DataTable.ReadXmlSchema 方法

参考

定义

命名空间:: System.Data

程序集:: System.Data.Common.dll

程序集:: System.Data.dll

程序集:: netstandard.dll

重要

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将 XML 架构读入 DataTable。

重载

ReadXmlSchema(XmlReader)	使用指定的 XmlReader 将 XML 架构读入 DataTable。
ReadXmlSchema(String)	从指定的文件将 XML 架构读入 DataTable。
ReadXmlSchema(TextReader)	使用指定的 TextReader 将 XML 架构读入 DataTable。
ReadXmlSchema(Stream)	使用指定的流将 XML 架构读入 DataTable。

注解

ReadXmlSchema使用方法创建的DataTable架构。架构包括表、关系和约束定义。

若要将架构写入 XML 文档，请使用 WriteXmlSchema 方法。

XML 架构根据 XSD 标准进行解释。

通常，在 ReadXmlSchema 调用 ReadXml 用于填充的方法之前调用方法 DataTable。

ReadXmlSchema(XmlReader)

Source:: DataTable.cs

Source:: DataTable.cs

Source:: DataTable.cs

使用指定的 XmlReader 将 XML 架构读入 DataTable。

public:
 void ReadXmlSchema(System::Xml::XmlReader ^ reader);

public void ReadXmlSchema (System.Xml.XmlReader? reader);

public void ReadXmlSchema (System.Xml.XmlReader reader);

member this.ReadXmlSchema : System.Xml.XmlReader -> unit

Public Sub ReadXmlSchema (reader As XmlReader)

参数

reader: XmlReader

用于读取架构信息的 XmlReader。

示例

以下控制台应用程序创建一个新的 DataTable，并将该表的架构写入。MemoryStream 然后，该示例创建一个新的 DataTable ，并使用继承自 XmlReader) 作为源的 (从保存的 XML 架构读取其架构XmlTextReader。

private static void DemonstrateReadWriteXMLSchemaWithReader()
{
    DataTable table = CreateTestTable("XmlDemo");
    PrintSchema(table, "Original table");

    // Write the schema to XML in a memory stream.
    System.IO.MemoryStream xmlStream =
        new System.IO.MemoryStream();
    table.WriteXmlSchema(xmlStream);

    // Rewind the memory stream.
    xmlStream.Position = 0;

    DataTable newTable = new DataTable();
    System.Xml.XmlTextReader reader =
        new System.Xml.XmlTextReader(xmlStream);
    newTable.ReadXmlSchema(reader);

    // Print out values in the table.
    PrintSchema(newTable, "New table");
}

private static DataTable CreateTestTable(string tableName)
{
    // Create a test DataTable with two columns and a few rows.
    DataTable table = new DataTable(tableName);
    DataColumn column = new DataColumn("id", typeof(System.Int32));
    column.AutoIncrement = true;
    table.Columns.Add(column);

    column = new DataColumn("item", typeof(System.String));
    table.Columns.Add(column);

    // Add ten rows.
    DataRow row;
    for (int i = 0; i <= 9; i++)
    {
        row = table.NewRow();
        row["item"] = "item " + i;
        table.Rows.Add(row);
    }

    table.AcceptChanges();
    return table;
}

private static void PrintSchema(DataTable table, string label)
{
    // Display the schema of the supplied DataTable:
    Console.WriteLine(label);
    foreach (DataColumn column in table.Columns)
    {
        Console.WriteLine("\t{0}: {1}", column.ColumnName,
            column.DataType.Name);
    }
    Console.WriteLine();
}

Private Sub DemonstrateReadWriteXMLSchemaWithReader()
  Dim table As DataTable = CreateTestTable("XmlDemo")
  PrintSchema(table, "Original table")

  ' Write the schema to XML in a memory stream.
  Dim xmlStream As New System.IO.MemoryStream()
  table.WriteXmlSchema(xmlStream)

  ' Rewind the memory stream.
  xmlStream.Position = 0

  Dim newTable As New DataTable
  Dim reader As New System.Xml.XmlTextReader(xmlStream)
  newTable.ReadXmlSchema(reader)

  ' Print out values in the table.
  PrintSchema(newTable, "New Table")
End Sub

Private Function CreateTestTable(ByVal tableName As String) _
      As DataTable
  ' Create a test DataTable with two columns and a few rows.
  Dim table As New DataTable(tableName)
  Dim column As New DataColumn("id", GetType(System.Int32))
  column.AutoIncrement = True
  table.Columns.Add(column)

  column = New DataColumn("item", GetType(System.String))
  table.Columns.Add(column)

  ' Add ten rows.
  Dim row As DataRow
  For i As Integer = 0 To 9
    row = table.NewRow()
    row("item") = "item " & i
    table.Rows.Add(row)
  Next i

  table.AcceptChanges()
  Return table
End Function

Private Sub PrintSchema(ByVal table As DataTable, _
      ByVal label As String)
  ' Display the schema of the supplied DataTable:
  Console.WriteLine(label)
  For Each column As DataColumn In table.Columns
    Console.WriteLine("{0}{1}: {2}", ControlChars.Tab, _
      column.ColumnName, column.DataType.Name)
  Next column
End Sub

注解

ReadXmlSchema使用方法创建的DataTable架构。架构包括表、关系和约束定义。

若要将架构写入 XML 文档，请使用 WriteXmlSchema 方法。

XML 架构根据 XSD 标准进行解释。

如果 msdata：DataType 和 xs：type 类型不匹配，则可能发生数据损坏。不会引发异常。

通常，在 ReadXmlSchema 调用 ReadXml 用于填充的方法之前调用方法 DataTable。

注意

使用 XML 架构创建嵌套关系的方法是使用隐式嵌套元素。此外，可以重新连接嵌套关系，以使用显式列名。对于相应的 DataTable，必须隐式嵌套元素才能参与嵌套关系。

另请参阅

适用于

ReadXmlSchema(String)

Source:: DataTable.cs

Source:: DataTable.cs

Source:: DataTable.cs

从指定的文件将 XML 架构读入 DataTable。

public:
 void ReadXmlSchema(System::String ^ fileName);

public void ReadXmlSchema (string fileName);

member this.ReadXmlSchema : string -> unit

Public Sub ReadXmlSchema (fileName As String)

参数

fileName: String

从中读取架构信息的文件的名称。

示例

以下控制台应用程序创建一个新的 DataTable，并将该表的架构写入文件。然后，该示例创建一个新的 DataTable ，并使用文件作为其源从保存的 XML 架构中读取其架构。

private static void DemonstrateReadWriteXMLSchemaWithFile()
{
    DataTable table = CreateTestTable("XmlDemo");
    PrintSchema(table, "Original table");

    // Write the schema to XML in a file.
    string xmlFile = "C:\\SchemaDemo.xml";
    table.WriteXmlSchema(xmlFile);

    DataTable newTable = new DataTable();
    newTable.ReadXmlSchema(xmlFile);

    // Print out values in the table.
    PrintSchema(newTable, "New table");
}

private static DataTable CreateTestTable(string tableName)
{
    // Create a test DataTable with two columns and a few rows.
    DataTable table = new DataTable(tableName);
    DataColumn column = new DataColumn("id", typeof(System.Int32));
    column.AutoIncrement = true;
    table.Columns.Add(column);

    column = new DataColumn("item", typeof(System.String));
    table.Columns.Add(column);

    // Add ten rows.
    DataRow row;
    for (int i = 0; i <= 9; i++)
    {
        row = table.NewRow();
        row["item"] = "item " + i;
        table.Rows.Add(row);
    }

    table.AcceptChanges();
    return table;
}

private static void PrintSchema(DataTable table, string label)
{
    // Display the schema of the supplied DataTable:
    Console.WriteLine(label);
    foreach (DataColumn column in table.Columns)
    {
        Console.WriteLine("\t{0}: {1}", column.ColumnName,
            column.DataType.Name);
    }
    Console.WriteLine();
}

Private Sub DemonstrateReadWriteXMLSchemaWithFile()
  Dim table As DataTable = CreateTestTable("XmlDemo")
  PrintSchema(table, "Original table")

  Dim xmlFile As String = "SchemaDemo.xml"

  ' Write the schema to XML.
  table.WriteXmlSchema(xmlFile)

  Dim newTable As New DataTable
  newTable.ReadXmlSchema(xmlFile)

  ' Print out values in the table.
  PrintSchema(newTable, "New Table")
End Sub

Private Function CreateTestTable(ByVal tableName As String) _
      As DataTable
  ' Create a test DataTable with two columns and a few rows.
  Dim table As New DataTable(tableName)
  Dim column As New DataColumn("id", GetType(System.Int32))
  column.AutoIncrement = True
  table.Columns.Add(column)

  column = New DataColumn("item", GetType(System.String))
  table.Columns.Add(column)

  ' Add ten rows.
  Dim row As DataRow
  For i As Integer = 0 To 9
    row = table.NewRow()
    row("item") = "item " & i
    table.Rows.Add(row)
  Next i

  table.AcceptChanges()
  Return table
End Function

Private Sub PrintSchema(ByVal table As DataTable, _
      ByVal label As String)
  ' Display the schema of the supplied DataTable:
  Console.WriteLine(label)
  For Each column As DataColumn In table.Columns
    Console.WriteLine("{0}{1}: {2}", ControlChars.Tab, _
      column.ColumnName, column.DataType.Name)
  Next column
End Sub

注解

ReadXmlSchema使用方法创建的DataTable架构。架构包括表、关系和约束定义。

若要将架构写入 XML 文档，请使用 WriteXmlSchema 方法。

XML 架构根据 XSD 标准进行解释。

如果 msdata：DataType 和 xs：type 类型不匹配，则可能发生数据损坏。不会引发异常。

通常，在 ReadXmlSchema 调用 ReadXml 用于填充的方法之前调用方法 DataTable。

若要使用 XML 架构创建嵌套关系，请使用隐式嵌套元素。还可以重新配置嵌套关系以使用显式列名。元素必须隐式嵌套，以便相应的 DataTable 参与嵌套关系。

另请参阅

适用于

ReadXmlSchema(TextReader)

Source:: DataTable.cs

Source:: DataTable.cs

Source:: DataTable.cs

使用指定的 TextReader 将 XML 架构读入 DataTable。

public:
 void ReadXmlSchema(System::IO::TextReader ^ reader);

public void ReadXmlSchema (System.IO.TextReader? reader);

public void ReadXmlSchema (System.IO.TextReader reader);

member this.ReadXmlSchema : System.IO.TextReader -> unit

Public Sub ReadXmlSchema (reader As TextReader)

参数

reader: TextReader

用于读取架构信息的 TextReader。

示例

以下控制台应用程序创建一个新的 DataTable，并将该表的架构写入。MemoryStream 然后，该示例创建一个新的 DataTable ，并使用继承自 TextReader) 作为源的 (从保存的 XML 架构读取其架构StreamReader。

private static void DemonstrateReadWriteXMLSchemaWithReader()
{
    DataTable table = CreateTestTable("XmlDemo");
    PrintSchema(table, "Original table");

    // Write the schema to XML in a memory stream.
    System.IO.MemoryStream xmlStream = new System.IO.MemoryStream();
    table.WriteXmlSchema(xmlStream);

    // Rewind the memory stream.
    xmlStream.Position = 0;

    DataTable newTable = new DataTable();
    System.IO.StreamReader reader =
        new System.IO.StreamReader(xmlStream);
    newTable.ReadXmlSchema(reader);

    // Print out values in the table.
    PrintSchema(newTable, "New table");
}

private static DataTable CreateTestTable(string tableName)
{
    // Create a test DataTable with two columns and a few rows.
    DataTable table = new DataTable(tableName);
    DataColumn column = new DataColumn("id", typeof(System.Int32));
    column.AutoIncrement = true;
    table.Columns.Add(column);

    column = new DataColumn("item", typeof(System.String));
    table.Columns.Add(column);

    // Add ten rows.
    DataRow row;
    for (int i = 0; i <= 9; i++)
    {
        row = table.NewRow();
        row["item"] = "item " + i;
        table.Rows.Add(row);
    }

    table.AcceptChanges();
    return table;
}

private static void PrintSchema(DataTable table, string label)
{
    // Display the schema of the supplied DataTable:
    Console.WriteLine(label);
    foreach (DataColumn column in table.Columns)
    {
        Console.WriteLine("\t{0}: {1}",
            column.ColumnName, column.DataType.Name);
    }
    Console.WriteLine();
}

Private Sub DemonstrateReadWriteXMLSchemaWithReader()
  Dim table As DataTable = CreateTestTable("XmlDemo")
  PrintSchema(table, "Original table")

  ' Write the schema to XML in a memory stream.
  Dim xmlStream As New System.IO.MemoryStream()
  table.WriteXmlSchema(xmlStream)

  ' Rewind the memory stream.
  xmlStream.Position = 0

  Dim newTable As New DataTable
  Dim reader As New System.IO.StreamReader(xmlStream)
  newTable.ReadXmlSchema(reader)

  ' Print out values in the table.
  PrintSchema(newTable, "New Table")
End Sub

Private Function CreateTestTable(ByVal tableName As String) _
  As DataTable

  ' Create a test DataTable with two columns and a few rows.
  Dim table As New DataTable(tableName)
  Dim column As New DataColumn("id", GetType(System.Int32))
  column.AutoIncrement = True
  table.Columns.Add(column)

  column = New DataColumn("item", GetType(System.String))
  table.Columns.Add(column)

  ' Add ten rows.
  Dim row As DataRow
  For i As Integer = 0 To 9
    row = table.NewRow()
    row("item") = "item " & i
    table.Rows.Add(row)
  Next i

  table.AcceptChanges()
  Return table
End Function

Private Sub PrintSchema(ByVal table As DataTable, _
  ByVal label As String)

  ' Display the schema of the supplied DataTable:
  Console.WriteLine(label)
  For Each column As DataColumn In table.Columns
    Console.WriteLine("{0}{1}: {2}", ControlChars.Tab, _
      column.ColumnName, column.DataType.Name)
  Next column
End Sub

注解

ReadXmlSchema使用方法创建的DataTable架构。架构包括表、关系和约束定义。

若要将架构写入 XML 文档，请使用 WriteXmlSchema 方法。

XML 架构根据 XSD 标准进行解释。

如果 msdata：DataType 和 xs：type 类型不匹配，则可能发生数据损坏。不会引发异常。

通常，在 ReadXmlSchema 调用 ReadXml 用于填充的方法之前调用方法 DataTable。

另请参阅

适用于

ReadXmlSchema(Stream)

Source:: DataTable.cs

Source:: DataTable.cs

Source:: DataTable.cs

使用指定的流将 XML 架构读入 DataTable。

public:
 void ReadXmlSchema(System::IO::Stream ^ stream);

public void ReadXmlSchema (System.IO.Stream? stream);

public void ReadXmlSchema (System.IO.Stream stream);

member this.ReadXmlSchema : System.IO.Stream -> unit

Public Sub ReadXmlSchema (stream As Stream)

参数

stream: Stream

用于读取架构的流。

示例

以下控制台应用程序创建一个新的 DataTable，并将该表的架构写入。MemoryStream 然后，该示例创建一个新的 DataTable ，并从保存的 XML 架构中读取其架构。

private static void DemonstrateReadWriteXMLSchemaWithStream()
{
    DataTable table = CreateTestTable("XmlDemo");
    PrintSchema(table, "Original table");

    // Write the schema to XML in a memory stream.
    System.IO.MemoryStream xmlStream = new System.IO.MemoryStream();
    table.WriteXmlSchema(xmlStream);

    // Rewind the memory stream.
    xmlStream.Position = 0;

    DataTable newTable = new DataTable();
    newTable.ReadXmlSchema(xmlStream);

    // Print out values in the table.
    PrintSchema(newTable, "New table");
}

private static DataTable CreateTestTable(string tableName)
{
    // Create a test DataTable with two columns and a few rows.
    DataTable table = new DataTable(tableName);
    DataColumn column = new DataColumn("id", typeof(System.Int32));
    column.AutoIncrement = true;
    table.Columns.Add(column);

    column = new DataColumn("item", typeof(System.String));
    table.Columns.Add(column);

    // Add ten rows.
    DataRow row;
    for (int i = 0; i <= 9; i++)
    {
        row = table.NewRow();
        row["item"] = "item " + i;
        table.Rows.Add(row);
    }

    table.AcceptChanges();
    return table;
}

private static void PrintSchema(DataTable table, string label)
{
    // Display the schema of the supplied DataTable:
    Console.WriteLine(label);
    foreach (DataColumn column in table.Columns)
    {
        Console.WriteLine("\t{0}: {1}", column.ColumnName,
            column.DataType.Name);
    }
    Console.WriteLine();
}

Private Sub DemonstrateReadWriteXMLSchemaWithStream()
  Dim table As DataTable = CreateTestTable("XmlDemo")
  PrintSchema(table, "Original table")

  ' Write the schema to XML in a memory stream.
  Dim xmlStream As New System.IO.MemoryStream()
  table.WriteXmlSchema(xmlStream)

  ' Rewind the memory stream.
  xmlStream.Position = 0

  Dim newTable As New DataTable
  newTable.ReadXmlSchema(xmlStream)

  ' Print out values in the table.
  PrintSchema(newTable, "New Table")
End Sub

Private Function CreateTestTable(ByVal tableName As String) _
  As DataTable

  ' Create a test DataTable with two columns and a few rows.
  Dim table As New DataTable(tableName)
  Dim column As New DataColumn("id", GetType(System.Int32))
  column.AutoIncrement = True
  table.Columns.Add(column)

  column = New DataColumn("item", GetType(System.String))
  table.Columns.Add(column)

  ' Add ten rows.
  Dim row As DataRow
  For i As Integer = 0 To 9
    row = table.NewRow()
    row("item") = "item " & i
    table.Rows.Add(row)
  Next i

  table.AcceptChanges()
  Return table
End Function

Private Sub PrintSchema(ByVal table As DataTable, _
  ByVal label As String)

  ' Display the schema of the supplied DataTable:
  Console.WriteLine(label)
  For Each column As DataColumn In table.Columns
    Console.WriteLine("{0}{1}: {2}", ControlChars.Tab, _
      column.ColumnName, column.DataType.Name)
  Next column
End Sub

注解

ReadXmlSchema使用方法创建的DataTable架构。架构包括表、关系和约束定义。

若要将架构写入 XML 文档，请使用 WriteXmlSchema 方法。

XML 架构根据 XSD 标准进行解释。

如果 msdata：DataType 和 xs：type 类型不匹配，则可能发生数据损坏。不会引发异常。

通常，在 ReadXmlSchema 调用 ReadXml 用于填充的方法之前调用方法 DataTable。

若要使用 XML 架构创建嵌套关系，请使用隐式嵌套元素。还可以将嵌套关系配置为使用显式列名。元素必须隐式嵌套，以便相应的 DataTable 参与嵌套关系。

另请参阅

适用于

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通过

DataTable.ReadXmlSchema 方法

定义

重载

注解

ReadXmlSchema(XmlReader)

参数

示例

注解

另请参阅

适用于

ReadXmlSchema(String)

参数

示例

注解

另请参阅

适用于

ReadXmlSchema(TextReader)

参数

示例

注解

另请参阅

适用于

ReadXmlSchema(Stream)

参数

示例

注解

另请参阅

适用于

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