Question

我如何通过

-(void)explosionFromPoint:(CGPoint)explosionPoint withSprite:(CCSprite*)sprite;

中的

[self performSelector:@selector(//Right here) withObject:nil afterDelay:3];？

你不能将整个选择器放在@selector()内，withObject首先只允许一个对象被传递，我也不理解如何使用它。

如何在延迟后传递带有对象的方法？我也尝试了一种解决方法，我打电话给

[self performSelector:@selector(waitExplosion) withObject:nil afterDelay:3]; 然后运行动作本身，[self explosionFromPoint:c0TileCoord withSprite:bomb];，但这是一个非常糟糕的方法，因为我必须重新声明变量，它只是坏。

如何在延迟后传递带有对象的方法？

Answer 1

您可以使用dispatch_after。

double delayInSeconds = 2.0;
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
    [self explosionFromPoint:aPoint withSprite:sprite]; 
});

在块外部定义aPoint和sprite。

Answer 2

如果要使用 performSelector： 将多个参数传递给方法，请将所有参数保留在NSArray或NSDictionary中，然后传递像

那样的数组/字典

  [self performSelector:@selector(testWith:) withObject:array afterDelay:3];

修改

  NSArray *array =[NSArray arrayWithObjects:@"arg1",@"arg2"];
 [self performSelector:@selector(testWith:) withObject:array afterDelay:3];


 -(void)testWith:(NSArray *)array
 {

   NSString * arg1 =[array objectAtIndex:0];// first argument
   NSString *arg2 = [array objectAtIndex:1];// second argument
   // do other stuff
 }

Answer 3

您可以使用的另一种方法是将NSArray或NSMutableArray作为参数传递给您的方法。一个例子：

NSString *firstItem = @"first Item";
NSNumber *secondItem = [[NSNumber numberWithBool:YES];
YourCustomObject *thirdItem= [[YourCustomObject alloc] init];

//your array to pass
NSArray *arrayToPass = [[NSArray arrayWithObjects:firstItem, secondItem, thirdItem, nil];

//call you method after delay and pass all the objects:
[self oerformSelector:@selector(doStuffWithMultipleParams:) withObject:arrayToPass afterDelay:3.0f];

该方法可以这样使用：

 - (void)doStuffWithMultipleParams:(NSArray *)passedArray{
    String *s; 
    BOOL b;
    YourCustomObject *obj;
    if ([[passedArray objectAtIndex:0] isKindOfClass:[NSString class]]){
        s = [passedArray objectAtIndex:0];
    }
    if ([[passedArray objectAtIndex:1] isKindOfClass:[NSNumber class]]){
        b = [[passedArray objectAtIndex:1] boolValue];
    }
    if ([[passedArray objectAtIndex:1] isKindOfClass:[YourCustomObject class]]){
        obj = [passedArray objectAtIndex:2];
    }
    if (s || b || obj){
        //now do stuff with these objects
    }


}

Answer 4

根据documentation。对于您的情况，您可以使用NSObject的另一种方法。即

- (id)performSelector:(SEL)aSelector withObject:(id)object1 withObject:(id)object2;

但不幸的是，在这种方法中，你不能给出延迟。

如何将多个对象传递给延迟方法？

4 个答案: