【iOS开发】多屏尺的自动适配 AutoLayout （纯代码方式）

AutoLayout是一种基于约束的，描述性的布局系统。 Auto Layout Is a Constraint-Based, Descriptive Layout System.

使用约束条件来描述布局，view的frame会依据这些约束来进行计算 Describe the layout with constraints, and frames are calculated automatically.

    //-----autoLayout

    [_btn_1 setTranslatesAutoresizingMaskIntoConstraints:NO];

    [_btn_2 setTranslatesAutoresizingMaskIntoConstraints:NO];

    [_btn_3 setTranslatesAutoresizingMaskIntoConstraints:NO];

    [_btn_4 setTranslatesAutoresizingMaskIntoConstraints:NO];

    CGSize winSize = [[iHappySDKSingle shareSingle] getScreenSize];

    CGFloat tpo = _btn_1.frame.origin.y;

    CGFloat hpod = _btn_1.frame.origin.x;

    CGFloat btnH = _btn_1.frame.size.height;

    CGFloat vpod = winSize.width*0.15-btnH;

    NSNumber* tp = [NSNumber numberWithFloat:tpo];

    NSNumber* hd = [NSNumber numberWithFloat:hpod];

    NSNumber* vd = [NSNumber numberWithFloat:vpod];

    NSNumber* bh = [NSNumber numberWithFloat:btnH];

    NSNumber* btm = [NSNumber numberWithFloat:vpod*2];

    NSDictionary *dict1 = NSDictionaryOfVariableBindings(_btn_1,_btn_2,_btn_3,_btn_4);

    NSDictionary *metrics =@{@"hPadding":hd,@"vPadding":vd,@"top":tp,@"btm":btm,@"btnHeight":bh};

    NSString *vfl1 = @"|-hPadding-[_btn_1]-hPadding-|";

[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:vfl1

  options:0

  metrics:metrics

views:dict1]];

    NSString *vfl2 = @"|-hPadding-[_btn_2]-hPadding-|";

[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:vfl2

  options:0

  metrics:metrics

views:dict1]];

    NSString *vfl3 = @"|-hPadding-[_btn_3]-hPadding-|";

[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:vfl3

  options:0

  metrics:metrics

views:dict1]];

    NSString *vfl4 = @"|-hPadding-[_btn_4]-hPadding-|";

[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:vfl4

  options:0

  metrics:metrics

views:dict1]];

    NSString *vfl5 = @"V:|-(<=top)-[_btn_1(btnHeight)]-vPadding-[_btn_2(btnHeight)]-vPadding-[_btn_3(btnHeight)]-vPadding-[_btn_4(btnHeight)]-(>=btm)-|";

    if (_btn_1.hidden) {

        vfl5 = @"V:|-(<=top)-[_btn_2(btnHeight)]-vPadding-[_btn_3(btnHeight)]-vPadding-[_btn_4(btnHeight)]-(>=btm)-|";

    }

[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:vfl5

  options:0

  metrics:metrics

views:dict1]];

- (void)setAutoLayoutForKuang:(UIView*)imgv

{

    UIView * view = self;

    [imgv setTranslatesAutoresizingMaskIntoConstraints:NO];

    NSDictionary *dict1 = NSDictionaryOfVariableBindings(imgv);

    NSDictionary *metrics = @{@"width":[NSNumbernumberWithFloat:imgv.frame.size.width],

                              @"height":[NSNumber numberWithFloat:imgv.frame.size.height],

                              @"top":[NSNumber numberWithFloat:imgv.frame.origin.y]

                              };

    NSString *vfl1 = @"[imgv(width)]";

[view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:vfl1

  options:0

  metrics:metrics

views:dict1]];

    NSString *vfl2 = @"V:[imgv(height)]";

[view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:vfl2

  options:0

  metrics:metrics

views:dict1]];

    [view addConstraint:[NSLayoutConstraint constraintWithItem:imgvattribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:viewattribute:NSLayoutAttributeCenterX multiplier:1 constant:0]];

    [view addConstraint:[NSLayoutConstraint constraintWithItem:imgvattribute:NSLayoutAttributeCenterY relatedBy:NSLayoutRelationEqual toItem:viewattribute:NSLayoutAttributeCenterY multiplier:1 constant:0]];

    //animation

    [UIView animateWithDuration:0.25 animations:^{

        [imgv layoutIfNeeded];

    }];

}