相关疑难解决方法(0)

我想在NSURLSession上创建一个类别.该应用程序编译好,但当我尝试调用我得到的类别方法

-[__NSCFURLSession doSomething]: unrecognized selector sent to instance 0xbf6b0f0
<unknown>:0: error: -[NSURLSession_UPnPTests testCategory] : -[__NSCFURLSession doSomething]: unrecognized selector sent to instance 0xbf6b0f0

很奇怪,这是我为了显示问题而构建的测试类.NSString上的类别工作正常,但NSURLSession上的类别无法在运行时找到该方法.我怀疑这是内部的东西.

意见请:-)

#import <XCTest/XCTest.h>

@interface NSString (test)
-(void) doSomethingHere;
@end

@implementation NSString (test)
-(void) doSomethingHere {
    NSLog(@"Hello string");
}
@end

@interface NSURLSession (test)
-(void) doSomething;
@end

@implementation NSURLSession (test)
-(void) doSomething {
    NSLog(@"Hello!!!!");
}
@end

@interface NSURLSession_UPnPTests : XCTestCase
@end

@implementation NSURLSession_UPnPTests
-(void) testCategory {
    [@"abc" doSomethingHere];
    NSURLSession *session = [NSURLSession sharedSession];
    [session doSomething];
}
@end