【iOS】屏幕旋转，屏幕自适应方向变化

1. iOS有四个方向的旋转，为了保证自己的代码能够支持旋转，我们必须首先处理一个函数：

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {

    return YES;
}

 

2. 这个函数时用来确定我们的应用所支持的旋转方向。如果想要支持每个方向则直接返回YES就行，还可以单独判断某一方向：

 

- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {

    if (interfaceOrientation==UIInterfaceOrientationLandscapeLeft) {

        //left

    }

    if (interfaceOrientation==UIInterfaceOrientationLandscapeRight) {

        //right

    }

    if (interfaceOrientation==UIInterfaceOrientationPortrait) {

        //up

    }

    if (interfaceOrientation==UIInterfaceOrientationPortraitUpsideDown) {

        //down

    }

    return YES;
}

 

 

3. 当然旋转还有一些函数可触发：

//旋转方向发生改变时

-(void)willAnimateRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
}
//视图旋转动画前一半发生之前自动调用

-(void)willAnimateFirstHalfOfRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
}
//视图旋转动画后一半发生之前自动调用

-(void)willAnimateSecondHalfOfRotationFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation duration:(NSTimeInterval)duration {
}
//视图旋转之前自动调用

-(void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
}
//视图旋转完成之后自动调用

-(void)didRotateFromInterfaceOrientation:(UIInterfaceOrientation)fromInterfaceOrientation {
}
//视图旋转动画前一半发生之后自动调用

-(void)didAnimateFirstHalfOfRotationToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation {
}