我正在将一个UIView
添加到UIScrollView
中,并将其约束为填充水平空间,除了一些边距。我的可视化约束如下:
@"|-16-[theLineView]-16-|"
我将视图设置为一个像素高,这样它就会显示为一条线,并将其放置在两个文本标签之间。
@"V:[someOtherStuff]-[aTextLabel]-[theLineView]-[anotherLabel]"
然而,我发现线的宽度只扩展到其上下方最长标签的宽度。为什么会这样?P.S 我已经阅读了此链接:http://developer.apple.com/library/ios/#technotes/tn2154/_index.html。
代码
以下是一个测试项目中视图控制器代码的全部内容,该项目在iPad模拟器上出现了此问题。
- (void)viewDidLoad
{[super viewDidLoad];}
self.scrollView = [[UIScrollView alloc] init];
self.scrollView.translatesAutoresizingMaskIntoConstraints = NO;
self.scrollView.backgroundColor = [UIColor greenColor];
[self.view addSubview:self.scrollView];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"|[scrollView]|"
options:0
metrics:0
views:@{@"scrollView":self.scrollView}]];
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|[scrollView]|"
options:0
metrics:0
views:@{@"scrollView":self.scrollView}]];
self.line1 = [[UIView alloc] init];
self.line2 = [[UIView alloc] init];
self.label1 = [[UILabel alloc] init];
self.label2 = [[UILabel alloc] init];
self.label3 = [[UILabel alloc] init];
for (UILabel *label in @[self.label1, self.label2, self.label3])
{
label.text = @"I am a label and I am long enough that I can be multiline on an iphone but single on ipad";
}
for (UIView *view in @[self.line1, self.line2, self.label1, self.label2, self.label3])
{
view.translatesAutoresizingMaskIntoConstraints = NO;
view.backgroundColor = [UIColor redColor];
[self.scrollView addSubview:view];
}
//horizontal layout - all views/labels should fill the horizontal space expect for margin
for (UIView *view in @[self.line1, self.line2, self.label1, self.label2, self.label3])
{
NSArray *constraints = [NSLayoutConstraint constraintsWithVisualFormat:@"|-16-[view]-16-|"
options:0
metrics:0
views:@{@"view":view}];
[self.scrollView addConstraints:constraints];
}
//vertical layout - stack em up
[self.scrollView addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"V:|-[lab1]-[line1(==1)]-[lab2]-[line2(==1)]-[lab3]-|"
options:0
metrics:0
views:@{@"lab1":self.label1, @"line1":self.line1, @"lab2":self.label2, @"line2":self.line2, @"lab3":self.label3}]];
}
UIView
上还有其他的约束吗? - Yazid