NSInvocation调用

CurrentDate.h

   
     

    
      #import 
    
      <
    
      Foundation
    
      /
    
      Foundation.h
    
      >
    
      


@interface CurrentDate : NSObject {
 
}

    
      -
    
       (NSString 
    
      *
    
      ) stringForDate: (NSDate 
    
      *
    
      )date 
 usingFormatter: (NSDateFormatter 
    
      *
    
      )formatter;

@end
   
     

CurrentDate.m

   
     

    
      #import 
    
      "
    
      CurrentDate.h
    
      "
    
      


@implementation CurrentDate


    
      -
    
       (NSString 
    
      *
    
      ) stringForDate: (NSDate 
    
      *
    
      )date 
 usingFormatter: (NSDateFormatter 
    
      *
    
      )formatter
{
 
    
      return
    
       [formatter stringFromDate: date];
}

@end
   
     

main.m

   
     

    
      #import 
    
      <
    
      Foundation
    
      /
    
      Foundation.h
    
      >
    
      
#import 
    
      "
    
      CurrentDate.h
    
      "
    
      


    
      //
    
      参考：
    
      http://theocacao.com/document.page/264
    
      

    
      int
    
       main (
    
      int
    
       argc, 
    
      const
    
       
    
      char
    
       
    
      *
    
       argv[])
{

 NSAutoreleasePool 
    
      *
    
       pool 
    
      =
    
       [[NSAutoreleasePool alloc] init];

 
    
      //
    
      原始调用
    
      

    
       NSDateFormatter 
    
      *
    
       dateFormat 
    
      =
    
       [[NSDateFormatter alloc] 
 initWithDateFormat:
    
      @"
    
      %b %d %Y
    
      "
    
       
 allowNaturalLanguage: NO];
 CurrentDate 
    
      *
    
       currentDateClassObject 
    
      =
    
       [[CurrentDate alloc] init];
 NSString 
    
      *
    
       currentDate 
    
      =
    
       [currentDateClassObject 
 stringForDate: [NSDate date] 
 usingFormatter: dateFormat];
 NSLog(
    
      @"
    
      currentDate: %@
    
      "
    
      , currentDate);
 
 
 
    
      //
    
      NSInvocation调用
    
      

    
       SEL mySelector 
    
      =
    
       @selector(stringForDate:usingFormatter:);
 NSMethodSignature 
    
      *
    
       sig 
    
      =
    
       [[currentDateClassObject 
    
      class
    
      ] 
 instanceMethodSignatureForSelector: mySelector];
 
 NSInvocation 
    
      *
    
       myInvocation 
    
      =
    
       [NSInvocation invocationWithMethodSignature: sig];
 [myInvocation setTarget: currentDateClassObject];
 [myInvocation setSelector: mySelector];
 
 NSDate 
    
      *
    
       myDate 
    
      =
    
       [NSDate date];
 [myInvocation setArgument: 
    
      &
    
      myDate atIndex: 
    
      2
    
      ];
 
 NSDateFormatter 
    
      *
    
       dateFormatter 
    
      =
    
       [[NSDateFormatter alloc] init];
 [dateFormatter setDateStyle: NSDateFormatterMediumStyle]; 
 [myInvocation setArgument: 
    
      &
    
      dateFormatter atIndex: 
    
      3
    
      ];
 
 NSString 
    
      *
    
       result 
    
      =
    
       nil; 
 [myInvocation retainArguments]; 
 [myInvocation invoke];
 [myInvocation getReturnValue: 
    
      &
    
      result];
 NSLog(
    
      @"
    
      The result is: %@
    
      "
    
      , result);
 

 [pool drain];
 
    
      return
    
       
    
      0
    
      ;
}