ios 如何以编程方式仅设置 UILabel 的宽度和高度以及约束
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How to set UILabel only width and height and constraints programmatically
提问by Varun Naharia
I want to create a UILabel programmatically with height, width and then I want to add constraints to it also programmatically for positioning the UILabel.
我想以编程方式创建一个具有高度、宽度的 UILabel，然后我想以编程方式向它添加约束以定位 UILabel。
Update:
更新：
I want to create UI like this:
我想创建这样的用户界面：
How to create this UI All programatically
如何以编程方式创建此 UI
Code to create one label label1similarly I created two more label label2and label3
代码来创建一个标签，label1同样地，我创建了两个多标签label2和label3
UILabel *label1 = [[UILabel alloc]init];
label1.font = TitleFont;
label1.numberOfLines=0;
label1.text= @"Descriptions";
label1.lineBreakMode=NSLineBreakByWordWrapping;
[label1 sizeToFit];
label1.backgroundColor=[UIColor blueColor];
label1.textColor=[UIColor blackColor];
label1.translatesAutoresizingMaskIntoConstraints = NO;
[self.view addSubview:label1];
And now I am able to add horizontal constraints them with this code
现在我可以使用此代码添加水平约束
[self.view addConstraints:[NSLayoutConstraint constraintsWithVisualFormat:@"H:|-[label1]-|" options:NSLayoutFormatDirectionLeadingToTrailing metrics:nil views:NSDictionaryOfVariableBindings(label1)]];
I am also able to set vertical constraint with view but I am unable to set constraint with from one label to another.
我还可以设置视图的垂直约束，但我无法设置从一个标签到另一个标签的约束。
回答by EI Captain v2.0
To create label with height and width constraints here is the constraints...And don't forget to add label in to view with addSubviewmethod
在这里创建具有高度和宽度约束的标签是约束......并且不要忘记使用addSubview方法添加标签以查看
UILabel *Label = [[UILabel alloc] init];
[Label setTranslatesAutoresizingMaskIntoConstraints:NO];
[self.view addSubview:Label];
// Width constraint
[Label addConstraint:[NSLayoutConstraint constraintWithItem:Label
attribute:NSLayoutAttributeWidth
relatedBy:NSLayoutRelationEqual
toItem:nil
attribute: NSLayoutAttributeNotAnAttribute
multiplier:1
constant:200]];
// Height constraint
[Label addConstraint:[NSLayoutConstraint constraintWithItem:Label
attribute:NSLayoutAttributeHeight
relatedBy:NSLayoutRelationEqual
toItem:nil
attribute: NSLayoutAttributeNotAnAttribute
multiplier:1
constant:21]];
Swift 4:
斯威夫特 4：
label.translatesAutoresizingMaskIntoConstraints = false
label.addConstraint(NSLayoutConstraint(item: label, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 21))
label.addConstraint(NSLayoutConstraint(item: label, attribute: .width, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 200))
And In Swift
并且在斯威夫特
Label.setTranslatesAutoresizingMaskIntoConstraints(false)
self.view.addSubview(Label)
Label.addConstraint(NSLayoutConstraint(item: Label, attribute: .Height, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1, constant: 21))
Label.addConstraint(NSLayoutConstraint(item: Label, attribute: .Width, relatedBy: .Equal, toItem: nil, attribute: .NotAnAttribute, multiplier: 1, constant: 200))
Check this linkfor more detail
查看此链接了解更多详情
UPDATE
As you update your question, here is my updated answer...
更新
当你更新你的问题时，这是我更新的答案......
UILabel *Label1 = [[UILabel alloc] init];
[Label1 setTranslatesAutoresizingMaskIntoConstraints:NO];
UILabel *Label2 = [[UILabel alloc] init];
[Label2 setTranslatesAutoresizingMaskIntoConstraints:NO];
Label1.text = @"Label1";
Label1.backgroundColor = [UIColor blueColor];
Label2.text = @"Label2";
Label2.backgroundColor = [UIColor redColor];
[self.view addSubview:Label1];
[self.view addSubview:Label2];
// Width constraint
[Label1 addConstraint:[NSLayoutConstraint constraintWithItem:Label1
attribute:NSLayoutAttributeWidth
relatedBy:NSLayoutRelationEqual
toItem:nil
attribute: NSLayoutAttributeNotAnAttribute
multiplier:1
constant:280]];
// Height constraint
[Label1 addConstraint:[NSLayoutConstraint constraintWithItem:Label1
attribute:NSLayoutAttributeHeight
relatedBy:NSLayoutRelationEqual
toItem:nil
attribute: NSLayoutAttributeNotAnAttribute
multiplier:1
constant:21]];
// CenterX constraint
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:self.view
attribute:NSLayoutAttributeCenterX
relatedBy:NSLayoutRelationEqual
toItem:Label1
attribute: NSLayoutAttributeCenterX
multiplier:1
constant:0]];
// Top constraint
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:Label1
attribute:NSLayoutAttributeTop
relatedBy:NSLayoutRelationEqual
toItem:self.topLayoutGuide
attribute: NSLayoutAttributeBottom
multiplier:1
constant:40]];
// label2
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:Label1
attribute:NSLayoutAttributeLeading
relatedBy:NSLayoutRelationEqual
toItem:Label2
attribute: NSLayoutAttributeLeading
multiplier:1
constant:0]];
// label2.Height = label1.Height
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:Label1
attribute:NSLayoutAttributeHeight
relatedBy:NSLayoutRelationEqual
toItem:Label2
attribute: NSLayoutAttributeHeight
multiplier:1
constant:0]];
// label2.width = label1.width
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:Label1
attribute:NSLayoutAttributeWidth
relatedBy:NSLayoutRelationEqual
toItem:Label2
attribute: NSLayoutAttributeWidth
multiplier:1
constant:0]];
// label2.Top
[self.view addConstraint:[NSLayoutConstraint constraintWithItem:Label2
attribute:NSLayoutAttributeTop
relatedBy:NSLayoutRelationEqual
toItem:Label1
attribute: NSLayoutAttributeBottom
multiplier:1
constant:34]];
Result Screen
结果画面
回答by Khushal iOS
i try this method to change height as text length in your label.
我尝试使用此方法将高度更改为标签中的文本长度。
put viewdidload
把viewdidload
[yourlabel setNumberOfLines:0];
CGRect mainframe = _lbl_board.frame;
mainframe.size.height = [self getLabelHeight:yourlabel];
yourlabel.frame = mainframe;
method
方法
- (CGFloat)getLabelHeight:(UILabel*)label
{
CGSize constraint = CGSizeMake(label.frame.size.width, CGFLOAT_MAX);
CGSize size;
NSStringDrawingContext *context = [[NSStringDrawingContext alloc] init];
CGSize boundingBox = [label.text boundingRectWithSize:constraint
options:NSStringDrawingUsesLineFragmentOrigin
attributes:@{NSFontAttributeName:label.font}
context:context].size;
size = CGSizeMake(ceil(boundingBox.width), ceil(boundingBox.height));
return size.height;
}
回答by Beno?t
In Swift 3 : (just replace .Height by .height and .Equal by .equal)
在 Swift 3 中：（只需将 .Height 替换为 .height，将 .Equal 替换为 .equal）
self.addConstraint(NSLayoutConstraint(item: self, attribute: .height, relatedBy: .equal, toItem: nil, attribute: .notAnAttribute, multiplier: 1, constant: 35))
