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TextInfo.ReadOnly Method

Returns a read-only version of the specified TextInfo object.

Namespace: System.Globalization
Assembly: mscorlib (in mscorlib.dll)

[ComVisibleAttribute(false)] 
public static TextInfo ReadOnly (
	TextInfo textInfo
)
/** @attribute ComVisibleAttribute(false) */ 
public static TextInfo ReadOnly (
	TextInfo textInfo
)
ComVisibleAttribute(false) 
public static function ReadOnly (
	textInfo : TextInfo
) : TextInfo
Not applicable.

Parameters

textInfo

A TextInfo object.

Return Value

The TextInfo object specified by the textInfo parameter, if textInfo is read-only. -or- A read-only memberwise clone of the TextInfo object specified by textInfo, if textInfo is not read-only.

Exception typeCondition

ArgumentNullException

textInfo is null.

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.

*/

Windows 98, Windows Server 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0
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