Android 使用Visual Studio从Xamarin中的活动获取对象结果

我想通过Visual Studio 2015从Xamarin中的子活动接收一个对象：

[Serializable]
class MyObj
{
    public string value { get; }

    public MyObj(string v)
    {
        value = v;
    }
} 

儿童活动

Intent myIntent = new Intent (this, typeof(FirstActivity));
MyObj obj = new MyObj("message");
myIntent.PutExtra ("obj", obj);                                        // cannot convert "obj" to Bundle
SetResult (Result.Ok, myIntent);
Finish();

protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)
{
    base.OnActivityResult(requestCode, resultCode, data);
    if (requestCode == 0)
        if (resultCode == Result.Ok) {
            var helloLabel = FindViewById<TextView> (Resource.Id.helloLabel);
            MyObj obj = data.GetSerializableExtra("obj") as MyObj;
            helloLabel.Text = obj.Text.ToString();
        }
    }
}

FirstActivity

Intent myIntent = new Intent (this, typeof(FirstActivity));
MyObj obj = new MyObj("message");
myIntent.PutExtra ("obj", obj);                                        // cannot convert "obj" to Bundle
SetResult (Result.Ok, myIntent);
Finish();

protected override void OnActivityResult(int requestCode, Result resultCode, Intent data)
{
    base.OnActivityResult(requestCode, resultCode, data);
    if (requestCode == 0)
        if (resultCode == Result.Ok) {
            var helloLabel = FindViewById<TextView> (Resource.Id.helloLabel);
            MyObj obj = data.GetSerializableExtra("obj") as MyObj;
            helloLabel.Text = obj.Text.ToString();
        }
    }
}

---

我想得到一些建议。我是Xamarin的新手，正在使用Visual Studio 2015传递复杂对象有点棘手。您可以使用库，例如在发送之前序列化为字符串，然后在另一端反序列化

myIntent.PutExtra ("obj", JsonConvert.SerializeObject(obj));

//在您的接收活动中，

OnActivityResult

var objectAsString = intent.GetStringExtra("obj")
var result = JsonConvert.DeserializeObject<MyObject>(objectAsString)

var objectAsString=intent.GetStringExtra（“obj”）
var result=JsonConvert.DeserializeObject（objectAsString）

---

很好、简单的解决方案，性能也很好。

我总是选择

Parcelable

。非常快！（快10倍）

以下是如何在Xamarin中实现它：

public class MyObj : Java.Lang.Object, IParcelable
{
    public string Value { get; set; }

    public MyObj()
    {
    }

    private MyObj(Parcel parcel)
    {
        // read your values in order
        Value = parcel.ReadString();
    }

    public void WriteToParcel(Parcel dest, ParcelableWriteFlags flags)
    {
        // read your values in order
        dest.WriteString(Value);
    }

    // -- stuff below here is needed from the parcel interfaces/mechanism --

    [ExportField("CREATOR")]
    public static MyObjCreator InitializeCreator()
    {
        return new MyObjCreator();
    }

    public class MyObjCreator : Java.Lang.Object, IParcelableCreator
    {
        public Java.Lang.Object CreateFromParcel(Parcel source)
        {
            return new MyObj(source);
        }

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

    public int DescribeContents()
    {
        return 0;
    }
}

SetResult

Intent myIntent = new Intent(this, typeof(FirstActivity));
MyObj obj = new MyObj {Value = "Hello"};
myIntent.PutExtra("obj", obj);
SetResult(Result.Ok, myIntent);
Finish();

var x = (MyObj)data.GetParcelableExtra("obj");

OnActivityResult

Intent myIntent = new Intent(this, typeof(FirstActivity));
MyObj obj = new MyObj {Value = "Hello"};
myIntent.PutExtra("obj", obj);
SetResult(Result.Ok, myIntent);
Finish();

var x = (MyObj)data.GetParcelableExtra("obj");

---

我怎样才能取回这个东西？