?
?
*/ 以下不常用 ?
// 務必記住
// 1.當給某個控件設置約束時候,必須關閉這個控件上autoresing
// 2.當給一個控件添加約束時候,必須保證這個控件在控制器View的層次結構中
- (void)viewDidLoad {
??? [super viewDidLoad];
??
??? UIView *redView = [[UIView alloc] init];
??? redView.backgroundColor = [UIColor redColor];
??? [self.view addSubview:redView];
???
??? UIView *blueView = [[UIView alloc] init];
??? blueView.backgroundColor = [UIColor blueColor];
??? [self.view addSubview:blueView];
???
//? Constraint 約束
/*
?第一個參數 Item
?1.需要約束控件
?第二個參數 約束的屬性
?NSLayoutAttributeLeft = 1, 左邊
?NSLayoutAttributeRight,? 右邊
?NSLayoutAttributeTop,??? 頂部
?NSLayoutAttributeBottom, 下邊
?NSLayoutAttributeLeading, 左邊
?NSLayoutAttributeTrailing, 右邊
?NSLayoutAttributeWidth, ? 寬
?NSLayoutAttributeHeight,? 高
?NSLayoutAttributeCenterX, 水平中線
?NSLayoutAttributeCenterY, 垂直中線
?第三個參數就是 關系
?typedef NS_ENUM(NSInteger, NSLayoutRelation) {
?NSLayoutRelationLessThanOrEqual = -1,? "<="
?NSLayoutRelationEqual = 0,????????????? "=="
?NSLayoutRelationGreaterThanOrEqual = 1, ">="
?};
第四個參數 參照物(參照控件)
?
第五個參數 參照控件的屬性
?
multiplier 乘
?
constant ? +
?
公式
item1.attribute <relation> item2.attribute * multiplier + constant
?
?*/
// 務必記住
// 1.當給某個控件設置約束時候,必須關閉這個控件上autoresing
?? blueView.translatesAutoresizingMaskIntoConstraints = NO;
??? redView.translatesAutoresizingMaskIntoConstraints = NO;
// 2.當給一個控件添加約束時候,必須保證這個控件在控制器View的層次結構中
???
//? 添加藍色的View頂部
??? NSLayoutConstraint *blueTop = [NSLayoutConstraint constraintWithItem:blueView attribute:NSLayoutAttributeTop? relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeTop multiplier:1 constant:20];
???
??? [self.view addConstraint:blueTop];
???
??? //? 添加藍色的View左邊
??? NSLayoutConstraint *blueLeft = [NSLayoutConstraint constraintWithItem:blueView attribute:NSLayoutAttributeLeft? relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeLeft multiplier:1 constant:20];
???
??? [self.view addConstraint:blueLeft];
??? //? 添加藍色的View右邊
??? NSLayoutConstraint *blueRight = [NSLayoutConstraint constraintWithItem:blueView attribute:NSLayoutAttributeRight? relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeRight multiplier:1 constant:-20];
??? [self.view addConstraint:blueRight];
??? //? 添加藍色的View的高度
??? NSLayoutConstraint *blueHeigt = [NSLayoutConstraint constraintWithItem:blueView attribute:NSLayoutAttributeHeight? relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeNotAnAttribute multiplier:1 constant:100];
??? [self.view addConstraint:blueHeigt];
???
//? 添加紅色view上面約束
//? 紅色的頂部
??? NSLayoutConstraint *redTop = [NSLayoutConstraint constraintWithItem:redView attribute:NSLayoutAttributeTop? relatedBy:NSLayoutRelationEqual toItem:blueView attribute:NSLayoutAttributeBottom multiplier:1 constant:20];
??? [self.view addConstraint:redTop];
//? 紅色view與藍色view右邊對齊
??? NSLayoutConstraint *redRight = [NSLayoutConstraint constraintWithItem:redView attribute:NSLayoutAttributeRight? relatedBy:NSLayoutRelationEqual toItem:blueView attribute:NSLayoutAttributeRight multiplier:1 constant:0];
??? [self.view addConstraint:redRight];
??
??? //? 紅色view與藍色view的高度相同
??? NSLayoutConstraint *redHeight = [NSLayoutConstraint constraintWithItem:redView attribute:NSLayoutAttributeHeight? relatedBy:NSLayoutRelationEqual toItem:blueView attribute:NSLayoutAttributeHeight multiplier:1 constant:0];
??? [self.view addConstraint:redHeight];
???
???
??? //? 紅色view與藍色view的高度相同
??? NSLayoutConstraint *redWidth = [NSLayoutConstraint constraintWithItem:redView attribute:NSLayoutAttributeWidth? relatedBy:NSLayoutRelationEqual toItem:blueView attribute:NSLayoutAttributeWidth multiplier:0.5 constant:0];
??? [self.view addConstraint:redWidth];
??? }
動畫
? ? self.vSpaceConstraint.constant += 100;
??? self.hSpaceContraint.constant += 100;
??? self.widthcontraint.constant += 100;
??? self.heightContraint.constant += 100;
???
???
??? [UIView animateWithDuration:1 animations:^{
//????? 這個方法是讓重新布局界面
//????? 計算約束,然后調節控件的位置
??????? [self.view layoutIfNeeded];
??? }];
——Vfl 語法
偶爾用 ?
// ?一定要關閉autoresizing?
- (void)viewDidLoad {
??? [super viewDidLoad];
???
//? 1.創建子控件,添加加到控制器view中
??? UIView *blueView = [[UIView alloc] init];
??? blueView.backgroundColor = [UIColor blueColor];
??? [self.view addSubview:blueView];
???
??? UIView *redView = [[UIView alloc] init];
??? redView.backgroundColor = [UIColor redColor];
??? [self.view addSubview:redView];
???
//? 2.關閉autoresizing
???
??? blueView.translatesAutoresizingMaskIntoConstraints = NO;
??? redView.translatesAutoresizingMaskIntoConstraints = NO;
???
//? 3.通過VFL添加約束
// ? options 對齊方式
//? 水平方向
??? NSArray *hConstraints = [NSLayoutConstraint constraintsWithVisualFormat:@"H:|-20-[blueView]-20-|" options:NSLayoutFormatAlignAllTop metrics:nil views:@{@"blueView":blueView}];
??? [self.view addConstraints:hConstraints];
???
//? 豎直方向
????? NSArray *vConstraints = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|-20-[blueView(100)]-20-[redView(==blueView)]" options:NSLayoutFormatAlignAllRight metrics:nil views:@{@"blueView":blueView,@"redView":redView}];
???
??? [self.view addConstraints:vConstraints];
???
//? VFL 不能參與運算
//??? NSArray *h1Constraints = [NSLayoutConstraint constraintsWithVisualFormat:@"H:[redView(==blueView * 0.5)]" options:NSLayoutFormatAlignAllTop metrics:nil views:@{@"blueView":blueView,@"redView":redView}];
//???
//??? [self.view addConstraints:h1Constraints];
??? NSLayoutConstraint *redW = [NSLayoutConstraint constraintWithItem:redView attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:blueView attribute:NSLayoutAttributeWidth multiplier:0.5 constant:0];
??? [self.view addConstraint:redW];
???
}
