如何獲得觸摸的觸摸位置開始功能

Question

我試過下面的代碼，但它不起作用。它應該如何修改？

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
{ 
    location = [touches locationInView:self]; 
} 

在我有這樣定義的位置的.h文件：

CGPoint location; 

Answer 1

的(NSSet *)touches會給你的屏幕上的所有當前觸摸。你需要每次觸摸這組數據並獲得它的座標。

這些觸摸是UITouch類的成員。看看UITouch class reference。

，例如，你會怎麼做：

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event { 
    for (UITouch *touch in touches) { 
     CGPoint location = [touch locationInView:self]; 

     // Do something with this location 
     // If you want to check if it was on a specific area of the screen for example 
     if (CGRectContainsPoint(myDefinedRect, location)) { 
      // The touch is inside the rect, do something with it 
      // ... 
      // If one touch inside the rect is enough, break the loop 
      break; 
     } 
    } 
} 

乾杯！