使用自动布局（以编程方式）水平对齐 UIButton

Question

我正在尝试水平放置 2 个 UIButton，但没有成功

1. 我正在以编程方式使用自动布局约束。

2. 我不想将它们放在容器中并将中心与该容器对齐。

   NSDictionary *metrics = @{@"kLeftPadding":@(kLeftPadding),
                             @"kRightPadding":@(kRightPadding),
                             @"kMiddlePadding":@(kMiddlePadding),
                             @"kBottomPadding":@(kBottomPadding)};
   NSDictionary *constrainedViews = @{@"titleLabel": self.titleLabel,
                                      @"btnToday" : self.btnToday,
                                      @"btnPickaDay" : self.btnPickaDay,
                                      @"dividerView" : dividerView};
   NSArray *contraints = @[@"V:|-[titleLabel]-kBottomPadding-[btnToday(==40)]-[btnPickaDay(==btnToday)]-kBottomPadding-[dividerView]-0-|",
                           @"H:|-kLeftPadding-[titleLabel]-|",
                           @"H:|-kLeftPadding-[btnToday]-kMiddlePadding-[btnPickaDay(==btnToday)]-kRightPadding-|",
                           @"H:|-0-[dividerView]-0-|"];
   

第二个按钮从第一个结束的地方开始，但在下一行，而不是同一行。

Answer 1

我已经尝试过你的代码，但它已经崩溃了，所以根据你的问题，你只需要编写下面的代码。

UILabel *lblText = [UILabel new];
[lblText setText:@"Some Title Text"];
[lblText setTranslatesAutoresizingMaskIntoConstraints:NO];
[self.view addSubview:lblText];

UIButton *btnRed = [UIButton new];
[btnRed setBackgroundColor:[UIColor redColor]];
[btnRed setTranslatesAutoresizingMaskIntoConstraints:NO];
[self.view addSubview:btnRed];

UIButton *btnGreen = [UIButton new];
[btnGreen setBackgroundColor:[UIColor greenColor]];
[btnGreen setTranslatesAutoresizingMaskIntoConstraints:NO];
[self.view addSubview:btnGreen];

UIView *vwLine = [UIView new];
[vwLine setBackgroundColor:[UIColor blueColor]];
[vwLine setTranslatesAutoresizingMaskIntoConstraints:NO];
[self.view addSubview:vwLine];


NSDictionary *dictViews = @{@"red":btnRed,@"green":btnGreen,
                            @"line":vwLine,@"lbl":lblText};

NSDictionary *dictMetrics = @{@"height":@(40),@"offset":@(-40)};
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-20-[red]-0-[green(==red)]-20-|" options:0 metrics:nil views:dictViews]];

[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-20-[line]-20-|" options:0 metrics:nil views:dictViews]];

[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-20-[lbl]-20-|" options:0 metrics:nil views:dictViews]];

[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-(height)-[lbl]-(height)-[red(height)]-(offset)-[green(==red)]-50-[line(2)]" options:0 metrics:dictMetrics views:dictViews]];

结果：

希望它能帮助您解决问题。如果有任何疑问，请告诉我。