根据旋转更新约束（X，Y，W，H）时出错？

Question

在这里，我使用视觉格式语言来处理自动版式。 如果我将方向从横向还原为纵向-视图无法正确显示。（图像（收缩）和第二个标签（Y位置）） 。 即使在纵向模式下，我在Debugger窗口上也没有收到任何Constraints错误消息。 但是如果我切换到横向模式-其打印内容“无法同时满足约束条件。”

我使用以下代码：

-  (void)addConstraints {

[self.view removeConstraints:self.view.constraints];
NSDictionary *views = NSDictionaryOfVariableBindings(_contactImageProperty,_peopleAllowLabelProperty,_shareCodesDefaultMessageLabelProperty,_continueBtnProperty);
_contactImageProperty.translatesAutoresizingMaskIntoConstraints = NO;
_peopleAllowLabelProperty.translatesAutoresizingMaskIntoConstraints = NO;
_shareCodesDefaultMessageLabelProperty.translatesAutoresizingMaskIntoConstraints = NO;
_continueBtnProperty.translatesAutoresizingMaskIntoConstraints = NO;

// contactImageProperty
NSArray *constraints = [NSArray arrayWithObject:[NSLayoutConstraint constraintWithItem:_contactImageProperty attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeCenterX multiplier:1.0 constant:0.0f]];

constraints = [constraints arrayByAddingObject:[NSLayoutConstraint constraintWithItem:_contactImageProperty attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeHeight multiplier:1.0f constant:200]];

constraints = [constraints arrayByAddingObjectsFromArray:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-30-[_contactImageProperty]" options:0 metrics:nil views:views]];


// peopleAllowLabelProperty
constraints = [constraints arrayByAddingObject:[NSLayoutConstraint constraintWithItem:_peopleAllowLabelProperty attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeCenterX multiplier:1.0f constant:0.0f]];

constraints = [constraints arrayByAddingObject:[NSLayoutConstraint constraintWithItem:_peopleAllowLabelProperty attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeHeight multiplier:1.0f constant:50]];

constraints = [constraints arrayByAddingObjectsFromArray:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[_contactImageProperty]-10-[_peopleAllowLabelProperty]" options:0 metrics:nil views:views]];


// shareCodesDefaultMessageLabelProperty

constraints = [constraints arrayByAddingObject:[NSLayoutConstraint constraintWithItem:_shareCodesDefaultMessageLabelProperty attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeCenterX multiplier:1.0f constant:0.0f]];

constraints = [constraints arrayByAddingObject:[NSLayoutConstraint constraintWithItem:_shareCodesDefaultMessageLabelProperty attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeHeight multiplier:1.0f constant:100]];

constraints = [constraints arrayByAddingObjectsFromArray:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-[_shareCodesDefaultMessageLabelProperty]-|" options:0 metrics:nil views:views]];

constraints = [constraints arrayByAddingObjectsFromArray:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[_peopleAllowLabelProperty]-100-[_shareCodesDefaultMessageLabelProperty]" options:0 metrics:nil views:views]];


// continueBtnProperty

constraints = [constraints arrayByAddingObject:[NSLayoutConstraint constraintWithItem:_continueBtnProperty attribute:NSLayoutAttributeCenterX relatedBy:NSLayoutRelationEqual toItem:self.view attribute:NSLayoutAttributeCenterX multiplier:1.0f constant:0.0f]];

constraints = [constraints arrayByAddingObject:[NSLayoutConstraint constraintWithItem:_continueBtnProperty attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeHeight multiplier:1.0f constant:50]];

constraints = [constraints arrayByAddingObject:[NSLayoutConstraint constraintWithItem:_continueBtnProperty attribute:NSLayoutAttributeWidth relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeWidth multiplier:1.0f constant:300]];

constraints = [constraints arrayByAddingObjectsFromArray:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[_continueBtnProperty]-10-|" options:0 metrics:nil views:views]];

[self.view addConstraints:constraints];

}

- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration{
[super willRotateToInterfaceOrientation:toInterfaceOrientation duration:duration];

NSDictionary *views = NSDictionaryOfVariableBindings(_peopleAllowLabelProperty,_shareCodesDefaultMessageLabelProperty,_continueBtnProperty);
if (UIInterfaceOrientationIsPortrait(toInterfaceOrientation)) {
    [self.view addConstraint:[NSLayoutConstraint constraintWithItem:_contactImageProperty attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeHeight multiplier:1.0f constant:200.0f]];
    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[_peopleAllowLabelProperty]-200-[_shareCodesDefaultMessageLabelProperty]" options:0 metrics:nil views:views]];
}
else {
    [self.view addConstraint:[NSLayoutConstraint constraintWithItem:_contactImageProperty attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeHeight multiplier:1.0f constant:100.0f]];
    [self.view addConstraint:[NSLayoutConstraint constraintWithItem:_shareCodesDefaultMessageLabelProperty attribute:NSLayoutAttributeHeight relatedBy:NSLayoutRelationEqual toItem:nil attribute:NSLayoutAttributeHeight multiplier:1.0f constant:50]];
    [self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:[_peopleAllowLabelProperty]-20-[_shareCodesDefaultMessageLabelProperty]-[_continueBtnProperty]" options:0 metrics:nil views:views]];
}
[self.view setNeedsLayout];
[self.view setNeedsUpdateConstraints];

}

Answer 1

为了缩小图像，应根据高度值对图像的宽度添加约束，以强制图像的高宽比。

对于y位置，您应该向图像，第一个标签，第二个标签和按钮添加3个具有相同高度限制以及相同的尾部和标题空间的隐藏视图。 像这样：

Image
|
hidden view
|
label 1
|
hidden view
|
label 2
|
hidden view
|
button

隐藏视图的高度相等：类似[hiddenView1（== hiddenView2）]

隐藏视图和要素之间的等距空间：谎言V：[topView] -5- [hiddenView] -5- [bottomView]

让我知道是否有帮助。