當使用xib,并使用了AutoLayout之后,當需要適配機型時,或者手動更改視圖的frame的時候,就需要修改約束啦.其實很簡單的. 1.首先從xib中吧改變的約束拖到view上或者ViewController上 @PRoperty (weak, nonatomic) IBOutlet NSLayoutConstraint *topLayout;
機型封裝到單例中 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.還可以為控件自定義一個約束
NSLayoutConstraint *myConstraint =[NSLayoutConstraint constraintWithItem:iSinaButton //子試圖 attribute:NSLayoutAttributeCenterX //子試圖的約束屬性 relatedBy:NSLayoutRelationEqual //屬性間的關系 toItem:self.view//相對于父試圖 attribute:NSLayoutAttributeCenterX//父試圖的約束屬性 multiplier:1.0 constant:0.0];// 固定距離[self.view addConstraint: myConstraint];//為iSinaButton重新添加一個約束新聞熱點
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