点击登录按钮时如何更改视图？

Question

@State private var email = ""
@State private var password = ""
@EnvironmentObject var session:SessionStore
@EnvironmentObject var viewRouter:ViewRouter

func signIn(email: email, password: password) { (result, error) in
    if let error = error {
        self.error = error.localizedDescription}
    else {
        self.email = ""
        self.password = ""
    }
}


var body: some View {
    
    if (error != "") {
        Text(error)
    }
    
    Button(action: {
        signIn()
        viewRouter.currentPage = .entrypage
        
    }, label: {
        Text("Sign In")
    })
    
}

当我点击登录按钮视图更改时，无论 email 和密码是否为空。 我想在 email 或密码为空时设置条件以显示错误，否则登录并更改视图。

Answer 1

有多种解决方案。 这是一个：如果没有电子邮件/密码，您可以在按钮上使用三元运算符来防止使用该按钮：.disabled(self.email == "" || self.password == "" )

针对您的评论编辑的答案：

Button(action: {
    if self.email == "" || self.password ==  "" {
       self.error = "Please enter your credentials first."
    }
    else {
       signIn()
       viewRouter.currentPage = .entrypage
    }
    
}, label: {
    Text("Sign In")
})