Question

我想以编程方式创建一个UITextField并相应地设置其样式。我创建

let userName = UITextField(frame: CGRect(x: 60, y: 60, width: 200.00, height: 200));
userName.placeholder = "Username";
userName.textAlignment = NSTextAlignment.left;
userName.font = UIFont(name: "SpaceGrotesk-Light", size: 20.0);
userName.setBottomBorder()
view.addSubview(userName)
userName.translatesAutoresizingMaskIntoConstraints = false;
userName.leftAnchor.constraint(equalTo: view.leftAnchor,constant: 70).isActive = true;
userName.topAnchor.constraint(equalTo: WelcomeText.topAnchor,constant: 70).isActive = true;

这有效，但是字段的宽度与占位符相同，并且不会增加，但是如果您开始输入，则字段的宽度会根据输入的文本而增加。
我是初学者，不知道为什么会这样。
我试图增加宽度，但没有运气。

let userName = UITextField(frame: CGRect(x: 60, y: 60, width: 400.00, height: 200));

Answer 1

首先，最好在变量名的开头使用小写字母-而不是

let UserName = UITextField(...)

使用

let userName = UITextField(...)

但是，这与上浆无关。

您似乎正在尝试使用自动布局“混合并匹配”显式帧。使用另一个。

像这样尝试：

// we'll use constraints, so no need to set a frame
let UserName = UITextField();
UserName.placeholder = "Username";
UserName.textAlignment = NSTextAlignment.left;
UserName.font = UIFont(name: "SpaceGrotesk-Light", size: 20.0);
UserName.setBottomBorder()
view.addSubview(UserName)

// this says "use auto-layout constraints"
UserName.translatesAutoresizingMaskIntoConstraints = false;

UserName.leftAnchor.constraint(equalTo: view.leftAnchor,constant: 70).isActive = true;
UserName.topAnchor.constraint(equalTo: WelcomeText.topAnchor,constant: 70).isActive = true;

// now, set your explicit width
UserName.widthAnchor.constraint(equalToConstant: 200.0).isActive = true

或者，如果您希望它根据其超级视图的宽度伸展：

// you have 70-pts padding from the left, so constrain to 70-pts padding from the right
// note that it should be negative (because you want it *from* the right-edge)
UserName.rightAnchor.constraint(equalTo: view.rightAnchor, constant: -70).isActive = true

Answer 2

创建视图并配置约束后，您可以尝试使用updateConstraints或layoutIfNeeded函数

userName.updateConstraints()
or
userName.layoutIfNeeded()

UITextField不根据指定的宽度缩放

2 个答案: