TextInfo.ReadOnly(TextInfo) 方法

定义

返回指定的 TextInfo 对象的只读版本。Returns a read-only version of the specified TextInfo object.

public:
 static System::Globalization::TextInfo ^ ReadOnly(System::Globalization::TextInfo ^ textInfo);
public static System.Globalization.TextInfo ReadOnly (System.Globalization.TextInfo textInfo);
[System.Runtime.InteropServices.ComVisible(false)]
public static System.Globalization.TextInfo ReadOnly (System.Globalization.TextInfo textInfo);
static member ReadOnly : System.Globalization.TextInfo -> System.Globalization.TextInfo
[<System.Runtime.InteropServices.ComVisible(false)>]
static member ReadOnly : System.Globalization.TextInfo -> System.Globalization.TextInfo
Public Shared Function ReadOnly (textInfo As TextInfo) As TextInfo

参数

textInfo
TextInfo

TextInfo 对象。A TextInfo object.

返回

TextInfo

如果 textInfo 是只读的,则为由 textInfo 参数指定的 TextInfo 对象。The TextInfo object specified by the textInfo parameter, if textInfo is read-only.

- 或 --or- 如果 textInfo 不是只读的,则为由 textInfo 指定的 TextInfo 对象的只读成员副本。A read-only memberwise clone of the TextInfo object specified by textInfo, if textInfo is not read-only.

属性

例外

textInfo 为 null。textInfo is null.

示例

下面的代码示例演示了 CloneReadOnly 方法。The following code example demonstrates the Clone and ReadOnly methods.

// This example demonstrates the TextInfo.Clone() and
// TextInfo.ReadOnly() methods.

using System;
using System.Globalization;

class Sample
{
    public static void Main()
    {
// Get the TextInfo of a predefined culture that ships with
// the .NET Framework.
    CultureInfo ci = new CultureInfo("en-US");
    TextInfo ti1 = ci.TextInfo;

// Display whether the TextInfo is read-only or not.
    DisplayReadOnly("1) The original TextInfo object", ti1);
    Console.WriteLine();

// Create a clone of the original TextInfo and cast the clone to a TextInfo type.
    Console.WriteLine("2a) Create a clone of the original TextInfo object...");
    TextInfo ti2 = (TextInfo)ti1.Clone();

// Display whether the clone is read-only.
    DisplayReadOnly("2b) The TextInfo clone", ti2);

// Set the ListSeparator property on the TextInfo clone.
    Console.WriteLine("2c) The original value of the clone's ListSeparator " +
                      "property is \"{0}\".", ti2.ListSeparator);
    ti2.ListSeparator = "/";
    Console.WriteLine("2d) The new value of the clone's ListSeparator " +
                      "property is \"{0}\".\n", ti2.ListSeparator);

// Create a read-only clone of the original TextInfo.
    Console.WriteLine("3a) Create a read-only clone of the original TextInfo object...");
    TextInfo ti3 = TextInfo.ReadOnly(ti1);

// Display whether the read-only clone is actually read-only.
    DisplayReadOnly("3b) The TextInfo clone", ti3);

// Try to set the ListSeparator property of a read-only TextInfo object. Use the
// IsReadOnly property again to determine whether to attempt the set operation. You
// could use a try-catch block instead and catch an InvalidOperationException when
// the set operation fails, but that programming technique is inefficient.
    Console.WriteLine("3c) Try to set the read-only clone's LineSeparator " +
                      "property.");
    if (ti3.IsReadOnly == true)
        {
        Console.WriteLine("3d) The set operation is invalid.");
        }
    else
        {
        // This clause is not executed.
        ti3.ListSeparator = "/";
        Console.WriteLine("3d) The new value of the clone's ListSeparator " +
                          "property is \"{0}\".\n", ti2.ListSeparator);
        }
    }

    private static void DisplayReadOnly(string caption, TextInfo ti)
    {
    Console.WriteLine("{0} is {1}read-only.",
                      caption, ti.IsReadOnly ? "" : "not ");
    }
}

/*
This code example produces the following results:

1) The original TextInfo object is not read-only.

2a) Create a clone of the original TextInfo object...
2b) The TextInfo clone is not read-only.
2c) The original value of the clone's ListSeparator property is ",".
2d) The new value of the clone's ListSeparator property is "/".

3a) Create a read-only clone of the original TextInfo object...
3b) The TextInfo clone is read-only.
3c) Try to set the read-only clone's LineSeparator property.
3d) The set operation is invalid.

*/
' This example demonstrates the TextInfo.Clone() and
' TextInfo.ReadOnly() methods.

Imports System.Globalization

Class Sample
    Public Shared Sub Main() 
        ' Get the TextInfo of a predefined culture that ships with 
        ' the .NET Framework.
        Dim ci As New CultureInfo("en-US")
        Dim ti1 As TextInfo = ci.TextInfo
        
        ' Display whether the TextInfo is read-only or not.
        DisplayReadOnly("1) The original TextInfo object", ti1)
        Console.WriteLine()
        
        ' Create a clone of the original TextInfo and cast the clone to a TextInfo type.
        Console.WriteLine("2a) Create a clone of the original TextInfo object...")
        Dim ti2 As TextInfo = CType(ti1.Clone(), TextInfo)
        
        ' Display whether the clone is read-only.
        DisplayReadOnly("2b) The TextInfo clone", ti2)
        
        ' Set the ListSeparator property on the TextInfo clone.
        Console.WriteLine("2c) The original value of the clone's ListSeparator " & _
                          "property is ""{0}"".", ti2.ListSeparator)
        ti2.ListSeparator = "/"
        Console.WriteLine("2d) The new value of the clone's ListSeparator " & _ 
                          "property is ""{0}""." & vbCrLf, ti2.ListSeparator)
        
        ' Create a read-only clone of the original TextInfo.
        Console.WriteLine("3a) Create a read-only clone of the original TextInfo object...")
        Dim ti3 As TextInfo = TextInfo.ReadOnly(ti1)
        
        ' Display whether the read-only clone is actually read-only.
        DisplayReadOnly("3b) The TextInfo clone", ti3)
        
        ' Try to set the ListSeparator property of a read-only TextInfo object. Use the
        ' IsReadOnly property again to determine whether to attempt the set operation. You 
        ' could use a try-catch block instead and catch an InvalidOperationException when
        ' the set operation fails, but that programming technique is inefficient.
        Console.WriteLine("3c) Try to set the read-only clone's LineSeparator property.")
        If ti3.IsReadOnly = True Then
            Console.WriteLine("3d) The set operation is invalid.")
        Else
            ' This clause is not executed.
            ti3.ListSeparator = "/"
            Console.WriteLine("3d) The new value of the clone's ListSeparator " & _ 
                              "property is ""{0}""." & vbCrLf, ti2.ListSeparator)
        End If
    
    End Sub
    
    Private Shared Sub DisplayReadOnly(ByVal caption As String, ByVal ti As TextInfo)
        Dim middle As String
        If ti.IsReadOnly = True Then
            middle = ""
        Else 
            middle = "not "
        End If        
        Console.WriteLine("{0} is {1}read-only.", caption, middle)
    End Sub
End Class

'
'This code example produces the following results:
'
'1) The original TextInfo object is not read-only.
'
'2a) Create a clone of the original TextInfo object...
'2b) The TextInfo clone is not read-only.
'2c) The original value of the clone's ListSeparator property is ",".
'2d) The new value of the clone's ListSeparator property is "/".
'
'3a) Create a read-only clone of the original TextInfo object...
'3b) The TextInfo clone is read-only.
'3c) Try to set the read-only clone's LineSeparator property.
'3d) The set operation is invalid.
'

适用于

另请参阅