编辑代码

ContentView.swift
LoginSwiftUI
Created by Zhifeng Chen on 2020/8/1.
Copyright  2020 Zhifeng Chen. All rights reserved.
import SwiftUI
let lightGrayColor = Color(red: 239.0/255.0, green: 243.0/255.0, blue:244.0/255.0，opacity：1.0)
struct ContentView : Viewí
//保存输入的用户名
@State var userName : String It 
//保存输入的密码
State var passWord : String
//是否需要弹出Alert 窗口
State private var alertFlag : Bool = false
//弹出窗口里面的具体内容
@State private var alertMsg : String =""
var body: some
View
vstackText(”欢迎使用找不同")
.font(.title)//字体大小为标题
·padding()//四周间隔
Divider()
.background(Color(.brown))//背景色为brown
Image("back02")//图片back02.png
.resizable()//允许改变图像尺寸
.frame (width:150, height: 150)//尺寸改为150*150
.cornerRadius(150)//圆角半径 50
vstack {
TextField("请输入用户名"，text: $userName)
.padding()//四周默认间隔
.padding(.leading,10)//前方间隔10
.background(lightGrayColor)// 背景色
.cornerRadius(15)//圆角半径 15
TextField("请输入密码"，text:SpassWord)
.padding()// 四周默认间隔
.padding(.leading,10)//前方间隔10
.background(lightGrayColor)//背景色
.cornerRadius(15)//圆角半径 15
.padding() // 四周默认间隔
Button(action:{
if self.userName == "Zfchen" && self.passWord =="123”
self.alertFlag = true
self.alertMsg="登录成功”
}
else 
self.alertFlag = true
self.alertMsg="登录失败”
}
}，label：{
Text("登录")
.font(.headline)
.foregroundColor(.white)
.frame(width：220, height：60)
.background(Color.green)
.cornerRadius(15.0)
})
.padding()
Spacer()
}
.alert(isPresented: $alertFlag){() ->Alert in
Alert(title: Text("登录提示")， message: Text(self.alertMsg),
dismissButton: ·default(Text("确定")))
}
}
}
struct ContentView Previews: previewProvider{
static var previews: some View{
ContentView()
}
}