objective-c - 在 if 语句中组合 contentOffset？ iOS

Question

基本上我想弄清楚的是如何编写以下内容:

//pseudo-code
if (the x value for contentOffset is equal to 
   a figure between, say, 50 and 100) {
   then a specific void is to be executed. 
} 

谢谢!

Answer 1

CGPoint offsetPoint = myScrollView.contentOffset;
float offset = sqrtf(powf(offsetPoint.x,2)+(powf(offsetPoint.y,2));
if (50 < offset && offset < 100) {
   [self myMethod];
}

或者如果您只对一个方向感兴趣，例如垂直方向，

CGFloat offset = myScrollView.contentOffset.y;