iOS - 將手指拖動到網格視圖上

Question

我有一個子視圖網格的超級視圖。當我拖出/移出子視圖時，我想改變它的屬性（類似iPhone上的UIKeyboard）。子視圖是UIButton子類。

我在想我需要從superview做一些觸摸轉發，但我不清楚它是如何工作的。這些方法的正確組合是什麼？

– touchesBegan:withEvent:
– touchesMoved:withEvent:
– touchesEnded:withEvent:
– touchesCancelled:withEvent:

hitTest:withEvent:

Answer 1

我認爲你可以使用：

– touchesBegan:withEvent: 
– touchesMoved:withEvent: 
– touchesEnded:withEvent: 
– touchesCancelled:withEvent: 

你的上海華。

一種可能的方法是在touchesMoved中識別哪個子視圖當前「處於觸摸之下」（即觸摸位置在哪）並相應地改變其狀態。

-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event 
{ 
    UITouch *touch = [[event allTouches] anyObject]; 
    CGPoint location = [touch locationInView:touch.view]; 
    if(CGRectContainsPoint(subview1.frame, location)) { 
     ... 
    } 
} 

touchesBegan和touchesEnded不會在其中發揮了重要作用;他們只會有用於開始和結束您在touchesMoved中所做的「跟蹤」。

-(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
{ 
    NSSet *allTouches = [event allTouches]; 
    <save initial touch if you need it> 
} 


-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event 
{ 
    <do whatever> 
}