ios - 为什么更改状态变量时界面会抽动？

Question

内容 View :

@State var login: String = ""
@State var password: String = ""
@State var isLoginTextViewActive = false
@State var isPasswordTextViewActive = false

    VStack {
        TextField("Login", text: $login, onEditingChanged: { isEditing in
            print(isEditing)
            self.isLoginTextViewActive = isEditing
            }
        )
        TextField("Password", text: $password)
        HorizontalLine(color: isLoginTextViewActive ? Color.yellow : Color.black, height: CGFloat(1))
        }.frame(width: CGFloat(200), alignment: .center)

行代码:

struct HorizontalLineShape: Shape {
    func path(in rect: CGRect) -> Path {

        let fill = CGRect(x: 0, y: 0, width: rect.size.width, height: rect.size.height)
        var path = Path()
        path.addRoundedRect(in: fill, cornerSize: CGSize(width: 2, height: 2))

        return path
    }
}

struct HorizontalLine: View {
    private var color: Color? = nil
    private var height: CGFloat = 1.0

    init(color: Color, height: CGFloat = 1.0) {
        self.color = color
        self.height = height
    }

    var body: some View {
        HorizontalLineShape().fill(self.color!).frame(minWidth: 0, maxWidth: .infinity, minHeight: height, maxHeight: height)
    }
}

当您在“TextView”之间更改焦点时，它们开始抽搐，就像由于高度变化一样。我检查过，每次调用行初始值设定项时，但我不知道如何处理它。

Answer 1

发生这种情况是因为当前文本字段中的字体大小存在错误。如果您手动设置字体大小(例如 20)，它将按照您想要的方式工作。

var body: some View {
    VStack {
        TextField("Login", text: $login, onEditingChanged: { isEditing in
            print(isEditing)
            self.isLoginTextViewActive = isEditing
        })
        .font(.system(size: 20, weight: .medium, design: .default)) // SET SIZE

        TextField("Password", text: $password)
            .font(.system(size: 20, weight: .medium, design: .default)) // SET SIZE

        Rectangle()
            .frame(height: 1)
            .foregroundColor(isLoginTextViewActive ? Color.yellow : Color.black)
    }.frame(width: CGFloat(200), alignment: .center)
}