来源: 互联网  发布时间: 2014-02-18

NSObject类所支持的一些基本方法
NSObject类所支持的一些基本方法

对象是否class-object或其子类的成员？
-(BOOL) isKindOf:class-object

对象是否class-object的成员？
-(BOOL) isMemberOfClass:class-object

对象是否能够响应selector所指定的方法？
-(BOOL) respondsToSelector:selector

指定的类实例是否能够响应selector所指定的方法？
+(BOOL) instancesRespondsToSelector:selector

对象是指定类的子类吗？
+(BOOL) isSubclassOfClass:class-object

应用指定方法
-(id) performSelector:selector

应用指定方法,传递参数object
-(id) performSelector:selector withObject:object

应用指定方法,传递参数object1和object2
-(id) performSelector:selector withObject:object1 withObject:object2

    

    来源: 互联网  发布时间: 2014-02-18

检测内存

//检测内存
void report_memory(void) {
    static unsigned last_resident_size=0;
    static unsigned greatest = 0;
    static unsigned last_greatest = 0;
    
    struct task_basic_info info;
    mach_msg_type_number_t size = sizeof(info);
    kern_return_t kerr = task_info(mach_task_self(),
                                   TASK_BASIC_INFO,
                                   (task_info_t)&info,
                                   &size);
    if( kerr == KERN_SUCCESS ) {
        int diff = (int)info.resident_size - (int)last_resident_size;
        unsigned latest = info.resident_size;
        if( latest > greatest   )   greatest = latest;  // track greatest mem usage
        int greatest_diff = greatest - last_greatest;
        int latest_greatest_diff = latest - greatest;
        NSLog(@"Mem: %10u (%10d) : %10d :   greatest: %10u (%d)", info.resident_size, diff,
              latest_greatest_diff,
              greatest, greatest_diff  );
    } else {
        NSLog(@"Error with task_info(): %s", mach_error_string(kerr));
    }
    last_resident_size = info.resident_size;
    last_greatest = greatest;
}

    

    来源: 互联网  发布时间: 2014-02-18

UITabBarController取消再次点击已选中tab时回到UINavigationController的rootViewController

设置tabBarController的delegate, 并实现delegate中的tabBarController:shouldSelectViewController方法

 

- (BOOL)tabBarController:(UITabBarController *)tabBarController shouldSelectViewController:(UIViewController *)viewController
{
    AppUtilsLog(NSStringFromSelector(_cmd));
    UIViewController* selectedViewController = tabBarController.selectedViewController;
    if (selectedViewController == viewController) {
        return NO;
    } else {
        return YES;
    }  
}