Search and Replace with the Selection object

Another common task for a text editor is search/replace functionality. The C1Editor has built-in commands for find and replace (implemented above using the ShowDialog command), but in some cases you may want to implement this programmatically.

The code below shows how you can perform search and replace tasks using the Selection object:

To write code in C#

void replaceUsingSelection_Click(object sender, EventArgs e)
{
    // strings to search and replace
    string search = "user";
    string replace = "customer";
    // do the work
    int count = 0;
    for (int start = 0; ; start += search.Length)
    {
        // get text (notice new line handling)
        string txt = this.c1Editor1.Text;
        txt = txt.Replace("\r\n", "\n");
        // find text, break when done
        start = txt.IndexOf(search, start, StringComparison.OrdinalIgnoreCase);
        if (start < 0)
        {
            break;
        }
        // select match
        this.c1Editor1.Select(start, search.Length);
        // replace text and make it bold
        this.c1Editor1.Selection.Text = replace;
        this.c1Editor1.Selection.ApplyTag("strong");
    }
    // done
    MessageBox.Show(string.Format("Done, {0} instances found.", count));
}

The code implements a loop that gets the editor's content as plain text and looks for a "search" string using the standard string.IndexOf method. When a match is found, the code selects the string using the Select method and then replaces the text by modifying the Text property of the Selection object. As a bonus, the code also makes the replacement bold by applying the "strong" tag to the replacement text.

A good degree of compatibility with the familiar object model of the TextBox and RichTextBox classes is an important feature of the C1Editor.