1、CGRectInset(<#CGRect rect#>, <#CGFloat dx#>, <#CGFloat dy#>)
中心相同

CG_EXTERN CGRect CGRectInset(CGRect rect, CGFloat dx, CGFloat dy)
    CG_AVAILABLE_STARTING(__MAC_10_0, __IPHONE_2_0);

UIView *view = [[UIView alloc] init];
    view.frame = CGRectMake(100, 100, 100, 100);
    view.backgroundColor
 
 = [UIColor orangeColor];
    UIView *otherView = [[UIView alloc] init];

    otherView.frame = CGRectInset(view.frame, 2, 4);
    otherView.backgroundColor = [UIColor yellowColor];

    [self.view addSubview:view];
    [self.view addSubview:otherView];

2、CGRectOffset(<#CGRect rect#>, <#CGFloat dx#>, <#CGFloat dy#>)
位置不同

CG_EXTERN CGRect CGRectOffset(CGRect rect, CGFloat dx, CGFloat dy)
    CG_AVAILABLE_STARTING(__MAC_10_0, __IPHONE_2_0);

UIView *view = [[UIView alloc] init];
    view.frame = CGRectMake(100, 100, 100, 100);
    view.backgroundColor = [UIColor purpleColor];
    UIView *otherView = [[UIView alloc] init];

    otherView.frame
 
 = CGRectOffset(view.frame, 2, 4);
    otherView.backgroundColor = [UIColor yellowColor];

    [self.view addSubview:view];
    [self.view addSubview:otherView];

3、CGRectGetMidY(<#CGRect rect#>) 、 CGRectGetMidX(<#CGRect rect#>)
獲取中心點座標

    CG_EXTERN CGFloat CGRectGetMidX(CGRect rect)
    CG_AVAILABLE_STARTING(__MAC_10_0, __IPHONE_2_0);
    CG_EXTERN CGFloat CGRectGetMidY(CGRect rect)
    CG_AVAILABLE_STARTING(__MAC_10_0, __IPHONE_2_0);

UIView *view = [[UIView alloc] init];
    view.frame = CGRectMake(100, 100, 100, 100);
    view.backgroundColor = [UIColor purpleColor];
    UIView *otherView = [[UIView alloc] init];

    otherView.frame = CGRectOffset(view.frame, 2, 4);
    otherView.backgroundColor = [UIColor yellowColor];

    CGFloat centerX = CGRectGetMidX(view.frame);
    CGFloat centerY = CGRectGetMidX(view.frame);

    NSLog(@"%f",centerX);
    NSLog(@"%f",centerY);


    [self.view addSubview:view];
    [self.view addSubview:otherView];

4、CGRectIntersectsRect(<#CGRect rect1#>, <#CGRect rect2#>)
是否相交

In English,intersect means 交集

CG_EXTERN bool CGRectIntersectsRect(CGRect rect1, CGRect rect2)
    CG_AVAILABLE_STARTING(__MAC_10_0, __IPHONE_2_0);

    UIView *view = [[UIView alloc] init];
    view.frame = CGRectMake(100, 100, 100, 100);
    view.backgroundColor = [UIColor purpleColor];
    UIView *otherView = [[UIView alloc] init];

    otherView.frame = CGRectOffset(view.frame, 2, 4);
    otherView.backgroundColor = [UIColor yellowColor];

    [self.view addSubview:view];
    [self.view addSubview:otherView];

    BOOL isIntersect =  CGRectIntersectsRect(view.frame, otherView.frame);
    NSLog(@"%d",isIntersect);

5、CGRectIntersection(<#CGRect r1#>, <#CGRect r2#>)
相交區域

CG_EXTERN CGRect CGRectIntersection(CGRect r1, CGRect r2)
    CG_AVAILABLE_STARTING(__MAC_10_0, __IPHONE_2_0);

UIView *view = [[UIView alloc] init];
    view.frame = CGRectMake(100, 100, 100, 100);
    view.backgroundColor = [UIColor purpleColor];
    UIView *otherView = [[UIView alloc] init];

    otherView.frame = CGRectOffset(view.frame, 2, 4);
    otherView.backgroundColor = [UIColor yellowColor];

    [self.view addSubview:view];
    [self.view addSubview:otherView];
    CGRect rect = CGRectIntersection(view.frame, otherView.frame);
    NSLog(@"%@",NSStringFromCGRect(rect));

    UIView *intersectView = [[UIView alloc] init];
    intersectView.frame = rect;
    intersectView.backgroundColor = [UIColor redColor];
    [self.view addSubview:intersectView];

6、CGRectIsNull(<#CGRect rect#>)
是否為空

CG_EXTERN bool CGRectIsNull(CGRect rect)
    CG_AVAILABLE_STARTING(__MAC_10_0, __IPHONE_2_0);

UIView *view = [[UIView alloc] init];
    view.frame = CGRectMake(100, 100, 100, 100);
    view.backgroundColor = [UIColor orangeColor];
    [self.view addSubview:view];

    UIView *view1 = [[UIView alloc] init];
    view1.frame = CGRectMake(100, 150, 100, 100);
    view.backgroundColor = [UIColor yellowColor];
    [self.view addSubview:view1];

    CGRect intersectRect = CGRectIntersection(view.frame, view1.frame);
    //0說明有交集
    NSLog(@"%d",CGRectIsNull(intersectRect));

7、CGRectEqualToRect(<#CGRect rect1#>, <#CGRect rect2#>)
判斷兩個矩形是否相同，包括位置和形狀

CG_EXTERN bool CGRectEqualToRect(CGRect rect1, CGRect rect2)
    CG_AVAILABLE_STARTING(__MAC_10_0, __IPHONE_2_0);

2016年12月21日更新

iOS中的座標轉換：
經常遇到的需求是把cell上的子檢視的座標轉為視窗的座標，我們需要的轉換如下：
[cell convertPoint:tmpImage.center toView:destinationView] 這裡的cell的位置不能傳入子檢視的座標，需要注意一下。