在iOS中以特定间隔调用操作

我试图在Cocos3d中调用包含ccactioninterval的函数.我想在特定的时间间隔调用该函数.当我尝试NSTimer时,我发现它有时会工作,有时却不会.

NSTimer makeTarget=[NSTimer scheduledTimerWithTimeInterval:2.0 target:self SELEctor:@SELEctor(createTargets) userInfo:nil repeats:YES];

这里createTargets是包含动作事件的函数.当我运行该功能时,直接工作正常一次.当我尝试安排它时出现问题.我尝试过针对相关问题已经解释的不同方法.但没有什么对我有用. . . .

这是代码

-(void) addTargets {      
    NSTimer *makeTarget = [NSTimer scheduledTimerWithTimeInterval:2.0
              target:self SELEctor:@SELEctor(createTargets) userInfo:nil repeats:YES]; 
}

-(void)createTargets {
    CC3MeshNode *target = (CC3MeshNode*)[self getNodenamed: @"obj1"];    
    int minVal=-5;
    int maxVal=5;    
    float avgVal; 
    avgVal = maxVal- minVal;      
    float Value = ((float)arc4random()/ARC4RANDOM_MAX)*avgVal+minVal ;          
    [target setLOCATIOn:cc3v(Value,5.0,0.0)];    
    CCActionInterval *moveTarget = [CC3MoveBy actionWithDuration:7.0 moveBy:cc3v(0.0,-10.0,0.0)];     
    CCActionInterval *removeTarget = [CCCallFuncN actionWithTarget:self SELEctor:@SELEctor(removeTarget:)];       
    [target runAction:[CCSequence actionOne:moveTarget two:removeTarget]];   
}

-(void)removeTarget:(CC3MeshNode*)targ {  
    [self removeChild:targ];  
    targ=nil; 
}

NSTimer * makeTargetTimer = [NSTimer scheduledTimerWithTimeInterval:2.0 target:self SELEctor:@SELEctor(createTargets) userInfo:nil repeats:YES];
self.makeTargetTimer = makeTargetTimer // Save to a property for later use (or just use an iVar)

BOOL isInvalidated = [self.makeTargetTimer isValid];

- (void) dealloc {
    [_makeTargetTimer invalidate];  // Stops the timer from firing (Assumes ARC)
}

[[NSRunLoop currentRunLoop] addTimer:makeTargetTimer forMode:NSRunLoopCommonModes];