TextInfo.ReadOnly(TextInfo) Method

Definition

Namespace:

System.Globalization

Assemblies:

netstandard.dll, System.Runtime.dll

Source:

TextInfo.cs

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

C#

public static System.Globalization.TextInfo ReadOnly(System.Globalization.TextInfo textInfo);

Parameters

textInfo

TextInfo

A TextInfo object.

Returns

TextInfo

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.

Exceptions

ArgumentNullException

textInfo is null.

Examples

The following code example demonstrates the Clone and ReadOnly methods.

C#

// 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)
        {
        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.

*/

Applies to

See also

• MemberwiseClone()