Android Bundle Parcelable 数据传递：解决 GetParcelable(string) 过时问题

// 假设 User 是一个实现了 IParcelable 接口的自定义类
User MyUser = new User("John Doe", "john@example.com", /* ... 其他属性 ... */);

Intent intent = new Intent(this, typeof(Menu));
Bundle bundlee = new Bundle();
// 将 User 对象放入 Bundle
bundlee.PutParcelable("MyUser", MyUser); 
intent.PutExtra("TheBundle", bundlee);
StartActivity(intent);

// 在目标 Activity 中获取 Bundle
Bundle bundlee = Intent.GetBundleExtra("TheBundle");

User MyUser = new User("", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "");
// 此行代码会触发过时警告/错误
MyUser = bundlee.GetParcelable("MyUser") as User; 

// 在目标 Activity 中获取 Bundle
Bundle bundlee = Intent.GetBundleExtra("TheBundle");

// 确保 bundlee 不为 null
if (bundlee != null)
{
    // 使用新的类型安全方法获取 Parcelable 对象
    // 方法一：通过 typeof(User) 获取类型信息
    User MyUser = bundlee.GetParcelable("MyUser", Java.Lang.Class.FromType(typeof(User))) as User;

    // 或者，如果 MyUser 实例已经存在，也可以通过 MyUser.GetType() 获取类型信息
    // User MyUser = new User("", "", "", /* ... */); // 如果需要默认初始化
    // MyUser = bundlee.GetParcelable("MyUser", Java.Lang.Class.FromType(MyUser.GetType())) as User;

    if (MyUser != null)
    {
        // 成功获取到 User 对象，可以继续操作
        Console.WriteLine($"Received User: {MyUser.Name}, {MyUser.Email}");
    }
    else
    {
        Console.WriteLine("Failed to retrieve MyUser from Bundle or MyUser is null.");
    }
}
else
{
    Console.WriteLine("Bundle is null.");
}

// 假设 User 是一个实现了 IParcelable 接口的自定义类
public class User : Java.Lang.Object, IParcelable
{
    public string Name { get; set; }
    public string Email { get; set; }
    // ... 其他属性

    public User(string name, string email, /* ... */)
    {
        Name = name;
        Email = email;
        // ...
    }

    // 实现 IParcelable 接口所需的方法
    public int DescribeContents() => 0;

    public void WriteToParcel(Parcel dest, ParcelFlags flags)
    {
        dest.WriteString(Name);
        dest.WriteString(Email);
        // ... 写入其他属性
    }

    public static readonly GenericParcelableCreator<User> Creator = new GenericParcelableCreator<User>((parcel) => new User(parcel));

    protected User(Parcel parcel)
    {
        Name = parcel.ReadString();
        Email = parcel.ReadString();
        // ... 读取其他属性
    }
}

// 辅助类，用于实现 Parcelable.Creator
public class GenericParcelableCreator<T> : Java.Lang.Object, IParcelableCreator where T : Java.Lang.Object, IParcelable
{
    private readonly Func<Parcel, T> _createFromParcel;

    public GenericParcelableCreator(Func<Parcel, T> createFromParcel)
    {
        _createFromParcel = createFromParcel;
    }

    public Java.Lang.Object CreateFromParcel(Parcel source)
    {
        return _createFromParcel(source);
    }

    public Java.Lang.Object[] NewArray(int size)
    {
        return new T[size];
    }
}

// Activity A (发送数据)
public class ActivityA : Activity
{
    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        SetContentView(Resource.Layout.ActivityA); // 假设有布局

        Button sendButton = FindViewById<Button>(Resource.Id.sendButton); // 假设有按钮
        sendButton.Click += (sender, e) =>
        {
            User myUserToSend = new User("Alice Smith", "alice@example.com");

            Intent intent = new Intent(this, typeof(ActivityB));
            Bundle bundle = new Bundle();
            bundle.PutParcelable("MyUser", myUserToSend); // PutParcelable 仍然可用
            intent.PutExtra("TheBundle", bundle);
            StartActivity(intent);
        };
    }
}

// Activity B (接收数据)
public class ActivityB : Activity
{
    protected override void OnCreate(Bundle savedInstanceState)
    {
        base.OnCreate(savedInstanceState);
        SetContentView(Resource.Layout.ActivityB); // 假设有布局

        TextView receivedUserTextView = FindViewById<TextView>(Resource.Id.receivedUserTextView); // 假设有文本视图

        Bundle bundle = Intent.GetBundleExtra("TheBundle");

        if (bundle != null)
        {
            // 关键：使用类型安全的 GetParcelable 方法
            User receivedUser = bundle.GetParcelable("MyUser", Java.Lang.Class.FromType(typeof(User))) as User;

            if (receivedUser != null)
            {
                receivedUserTextView.Text = $"Received User: Name={receivedUser.Name}, Email={receivedUser.Email}";
            }
            else
            {
                receivedUserTextView.Text = "Failed to receive user data.";
            }
        }
        else
        {
            receivedUserTextView.Text = "No bundle received.";
        }
    }
}