Question

我在使用autolayout时遇到了一个问题（我是新手），尽管我的约束功能正常（水平居中，我想要的是垂直间距），当我向横向移动时，底部按钮消失

我知道发生这种情况是因为我基于纵向方向视图约束了我的对象，当我们移动到横向时，当高度和宽度值移动时，这不再适用。在改变方向时，我真的不知道如何解释这些变化。有什么建议吗？

下面的代码和截图：

-(void)setConstraints {
    [self.view removeConstraints:self.view.constraints];

    UIButton *cameraButton = self.cameraButton;
    UILabel *camera = self.videoLabel;
    UIButton *libraryButton = self.libraryButton;
    UILabel *library = self.libraryLabel;


    NSDictionary *views = NSDictionaryOfVariableBindings(camera, cameraButton, libraryButton, library);

    NSDictionary *metrics = @{@"horizontalSpacing":@500.0, @"verticalSpacing":@125};


    //set up top button to be horizontally centered
    NSArray *constraints = [NSLayoutConstraint constraintsWithVisualFormat:@"|-[cameraButton]-|"
                                                                   options:0
                                                                   metrics:nil
                                                                     views:views];

    //set up top button vertical from top of superview
    constraints = [constraints arrayByAddingObjectsFromArray:
                   [NSLayoutConstraint constraintsWithVisualFormat: @"V:|-175-[cameraButton]"
                                                           options:0
                                                           metrics:nil
                                                             views:views]];
    //set up top button label to be horizontally centered
    constraints = [constraints arrayByAddingObjectsFromArray:
                   [NSLayoutConstraint constraintsWithVisualFormat: @"|-[camera]-|"
                                                           options:0
                                                           metrics:nil
                                                             views:views]];

    //set up second button to be horizontally centered
    constraints = [constraints arrayByAddingObjectsFromArray:
                   [NSLayoutConstraint constraintsWithVisualFormat: @"|-[libraryButton]-|"
                                                           options:0
                                                           metrics:nil
                                                             views:views]];
    //set up label for second button to be horizontally centered
    constraints = [constraints arrayByAddingObjectsFromArray:
                   [NSLayoutConstraint constraintsWithVisualFormat: @"|-[library]-|"
                                                           options:0
                                                           metrics:nil
                                                             views:views]];

    //set up vertical constraints by spacing ALL objects appropriately
    constraints = [constraints arrayByAddingObjectsFromArray:
                   [NSLayoutConstraint constraintsWithVisualFormat: @"V:[cameraButton]-[camera]-verticalSpacing-[libraryButton]-[library]"
                                                           options:0
                                                           metrics:metrics
                                                             views:views]];


    self.libraryLabel.textAlignment = NSTextAlignmentCenter;
    self.videoLabel.textAlignment = NSTextAlignmentCenter;

    self.libraryLabel.backgroundColor = [UIColor redColor];

    [self.view addConstraints:constraints];

}

Answer 1

你得到了你所要求的。如果那不是你想要的，那就不要求了！

考虑你的垂直约束：

@"V:|-175-[cameraButton]"
@"V:[cameraButton]-[camera]-verticalSpacing-[libraryButton]-[library]"

从上到下构成一系列约束。当然，如果屏幕更短而不是175加上verticalSpacing加上其他视图的尺寸和最小间距，则底部视图将偏离屏幕底部。

如果那不是您想要的，请更改您的设计，使其不是您所获得的。例如，从上到下放置一些视图，从下到上放置一些视图。或者允许你的一些空格改变为超视图高度的百分比。

如何避免使用程序化自动布局进行硬编码

1 个答案: