CharacterRange(Int32, Int32) Constructor

Definition

Namespace:

System.Drawing

Assembly:

System.Drawing.Common.dll

Source:

CharacterRange.cs

Initializes a new instance of the CharacterRange structure, specifying a range of character positions within a string.

C#

public CharacterRange(int First, int Length);

Parameters

First

Int32

The position of the first character in the range. For example, if First is set to 0, the first position of the range is position 0 in the string.

Length

Int32

The number of positions in the range.

Examples

The following code example demonstrates how to create a CharacterRange and use it to highlight part of a string. This example is designed to be used with Windows Forms. Paste the example into a form and call the HighlightACharacterRange method when handling the form's Paint event, passing e as PaintEventArgs.

C#

private void HighlightACharacterRange(PaintEventArgs e)
{

    // Declare the string to draw.
    string message = "This is the string to highlight a word in.";

    // Declare the word to highlight.
    string searchWord = "string";

    // Create a CharacterRange array with the searchWord 
    // location and length.
    CharacterRange[] ranges = 
        new CharacterRange[]{new CharacterRange
        (message.IndexOf(searchWord), searchWord.Length)};

    // Construct a StringFormat object.
    StringFormat stringFormat1 = new StringFormat();

    // Set the ranges on the StringFormat object.
    stringFormat1.SetMeasurableCharacterRanges(ranges);

    // Declare the font to write the message in.
    Font largeFont = new Font(FontFamily.GenericSansSerif, 16.0F,
        GraphicsUnit.Pixel);

    // Construct a new Rectangle.
    Rectangle displayRectangle = new Rectangle(20, 20, 200, 100);

    // Convert the Rectangle to a RectangleF.
    RectangleF displayRectangleF = (RectangleF)displayRectangle;

    // Get the Region to highlight by calling the 
    // MeasureCharacterRanges method.
    Region[] charRegion = e.Graphics.MeasureCharacterRanges(message, 
        largeFont, displayRectangleF, stringFormat1);

    // Draw the message string on the form.
    e.Graphics.DrawString(message, largeFont, Brushes.Blue, 
        displayRectangleF);

    // Fill in the region using a semi-transparent color.
    e.Graphics.FillRegion(new SolidBrush(Color.FromArgb(50, Color.Fuchsia)), 
        charRegion[0]);

    largeFont.Dispose();
}

Applies to