ios中屏幕适配

- (void)viewDidLoad
{
    [super viewDidLoad];

    // 左上角
    // 固定左边和上边,伸缩右边和下边
    self.leftTop.autoresizingMask = UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleBottomMargin | UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

    // 左下角
    // 固定左边和下边,伸缩右边和上边
    self.leftBottom.autoresizingMask = UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

    // 右上角
    // 固定右边和上边,伸缩左边和下边
    self.rightTop.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleBottomMargin | UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;

    // 右下角
    // 固定右边和下边,伸缩左边和上边
    self.rightBottom.autoresizingMask = UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleWidth | UIViewAutoresizingFlexibleHeight;
}

关于ios的控件的AutoresizingMask属性
 个人测试的一些结果

setAutoresizingMask控件的自适应

    UIViewAutoresizingNone                 = ,
    UIViewAutoresizingFlexibleLeftMargin   =  << ,
    UIViewAutoresizingFlexibleWidth        =  << ,
    UIViewAutoresizingFlexibleRightMargin  =  << ,
    UIViewAutoresizingFlexibleTopMargin    =  << ,
    UIViewAutoresizingFlexibleHeight       =  << ,
    UIViewAutoresizingFlexibleBottomMargin =  << 

UIViewAutoresizingNone

UILabel*    label = [[UILabel alloc] initWithFrame:CGRectMake(, , , )];

[label setAutoresizingMask: UIViewAutoresizingNone];  控件相对于俯视图坐标值不变   

CGRectMake(, , , )

UIViewAutoresizingFlexibleWidth：控件的宽度随着父视图的宽度按比例改变    例如

label宽度为      屏幕的宽度为320          当屏幕宽度为480时      label宽度  变为  */
同理
UIViewAutoresizingFlexibleHeight相同

UIViewAutoresizingFlexibleLeftMargin  到屏幕左边的距离随着父视图的宽度按比例改变  

例如
CGRectMake(, , , )];
     屏幕的宽度为320          当屏幕宽度为480时      label宽度  变为  */
控件变为
CGRectMake(, , , )];  

UIViewAutoresizingFlexibleRightMargin
UIViewAutoresizingFlexibleTopMargin
UIViewAutoresizingFlexibleBottomMargin