如果我在我的应用中有一个包含3个子视图的视图(作为示例),它们之间有以下间距：
TOP – 40分 – SUBVIEW 1 – 60分 – SUBVIEW 2 – 80分 – SUBVIEW 3 – 80分 – BOTTOM
我理解如何使用自动布局来确保每个子视图保持其高度和宽度,并且我可以在3.5或4英寸iPhone屏幕上对齐所有内容.
但我无法弄清楚我需要做出什么样的限制,以便如果它对齐3.5英寸屏幕,然后进入4英寸屏幕,每个间距将按比例增加(例如40点将达到47,60至71,80至95 – 或其左右).
这可能吗？或者我是否需要使元素之间的所有间距相等？ (如果是这样,我怎么还能让它同样调整大小？)
我是Auto Layout的新手,所以如果我遗漏了任何东西,或者还没弄清楚我的意思,请告诉我,谢谢.
解决方法
我不知道有什么简单的方法可以做到这一点.我做了一个所有空间相同的地方,但为了做到这一点,我不得不用不可见的标签填充空格(只是标签没有标题).所以,我把我的4个可见物体和5个“间隔物标签”放在一起.我使4个可见对象都具有明确的高度,并且没有固定高度的间隔物,但设置为完全相同：
-(void)viewDidLoad {
[super viewDidLoad];
NSMutableDictionary *viewsDict = [NSMutableDictionary dictionary];
for (int i=1; i<5; i++) { // Labels with titles
UILabel *b = [[UILabel alloc] initWithFrame:CGRectMake(0,150,44)];
b.text = @"This is my label";
[b setTranslatesAutoresizingMaskIntoConstraints:NO];
[viewsDict setObject:b forKey:[NSString stringWithFormat:@"b%d",i]];
}
for (int i=1; i<6; i++) { // Spacer labels
UILabel *l = [[UILabel alloc ]init];
[l setTranslatesAutoresizingMaskIntoConstraints:NO];
[viewsDict setObject:l forKey:[NSString stringWithFormat:@"l%d",i]];
}
for (id obj in viewsDict.allKeys)
[self.view addSubview:viewsDict[obj]];
NSArray *constraints = [NSLayoutConstraint constraintsWithVisualFormat:@"V:|[l1][b1][l2(==l1)][b2][l3(==l1)][b3][l4(==l1)][b4][l5(==l1)]|"
options:NSLayoutFormatAlignAllLeading
metrics:nil
views:viewsDict];
NSArray *constraints2 = [NSLayoutConstraint constraintsWithVisualFormat:@"|-[b1]"
options:0
metrics:nil
views:viewsDict];
[self.view addConstraints:constraints];
[self.view addConstraints:constraints2];
}
为了使空间不同,我认为你必须使用较长形式的表达约束,而不是视觉格式.以下代码似乎对我有用.我使用与上面相同的视图定义,除了我将标题标签的数量减少到3,将间隔符减少到4以匹配您的问题.相对间距应与示例中的2：3：4：4相同.
NSLayoutConstraint *con1 = [NSLayoutConstraint constraintWithItem:self.view attribute:NSLayoutAttributeTop relatedBy:0 toItem:viewsDict[@"l1"] attribute:NSLayoutAttributeTop multiplier:1 constant:0];
NSLayoutConstraint *con2 = [NSLayoutConstraint constraintWithItem:viewsDict[@"l1"] attribute:NSLayoutAttributeBottom relatedBy:0 toItem:viewsDict[@"b1"] attribute:NSLayoutAttributeTop multiplier:1 constant:0];
NSLayoutConstraint *con3 = [NSLayoutConstraint constraintWithItem:viewsDict[@"b1"] attribute:NSLayoutAttributeBottom relatedBy:0 toItem:viewsDict[@"l2"] attribute:NSLayoutAttributeTop multiplier:1 constant:0];
NSLayoutConstraint *con4 = [NSLayoutConstraint constraintWithItem:viewsDict[@"l2"] attribute:NSLayoutAttributeBottom relatedBy:0 toItem:viewsDict[@"b2"] attribute:NSLayoutAttributeTop multiplier:1 constant:0];
NSLayoutConstraint *con5 = [NSLayoutConstraint constraintWithItem:viewsDict[@"b2"] attribute:NSLayoutAttributeBottom relatedBy:0 toItem:viewsDict[@"l3"] attribute:NSLayoutAttributeTop multiplier:1 constant:0];
NSLayoutConstraint *con6 = [NSLayoutConstraint constraintWithItem:viewsDict[@"l3"] attribute:NSLayoutAttributeBottom relatedBy:0 toItem:viewsDict[@"b3"] attribute:NSLayoutAttributeTop multiplier:1 constant:0];
NSLayoutConstraint *con7 = [NSLayoutConstraint constraintWithItem:viewsDict[@"b3"] attribute:NSLayoutAttributeBottom relatedBy:0 toItem:viewsDict[@"l4"] attribute:NSLayoutAttributeTop multiplier:1 constant:0];
NSLayoutConstraint *con8 = [NSLayoutConstraint constraintWithItem:viewsDict[@"l4"] attribute:NSLayoutAttributeBottom relatedBy:0 toItem:self.view attribute:NSLayoutAttributeBottom multiplier:1 constant:0];
NSLayoutConstraint *con9 = [NSLayoutConstraint constraintWithItem:viewsDict[@"l1"] attribute:NSLayoutAttributeHeight relatedBy:0 toItem:viewsDict[@"l2"] attribute:NSLayoutAttributeHeight multiplier:.66 constant:0];
NSLayoutConstraint *con10 = [NSLayoutConstraint constraintWithItem:viewsDict[@"l1"] attribute:NSLayoutAttributeHeight relatedBy:0 toItem:viewsDict[@"l3"] attribute:NSLayoutAttributeHeight multiplier:.5 constant:0];
NSLayoutConstraint *con11 = [NSLayoutConstraint constraintWithItem:viewsDict[@"l1"] attribute:NSLayoutAttributeHeight relatedBy:0 toItem:viewsDict[@"l4"] attribute:NSLayoutAttributeHeight multiplier:.5 constant:0];
NSLayoutConstraint *con12 = [NSLayoutConstraint constraintWithItem:viewsDict[@"b1"] attribute:NSLayoutAttributeLeading relatedBy:0 toItem:self.view attribute:NSLayoutAttributeLeading multiplier:1 constant:100];
NSLayoutConstraint *con13 = [NSLayoutConstraint constraintWithItem:viewsDict[@"b2"] attribute:NSLayoutAttributeLeading relatedBy:0 toItem:self.view attribute:NSLayoutAttributeLeading multiplier:1 constant:100];
NSLayoutConstraint *con14 = [NSLayoutConstraint constraintWithItem:viewsDict[@"b3"] attribute:NSLayoutAttributeLeading relatedBy:0 toItem:self.view attribute:NSLayoutAttributeLeading multiplier:1 constant:100];
NSArray *constraints = @[con1,con2,con3,con4,con5,con6,con7,con8,con9,con10,con11,con12,con13,con14];
[self.view addConstraints:constraints];
