KnownAssemblyAttribute
Sampel KnownAssemblyAttribute menunjukkan bagaimana proses serialisasi dan deserialisasi dapat disesuaikan menggunakan kelas DataContractResolver. Sampel ini menunjukkan cara menambahkan jenis yang diketahui secara dinamis selama serialisasi dan deserialisasi.
Detail Sampel
Sampel ini terdiri dari empat proyek. Salah satunya sesuai dengan layanan, yang akan dihosting oleh IIS, yang menentukan kontrak layanan berikut.
// Definition of a service contract.
[ServiceContract(Namespace = "http://Microsoft.Samples.KAA")]
[KnownAssembly("Types")]
public interface IDataContractCalculator
{
[OperationContract]
ComplexNumber Add(ComplexNumber n1, ComplexNumber n2);
[OperationContract]
ComplexNumber Subtract(ComplexNumber n1, ComplexNumber n2);
[OperationContract]
ComplexNumber Multiply(ComplexNumber n1, ComplexNumber n2);
[OperationContract]
ComplexNumber Divide(ComplexNumber n1, ComplexNumber n2);
[OperationContract]
List<ComplexNumber> CombineLists(List<ComplexNumber> list1, List<ComplexNumber> list2);
}
Kontrak layanan diimplementasikan seperti yang ditunjukkan dalam contoh berikut.
// Service class that implements the service contract.
public class DataContractCalculatorService : IDataContractCalculator
{
public ComplexNumber Add(ComplexNumber n1, ComplexNumber n2)
{
return new ComplexNumberWithMagnitude(n1.Real + n2.Real, n1.Imaginary + n2.Imaginary);
}
public ComplexNumber Subtract(ComplexNumber n1, ComplexNumber n2)
{
return new ComplexNumberWithMagnitude(n1.Real - n2.Real, n1.Imaginary - n2.Imaginary);
}
public ComplexNumber Multiply(ComplexNumber n1, ComplexNumber n2)
{
double real1 = n1.Real * n2.Real;
double imaginary1 = n1.Real * n2.Imaginary;
double imaginary2 = n2.Real * n1.Imaginary;
double real2 = n1.Imaginary * n2.Imaginary * -1;
return new ComplexNumber(real1 + real2, imaginary1 + imaginary2);
}
public ComplexNumber Divide(ComplexNumber n1, ComplexNumber n2)
{
ComplexNumber conjugate = new ComplexNumber(n2.Real, -1 * n2.Imaginary);
ComplexNumber numerator = Multiply(n1, conjugate);
ComplexNumber denominator = Multiply(n2, conjugate);
return new ComplexNumber(numerator.Real / denominator.Real, numerator.Imaginary);
}
public List<ComplexNumber> CombineLists(List<ComplexNumber> list1, List<ComplexNumber> list2)
{
List<ComplexNumber> result = new List<ComplexNumber>();
result.AddRange(list1);
result.AddRange(list2);
return result;
}
}
Proyek lain sesuai dengan klien, yang berkomunikasi dengan server dan memanggil metode yang dieksposnya. Definisi klien ditunjukkan pada contoh berikut.
// Client implementation code.
class Client
{
static void Main()
{
// Create a channel.
EndpointAddress address = new EndpointAddress("http://localhost/servicemodelsamples/service.svc/IDataContractCalculator");
BasicHttpBinding binding = new BasicHttpBinding();
ChannelFactory<IDataContractCalculator> factory = new ChannelFactory<IDataContractCalculator>(binding, address);
IDataContractCalculator channel = factory.CreateChannel();
// Call the Add service operation.
ComplexNumber value1 = new ComplexNumber(1, 2);
ComplexNumber value2 = new ComplexNumberWithMagnitude(3, 4);
ComplexNumber result = channel.Add(value1, value2);
Console.WriteLine("Add({0} + {1}i, {2} + {3}i) = {4} + {5}i",
value1.Real, value1.Imaginary, value2.Real, value2.Imaginary, result.Real, result.Imaginary);
if (result is ComplexNumberWithMagnitude)
{
Console.WriteLine("Magnitude: {0}", ((ComplexNumberWithMagnitude)result).Magnitude);
}
else
{
Console.WriteLine("No magnitude was sent from the service");
}
Console.WriteLine();
// Call the Subtract service operation.
value1 = new ComplexNumber(1, 2);
value2 = new ComplexNumber(3, 4);
result = channel.Subtract(value1, value2);
Console.WriteLine("Subtract({0} + {1}i, {2} + {3}i) = {4} + {5}i",
value1.Real, value1.Imaginary, value2.Real, value2.Imaginary, result.Real, result.Imaginary);
if (result is ComplexNumberWithMagnitude)
{
Console.WriteLine("Magnitude: {0}", ((ComplexNumberWithMagnitude)result).Magnitude);
}
else
{
Console.WriteLine("No magnitude was sent from the service");
}
Console.WriteLine();
// Call the Multiply service operation.
value1 = new ComplexNumber(2, 3);
value2 = new ComplexNumber(4, 7);
result = channel.Multiply(value1, value2);
Console.WriteLine("Multiply({0} + {1}i, {2} + {3}i) = {4} + {5}i",
value1.Real, value1.Imaginary, value2.Real, value2.Imaginary, result.Real, result.Imaginary);
if (result is ComplexNumberWithMagnitude)
{
Console.WriteLine("Magnitude: {0}", ((ComplexNumberWithMagnitude)result).Magnitude);
}
else
{
Console.WriteLine("No magnitude was sent from the service");
}
Console.WriteLine();
// Call the Divide service operation.
value1 = new ComplexNumber(3, 7);
value2 = new ComplexNumber(5, -2);
result = channel.Divide(value1, value2);
Console.WriteLine("Divide({0} + {1}i, {2} + {3}i) = {4} + {5}i",
value1.Real, value1.Imaginary, value2.Real, value2.Imaginary, result.Real, result.Imaginary);
if (result is ComplexNumberWithMagnitude)
{
Console.WriteLine("Magnitude: {0}", ((ComplexNumberWithMagnitude)result).Magnitude);
}
else
{
Console.WriteLine("No magnitude was sent from the service");
}
Console.WriteLine();
// Call the CombineLists service operation.
List<ComplexNumber> list1 = new List<ComplexNumber>();
List<ComplexNumber> list2 = new List<ComplexNumber>();
list1.Add(new ComplexNumber(1, 1));
list1.Add(new ComplexNumber(2, 2));
list1.Add(new ComplexNumberWithMagnitude(3, 3));
list1.Add(new ComplexNumberWithMagnitude(4, 4));
List<ComplexNumber> listResult = channel.CombineLists(list1, list2);
Console.WriteLine("Lists combined:");
foreach (ComplexNumber n in listResult)
{
Console.WriteLine("{0} + {1}i", n.Real, n.Imaginary);
}
Console.WriteLine();
// Close the channel
((IChannel)channel).Close();
Console.WriteLine();
Console.WriteLine("Press <ENTER> to terminate client.");
Console.ReadLine();
}
}
Definisi kontrak layanan ditandai dengan atribut KnownAssembly. Atribut ini berisi nama pustaka jenis, yang semuanya diketahui saat dijalankan oleh layanan dan klien.
Atribut KnownAssembly mengimplementasikan IContractBehavior untuk menentukan DataContractSerializer dengan DataContractResolver yang ditentukan untuk setiap perilaku operasi. DataContractResolver merefleksikan assembly saat dibuat, dan membuat kamus dengan pemetaan antara jenis dan nama yang akan digunakan saat membuat serialisasi dan deserialisasi jenis yang berbeda. Dengan cara itu, jenis ResolveType dan ResolveName harus mencari data yang diperlukan dalam kamus.
DataContractResolver yang ditentukan untuk sampel ini ditunjukkan pada contoh berikut.
public class MyDataContractResolver : DataContractResolver
{
Dictionary<string, XmlDictionaryString> dictionary = new Dictionary<string, XmlDictionaryString>();
Assembly assembly;
public MyDataContractResolver(string assemblyName)
{
this.KnownTypes = new List<Type>();
assembly = Assembly.Load(new AssemblyName(assemblyName));
foreach (Type type in assembly.GetTypes())
{
bool knownTypeFound = false;
System.Attribute[] attrs = System.Attribute.GetCustomAttributes(type);
if (attrs.Length != 0)
{
foreach (System.Attribute attr in attrs)
{
if (attr is KnownTypeAttribute)
{
Type t = ((KnownTypeAttribute)attr).Type;
if (this.KnownTypes.IndexOf(t) < 0)
{
this.KnownTypes.Add(t);
}
knownTypeFound = true;
}
}
}
if (!knownTypeFound)
{
string name = type.Name;
string namesp = type.Namespace;
if (!dictionary.ContainsKey(name))
{
dictionary.Add(name, new XmlDictionaryString(XmlDictionary.Empty, name, 0));
}
if (!dictionary.ContainsKey(namesp))
{
dictionary.Add(namesp, new XmlDictionaryString(XmlDictionary.Empty, namesp, 0));
}
}
}
}
public IList<Type> KnownTypes
{
get; set;
}
// Used at deserialization
// Allows users to map xsi:type name to any Type
public override Type ResolveName(string typeName, string typeNamespace, DataContractResolver knownTypeResolver)
{
XmlDictionaryString tName;
XmlDictionaryString tNamespace;
if (dictionary.TryGetValue(typeName, out tName) && dictionary.TryGetValue(typeNamespace, out tNamespace))
{
return this.assembly.GetType(tNamespace.Value + "." + tName.Value);
}
else
{
return knownTypeResolver.ResolveName(typeName, typeNamespace, null);
}
}
// Used at serialization
// Maps any Type to a new xsi:type representation
public override void ResolveType(Type dataContractType, DataContractResolver knownTypeResolver, out XmlDictionaryString typeName, out XmlDictionaryString typeNamespace)
{
knownTypeResolver.ResolveType(dataContractType, null, out typeName, out typeNamespace);
if (typeName == null || typeNamespace == null)
{
typeName = new XmlDictionaryString(XmlDictionary.Empty, dataContractType.Name, 0);
typeNamespace = new XmlDictionaryString(XmlDictionary.Empty, dataContractType.Namespace, 0);
}
}
}
Pustaka jenis yang digunakan dalam sampel ini ditampilkan dalam contoh berikut.
[DataContract]
public class ComplexNumber
{
[DataMember]
private double real;
[DataMember]
private double imaginary;
public ComplexNumber(double r1, double i1)
{
this.Real = r1;
this.Imaginary = i1;
}
public double Real
{
get { return real; }
set { real = value; }
}
public double Imaginary
{
get { return imaginary; }
set { imaginary = value; }
}
}
[DataContract]
public class ComplexNumberWithMagnitude : ComplexNumber
{
public ComplexNumberWithMagnitude(double real, double imaginary) : base(real, imaginary) { }
[DataMember]
public double Magnitude
{
get { return Math.Sqrt(Imaginary * Imaginary + Real * Real); }
set { }
}
}
Perhatikan bahwa ComplexNumber tidak perlu secara statis mengetahui jenis ComplexNumberWithMagnitude, karena diketahui pada waktu eksekusi.
Ketika sampel dibangun dan dieksekusi, ini adalah output yang diharapkan yang diperoleh di komputer klien:
Add(1 + 2i, 3 + 4i) = 4 + 6i
Magnitude: 7.21110255092798
Subtract(1 + 2i, 3 + 4i) = -2 + -2i
Magnitude: 2.82842712474619
Multiply(2 + 3i, 4 + 7i) = -13 + 26i
No magnitude was sent from the service
Divide(3 + 7i, 5 + -2i) = 0.0344827586206897 + 41i
No magnitude was sent from the service
Lists combined:
1 + 1i
2 + 2i
3 + 3i
4 + 4i
Untuk menyiapkan, menjalankan, dan membangun sampel
Klik kanan solusi KnownAssemblyAttribute dan pilih Properti.
Di Properti Umum, pilih Proyek Startup, lalu klik Beberapa proyek startup.
Tambahkan tindakan Mulai ke proyek Layanan dan Klien.
Klik OK, dan tekan F5 untuk menjalankan sampel.
Jika aplikasi tidak berjalan dengan baik, ikuti langkah-langkah berikut untuk memastikan lingkungan Anda telah disiapkan dengan benar:
Pastikan Anda telah melakukan Prosedur Penyiapan Satu Kali untuk Sampel WCF.
Untuk membangun solusi, ikuti instruksi dalam Membangun Sampel Windows Communication Foundation.
Untuk menjalankan sampel dalam konfigurasi satu atau lintas komputer, ikuti instruksi pada Menjalankan Sampel WCF.