error of "_OBJC_CLASS_$_EXFJpeg"

What steps will reproduce the problem?
1. I add framework and *.h from Release-simulator-iphonesimulator 
2. then I only want to test the simply demo, codes are:

exifTestViewController.h

#import <UIKit/UIKit.h>
#import "EXF.h"
@interface exifTestViewController : UIViewController {
    //lsy 110929 00:00am
    UIImage *exifImg_lsy;
    UIImageView *imgDisplayImgView_lsy;
    NSData *imageData_lsy;
}

@property (nonatomic,retain) UIImage *exifImg_lsy;
@property (nonatomic,retain) IBOutlet UIImageView *imgDisplayImgView_lsy;
@property (nonatomic ,retain ) NSData *imageData_lsy;

@end

exifTestViewController.m

#import "exifTestViewController.h"

@implementation exifTestViewController
//lsy 110929 00:00am
@synthesize exifImg_lsy;
@synthesize imgDisplayImgView_lsy;
@synthesize imageData_lsy;
- (void)viewDidLoad {

    //lsy 110929 00:00am
    exifImg_lsy = [UIImage imageWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"test" ofType:@"jpg"]];
    [imgDisplayImgView_lsy setImage:exifImg_lsy];
    NSData * uiJpeg = UIImageJPEGRepresentation (exifImg_lsy, 1.0 );
    EXFJpeg* jpegScanner = [[EXFJpeg alloc] init];
    [jpegScanner scanImageData: uiJpeg];
    //self.imageData_lsy = jpegScanner;
    NSLog(@"picture length:::%d",jpegScanner.exifMetaData.height);  
    [jpegScanner release];
    [super viewDidLoad];
}
3.then error disappeared:
Ld build/Debug-iphonesimulator/exifTest.app/exifTest normal i386
cd /Users/baizhitebaizhite/Desktop/LSY/exifTest
setenv MACOSX_DEPLOYMENT_TARGET 10.6
setenv PATH 
"/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin:/Developer/usr/
bin:/usr/bin:/bin:/usr/sbin:/sbin"
/Developer/Platforms/iPhoneSimulator.platform/Developer/usr/bin/gcc-4.2 -arch 
i386 -isysroot 
/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator4.2.
sdk -L/Users/baizhitebaizhite/Desktop/LSY/exifTest/build/Debug-iphonesimulator 
-L/Users/baizhitebaizhite/Desktop/LSY/exifTest 
-F/Users/baizhitebaizhite/Desktop/LSY/exifTest/build/Debug-iphonesimulator 
-filelist 
/Users/baizhitebaizhite/Desktop/LSY/exifTest/build/exifTest.build/Debug-iphonesi
mulator/exifTest.build/Objects-normal/i386/exifTest.LinkFileList 
-mmacosx-version-min=10.6 -Xlinker -objc_abi_version -Xlinker 2 -framework 
Foundation -framework UIKit -framework CoreGraphics -liphone-exif -o 
/Users/baizhitebaizhite/Desktop/LSY/exifTest/build/Debug-iphonesimulator/exifTes
t.app/exifTest

Undefined symbols:
  "_OBJC_CLASS_$_EXFJpeg", referenced from:
      objc-class-ref-to-EXFJpeg in exifTestViewController.o
ld: symbol(s) not found
collect2: ld returned 1 exit status

please help me...Thanks.... 

What is the expected output? What do you see instead?

What version of the product are you using? On what operating system?
iphone simulator 4.2

Please provide any additional information below.
Original issue reported on code.google.com by LSY...@gmail.com on 29 Sep 2011 at 1:47
Attachments:
0.png
1.png
nagyist / iphone-exif

error of "_OBJC_CLASS_$_EXFJpeg" #12
