DataContractSerializer.IsStartObject 方法
定义
确定是否将读取器定位在可反序列化的对象上。Determines whether the reader is positioned on an object that can be deserialized.
重载
| IsStartObject(XmlReader) |
确定是否将 XmlReader 定位在可反序列化的对象上。Determines whether the XmlReader is positioned on an object that can be deserialized. |
| IsStartObject(XmlDictionaryReader) |
确定是否将 XmlDictionaryReader 定位在可反序列化的对象上。Determines whether the XmlDictionaryReader is positioned on an object that can be deserialized. |
IsStartObject(XmlReader)
public:
override bool IsStartObject(System::Xml::XmlReader ^ reader);
public override bool IsStartObject (System.Xml.XmlReader reader);
override this.IsStartObject : System.Xml.XmlReader -> bool
Public Overrides Function IsStartObject (reader As XmlReader) As Boolean
参数
返回
如果读取器位于要读取的流的开始元素处,则为 true;否则为 false。true if the reader is at the start element of the stream to read; otherwise, false.
适用于
IsStartObject(XmlDictionaryReader)
确定是否将 XmlDictionaryReader 定位在可反序列化的对象上。Determines whether the XmlDictionaryReader is positioned on an object that can be deserialized.
public:
override bool IsStartObject(System::Xml::XmlDictionaryReader ^ reader);
public override bool IsStartObject (System.Xml.XmlDictionaryReader reader);
override this.IsStartObject : System.Xml.XmlDictionaryReader -> bool
Public Overrides Function IsStartObject (reader As XmlDictionaryReader) As Boolean
参数
- reader
- XmlDictionaryReader
一个用于读取 XML 流的 XmlDictionaryReader。An XmlDictionaryReader used to read the XML stream.
返回
如果读取器位于要读取的流的开始元素处,则为 true;否则为 false。true if the reader is at the start element of the stream to read; otherwise, false.
示例
下面的示例使用 IsStartObject 属性来确定是否已找到数据的开始位置。The following example uses the IsStartObject property to determine whether the start of the data has been found.
public static void ReadObjectData(string path)
{
// Create the reader.
FileStream fs = new FileStream(path, FileMode.Open);
XmlDictionaryReader reader =
XmlDictionaryReader.CreateTextReader(fs, new XmlDictionaryReaderQuotas());
// Create the DataContractSerializer specifying the type,
// root and namespace to use. The root value corresponds
// to the DataContract.Name value, and the namespace value
// corresponds to the DataContract.Namespace value.
DataContractSerializer ser =
new DataContractSerializer(typeof(Person),
"Customer", @"http://www.contoso.com");
// Test if the serializer is on the start of the
// object data. If so, read the data and write it
// to the console.
while (reader.Read())
{
if (ser.IsStartObject(reader))
{
Console.WriteLine("Found the element");
Person p = (Person)ser.ReadObject(reader);
Console.WriteLine("{0} {1} id:{2}",
p.FirstName, p.LastName, p.ID);
}
Console.WriteLine(reader.Name);
break;
}
fs.Flush();
fs.Close();
}
Public Shared Sub ReadObjectData(ByVal path As String)
' Create the reader.
Dim fs As New FileStream(path, FileMode.Open)
Dim reader As XmlDictionaryReader = _
XmlDictionaryReader.CreateTextReader(fs, New XmlDictionaryReaderQuotas())
' Create the DataContractSerializer specifying the type,
' root and namespace to use. The root value corresponds
' to the DataContract.Name value, and the namespace value
' corresponds to the DataContract.Namespace value.
Dim ser As New DataContractSerializer(GetType(Person), _
"Customer", "http://www.contoso.com")
' Test if the serializer is on the start of the
' object data. If so, read the data and write it
' to the console.
While reader.Read()
If ser.IsStartObject(reader) Then
Console.WriteLine("Found the element")
Dim p As Person = CType(ser.ReadObject(reader), Person)
Console.WriteLine("{0} {1} id:{2}", p.FirstName, p.LastName, p.ID)
End If
Console.WriteLine(reader.Name)
End While
fs.Flush()
fs.Close()
End Sub
注解
IsStartObject 通过检查其是否定位在 XML 元素上,确定其能否读取某个对象。The IsStartObject determines whether it can read an object by checking that it is positioned on an XML element. 它还检查读取器所在的 XML 元素的名称和命名空间,并将这些值与预期的名称和命名空间进行比较。It also examines the name and namespace of the XML element that the reader is positioned at and compares the values to the expected name and namespace. 可利用以下各项设置预期的名称和命名空间:传入构造函数的类型的数据协定名称和命名空间,或者是传入构造函数的 rootName 和 rootNamespace 值(如果有)。The expected name and namespace can be set with the following: the data contract name and namespace of the type passed into the constructor, or the rootName and rootNamespace values passed into the constructor (if present).