckButton alloc ] initWithFrame : CGRectMake ( 20 , 140 , 260 , 32 )];

// 各種屬性必須在 [rg addv] 之前設置，否則 text 和 value 不會被 populate

cb. checked = YES ;

cb. label . text = @"★★★" ;

cb. value =[[ NSNumber alloc ] initWithInt : 3 ];

cb. style = CheckButtonStyleRadio ;

[ self . view addSubview :cb];

[ rg add :cb]; // 屬性設置完之后再 add

[cb release ];

// 第 4 個單選按鈕

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 個單選按鈕

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 ;

}

運行效果：

自定義控件復選框和單選框的實現