How to open epub file in iBooks using ANE(iOS) ?

hello,

I tried to open epub file in iBooks using Native Extensions.

But, AIR app has crashed when calling ANE method (following: OpenEpub).

Have problems with how to access the epub file?

Or another problem?

MacOS:10.6.8

Xcode:4.2

FlashBulder:4.6

FlexSDK:4.6.0(default bundle version)

TestDevice:1st iPad (OS 5.0.1)

iOSNativeCode(this code works on native iOS app):

#import <UIKit/UIKit.h>
FREObject OpenEpub(FREContext ctx, void* funcData, uint32_t argc, FREObject argv[]){
    id delegate = [[UIApplication sharedApplication] delegate]; 
    UIWindow* window = [delegate window];
    UIButton* uiBtn = [[[UIButton alloc] init] retain];
    [window addSubview:uiBtn];
    NSString *fileToOpen = [[NSBundle mainBundle] pathForResource:@"test" ofType:@"epub"];
    NSURL *url = [NSURL fileURLWithPath:fileToOpen];
    UIDocumentInteractionController *docController = [UIDocumentInteractionController interactionControllerWithURL:url];
    [docController presentOpenInMenuFromRect:CGRectZero inView:uiBtn animated:true];
    [docController retain];
     const char *str = "Success";
     FREObject retStr;
     FRENewObjectFromUTF8(strlen(str)+1, (const uint8_t *)str, &retStr);
     return retStr;
}

ANE packaging directory:

ane/
     extension.xml
     key.p12
     platform/
          iOS/
               iOSNativeCode.a
               library.swf
               test.epub

extension.xml

<extension xmlns="http://ns.adobe.com/air/extension/3.1">
~~~~

Thanks!