当使用xib,并使用了AutoLayout之后,当需要适配机型时,或者手动更改视图的frame的时候,就需要修改约束啦.其实很简单的. 1.首先从xib中吧改变的约束拖到view上或者ViewController上 @PRoperty (weak, nonatomic) IBOutlet NSLayoutConstraint *topLayout;
机型封装到单例中 全局都可以使用
+ (UIScreenSizeType)currentScreenSizeType{ if (CGSizeEqualToSize(CGSizeMake(640, 960), [[UIScreen mainScreen] currentMode].size)) { return UIScreenSizeType_640x960; } else if(CGSizeEqualToSize(CGSizeMake(640, 1136), [[UIScreen mainScreen] currentMode].size)){ return UIScreenSizeType_640x1136; }else if(CGSizeEqualToSize(CGSizeMake(750, 1334), [[UIScreen mainScreen] currentMode].size)){ return UIScreenSizeType_750x1334; }else if(CGSizeEqualToSize(CGSizeMake(1242, 2208), [[UIScreen mainScreen] currentMode].size)){ return UIScreenSizeType_1242x2208; } return UIScreenSizeType_000x000;} if([UIScreen currentScreenSizeType] == UIScreenSizeType_640x960){ _topLayout.constant = 40; }else if([UIScreen currentScreenSizeType] == UIScreenSizeType_640x1136){ _topLayout.constant = 40; }else if([UIScreen currentScreenSizeType] == UIScreenSizeType_750x1334){ _topLayout.constant = 40; }else if([UIScreen currentScreenSizeType] == UIScreenSizeType_1242x2208){ _topLayout.constant = 40; }2.还可以为控件自定义一个约束
NSLayoutConstraint *myConstraint =[NSLayoutConstraint constraintWithItem:iSinaButton //子试图 attribute:NSLayoutAttributeCenterX //子试图的约束属性 relatedBy:NSLayoutRelationEqual //属性间的关系 toItem:self.view//相对于父试图 attribute:NSLayoutAttributeCenterX//父试图的约束属性 multiplier:1.0 constant:0.0];// 固定距离[self.view addConstraint: myConstraint];//为iSinaButton重新添加一个约束新闻热点
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