UIView convertRect

CGRect newRect = [self.view.window convertRect:self.blueView.frame fromView:self.redView];

NSLog(@"%@", NSStringFromCGRect(newRect));

结果:2015-11-03 19:30:37.123 坐标系转换[24126:1322418] {{150, 150}, {100, 100}}

CGRect newRect = [self.blueView convertRect:CGRectMake(-50, -100, 100, 100) fromView:self.redView];

NSLog(@"%@", NSStringFromCGRect(newRect));

结果:2015-11-03 19:57:35.062 坐标系转换[32304:1340927] {{-100, -150}, {100, 100}}

// 将 CGRectMake(50, 50, 100, 100)  从 self.blueView 坐标系 转换为 self.greenView 坐标系

CGRect newRect = [self.blueView convertRect:CGRectMake(50, 50, 100, 100) toView:self.greenView]

2015-11-03 20:08:47.985 坐标系转换[35697:1350289] {{150, 150}, {100, 100}}

CGRect newRect = [self.blueView convertRect:CGRectMake(50, 50, 100, 100) toView:nil];

2015-11-03 20:12:23.510 坐标系转换[36797:1353910] {{200, 200}, {100, 100}}