Android（五十二）：GetSharedPreferences 数据存储与访问

private ISharedPreferences _sharedPreferences;

_sharedPreferences = GetSharedPreferences("loginInfo", FileCreationMode.Private);

var username = FindViewById(Resource.Id.username);
var password = FindViewById(Resource.Id.password);
var loginBtn = FindViewById(Resource.Id.login_btn);
var userInfoBtn = FindViewById(Resource.Id.user_info_btn);

if (loginBtn != null)
    loginBtn.Click += delegate
    {
        var loginInfo = new Dictionary
        {
            { "username", username == null ? "" : username.Text },
            { "password", password == null ? "" : password.Text }
        };
        SaveLoginInfo(loginInfo);
    };

if (userInfoBtn != null)
    userInfoBtn.Click += delegate
    {
        var loginInfo = GetLoginInfo();
        if (username != null) username.Text = loginInfo["username"];
        if (password != null) password.Text = loginInfo["password"];
        Toast.MakeText(this, $"{PackageName} --> {loginInfo["username"]} - {loginInfo["password"]}",
            ToastLength.Short)?.Show();
    };

// 保存数据
private void SaveLoginInfo(IReadOnlyDictionary loginInfo)
{
    var edit = _sharedPreferences?.Edit();
    edit?.PutString("username", loginInfo["username"]);
    edit?.PutString("password", loginInfo["password"]);
    edit?.Commit();
    Toast.MakeText(this, $"{PackageName} --> {loginInfo["username"]} - {loginInfo["password"]}",
        ToastLength.Short)?.Show();
}

// 读取数据
private Dictionary GetLoginInfo()
{
    var loginInfo = new Dictionary
    {
        { "username", _sharedPreferences?.GetString("username", "") },
        { "password", _sharedPreferences?.GetString("password", "") }
    };
    return loginInfo;
}