如何在 Xamarin Forms 中使用 StreamReader 填写表单

Question

我正在 Xamarin Forms 中创建一个项目，允许用户输入他们的姓名、用户名、密码，并使用步进器告诉他们年龄，并使用开关来识别用户是否是学生。然后用户可以点击保存，信息将通过 StreamWriter 保存到一个文件中。然后用户将能够点击“加载”，他们所有保存的信息将自动填充输入框、年龄值和学生“真或假”开关。我在 MainPage.xaml.cs class 中遇到问题，无法加载保存的信息以填充字段。我已将 MainPage.xaml 中的控件名称绑定到 EntryFields class 中的属性值。这是我第一次使用 Xamarin Forms，我被卡住了。请帮忙：）这是我在遇到问题之前保存的方法所拥有的：

        {
            List<string> data = new List<string>();
            bool stepValue;
            int ageValue;
            //Read data from file
            if (File.Exists(_fileName))
            {
                using (var reader = new StreamReader(_fileName))
                {
                    string line;
                    while ((line = reader.ReadLine()) != null)
                    {
                        data.Add(line);
                    }
                    
                    for(int i = 0; i < data.Count; i++)
                    {
                        if (data[4] == "true")
                        {
                            stepValue = true;
                        }
                        else if (data[4] == "false")
                        {
                            stepValue = false;
                        }
                        ageValue = Int32.Parse(data[3]);
                        //This is where I am stuck. I want to add each item to my list of EntryFields
                        //but I am not sure how since they're all different values.
                    }
                    

                }
            }
            else
            {
                DisplayAlert("Error", "Unable to load. Fill out required information and select SAVE.", "Go Back");
            }


        }

这是我的 EntryFields class，看起来像这样：

    {
        public bool TrueOrFalse { get; set; }

        public string Name { get; set; }
        
        public string Username { get; set; }

        public string Password { get; set; }

        public int Age { get; set; }

        public EntryFields(string name, string username, string password, int age, string student)
        {
            Name = name;
            Username = username;
            Password = password;
            Age = age;
            if (student.ToLower() == "true")
            {
                TrueOrFalse = true;
            }
            else if(student.ToLower() == "false")
            {
                TrueOrFalse = false;
            }
        }
    }

最后，所以我们都在看同一件事，这是我的 MainPage.xaml class:

<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             x:Class="MorganHall_CE01.MainPage">

    <StackLayout IsVisible="True">
        <Frame BackgroundColor="#2196F3" Padding="24" CornerRadius="0">
            <Label Text="Code Exercise 1" HorizontalTextAlignment="Center" TextColor="White" FontSize="36"/>
        </Frame>
        <Entry x:Name="nameEntry" Placeholder="Enter Name Here" HorizontalOptions="FillAndExpand" HorizontalTextAlignment="Center" Text="{Binding Path=Name}" TextColor="#514E4E" />
        <Entry x:Name="usernameEntry" Placeholder="Enter Username Here" HorizontalOptions="FillAndExpand" HorizontalTextAlignment="Center" Text="{Binding Username}" TextColor="#514E4E" />
        <Entry x:Name="passwordEntry" Placeholder="Enter Password Here" HorizontalOptions="FillAndExpand" HorizontalTextAlignment="Center" Text="{Binding Password}" IsPassword="True" TextColor="#514E4E" />
        <StackLayout Orientation="Horizontal" Margin="10">
            <Label x:Name="ageLabel" Text="Age: " HorizontalTextAlignment="Start" HorizontalOptions="FillAndExpand" FontAttributes="Bold" TextColor="#000000" />
            <Stepper x:Name="ageStepper" Minimum="0" Maximum="100" Increment="1" Margin="50,0" Value="{Binding Age}" />
        </StackLayout>
        <StackLayout Orientation="Horizontal">
            <Label x:Name="studentLabel" Text="Enrolled Student: " HorizontalTextAlignment="Start" HorizontalOptions="FillAndExpand" FontAttributes="Bold" TextColor="#000000" />
            <Switch x:Name="studentSwitch" IsToggled="{Binding TrueOrFalse}" Margin="50,0" OnColor="#60E848" ThumbColor="#484453" />
        </StackLayout>
        <StackLayout Orientation="Horizontal">
            <Button x:Name="loadData" Text="Load" HorizontalOptions="EndAndExpand" FontAttributes="Bold" BackgroundColor="#138A83" TextColor="#FDFAFA" />
            <Button x:Name="saveData" Text="Save" HorizontalOptions="StartAndExpand" FontAttributes="Bold" BackgroundColor="#075D7F" TextColor="#FBF8F8" />
        </StackLayout>
    </StackLayout>
</ContentPage>

在 MainPage.xaml.cs class 中，我有一个 EntryFields 列表，如下所示： private List<EntryFields> entries = new List<EntryFields>();

请告诉我有更好更简单的方法来加载保存的信息。我都糊涂了。提前致谢！ :)

Answer 1

像这样的东西应该有用

var entries = new EntryFields();

// this will read all the file data into a string array
var data = File.ReadAllLines(_fileName);

// you will need to be sure the order matches the order you saved in
entries.Name = data[1];
entries.Username = data[2];
entries.Password = data[3];
entries.Age = int.Parse(data[4]);

// set the binding context of the page
this.BindingContext = entries;

如何在 Xamarin Forms 中使用 StreamReader 填写表单

How to fill out a form from StreamReader in Xamarin Forms

c#

streamreader

xamarin.android

xamarin.forms