Rtf Example

// **** TO TEST:
// **** Create a new WinForms project in VisualStudio and follow the next 2 following steps

// ******************************************************************************
// 1) Replace the class Form1 inside "Form1.cs" file with the following code (be careful not to copy the 2nd step):
public partial class Form1 : Form
{
    // Dictionary<TKey,TValue> is preferable to HashTable
    Dictionary<string, string> rtfByRichTextBoxName = new Dictionary<string, string>();

    public Form1()
    {
        InitializeComponent();

        // subscribe the events
        this.comboBoxSelectRichTextBox.SelectedIndexChanged += new EventHandler(comboBoxSelectRichTextBox_SelectedIndexChanged);

        // here we create 3 richTextBox (I initialized them with some rtf text using WordPad)
        this.rtfByRichTextBoxName.Add("RichTextBox A", @"{\rtf1\ansi\ansicpg1252\deff0\deflang1040{\fonttbl{\f0\fnil\fcharset0 Calibri;}}
                                                         {\colortbl ;\red255\green0\blue0;}
                                                         {\*\generator Msftedit 5.41.21.2510;}\viewkind4\uc1\pard\sa200\sl276\slmult1\cf1\lang16\f0\fs22 Hello World \cf0 from A\par}");
        this.rtfByRichTextBoxName.Add("RichTextBox B", @"{\rtf1\ansi\ansicpg1252\deff0\deflang1040{\fonttbl{\f0\fnil\fcharset0 Calibri;}}
                                                         {\colortbl ;\red0\green0\blue255;}
                                                         {\*\generator Msftedit 5.41.21.2510;}\viewkind4\uc1\pard\sa200\sl276\slmult1\cf1\lang16\f0\fs22 Hello World \cf0 from B\par}");
        this.rtfByRichTextBoxName.Add("RichTextBox C", @"{\rtf1\ansi\ansicpg1252\deff0\deflang1040{\fonttbl{\f0\fnil\fcharset0 Calibri;}}
                                                         {\colortbl ;\red0\green255\blue0;}
                                                         {\*\generator Msftedit 5.41.21.2510;}\viewkind4\uc1\pard\sa200\sl276\slmult1\cf1\lang16\f0\fs22 Hello World \cf0 from C\par}");

        // fill the combobox with the available richtextboxes
        foreach (var key in this.rtfByRichTextBoxName.Keys)
            this.comboBoxSelectRichTextBox.Items.Add(key);
        // and select the first item to trigger the event
        this.comboBoxSelectRichTextBox.SelectedIndex = 0;
    }

    void comboBoxSelectRichTextBox_SelectedIndexChanged(object sender, EventArgs e)
    {
        // N.B. we use the Tag property of the richTextBox to store the current key of the richTextBox

        string oldSelectedKey = null;
        if (this.richTextBox1.Tag != null)
            oldSelectedKey = this.richTextBox1.Tag.ToString();

        string newSelectedKey = this.comboBoxSelectRichTextBox.SelectedItem.ToString();

        // if we are switching to a new richTextBox, update the Rtf to the dictionary
        // (to keep possible user changes)
        if(oldSelectedKey != null && newSelectedKey != oldSelectedKey)
            this.rtfByRichTextBoxName[oldSelectedKey] = this.richTextBox1.Rtf;

        // now switch to the new text
        this.richTextBox1.Rtf = this.rtfByRichTextBoxName[newSelectedKey];

        this.richTextBox1.Tag = newSelectedKey;
    }


    private void buttonSetSelectedTextColor_Click(object sender, EventArgs e)
    {
        ColorDialog dlg = new ColorDialog();
        dlg.Color = this.richTextBox1.SelectionColor;
        if (dlg.ShowDialog() == DialogResult.OK)
            this.richTextBox1.SelectionColor = dlg.Color;
    }
}

// ******************************************************************************
// 2) Replace the class Form1 inside "Form1.Designer.cs" file with the following code:

partial class Form1
{
    /// <summary>
    /// Required designer variable.
    /// </summary>
    private System.ComponentModel.IContainer components = null;

    /// <summary>
    /// Clean up any resources being used.
    /// </summary>
    /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
    protected override void Dispose(bool disposing)
    {
        if (disposing && (components != null))
        {
            components.Dispose();
        }
        base.Dispose(disposing);
    }

    #region Windows Form Designer generated code

    /// <summary>
    /// Required method for Designer support - do not modify
    /// the contents of this method with the code editor.
    /// </summary>
    private void InitializeComponent()
    {
        this.richTextBox1 = new System.Windows.Forms.RichTextBox();
        this.buttonSetSelectedTextColor = new System.Windows.Forms.Button();
        this.comboBoxSelectRichTextBox = new System.Windows.Forms.ComboBox();
        this.label1 = new System.Windows.Forms.Label();
        this.SuspendLayout();
        //
        // richTextBox1
        //
        this.richTextBox1.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
                    | System.Windows.Forms.AnchorStyles.Left)
                    | System.Windows.Forms.AnchorStyles.Right)));
        this.richTextBox1.Location = new System.Drawing.Point(12, 116);
        this.richTextBox1.Name = "richTextBox1";
        this.richTextBox1.Size = new System.Drawing.Size(508, 281);
        this.richTextBox1.TabIndex = 0;
        this.richTextBox1.Text = "";
        //
        // buttonSetSelectedTextColor
        //
        this.buttonSetSelectedTextColor.Location = new System.Drawing.Point(12, 87);
        this.buttonSetSelectedTextColor.Name = "buttonSetSelectedTextColor";
        this.buttonSetSelectedTextColor.Size = new System.Drawing.Size(137, 23);
        this.buttonSetSelectedTextColor.TabIndex = 2;
        this.buttonSetSelectedTextColor.Text = "Set Selected Text Color...";
        this.buttonSetSelectedTextColor.UseVisualStyleBackColor = true;
        this.buttonSetSelectedTextColor.Click += new System.EventHandler(this.buttonSetSelectedTextColor_Click);
        //
        // comboBoxSelectRichTextBox
        //
        this.comboBoxSelectRichTextBox.DropDownStyle = System.Windows.Forms.ComboBoxStyle.DropDownList;
        this.comboBoxSelectRichTextBox.FormattingEnabled = true;
        this.comboBoxSelectRichTextBox.Location = new System.Drawing.Point(159, 6);
        this.comboBoxSelectRichTextBox.Name = "comboBoxSelectRichTextBox";
        this.comboBoxSelectRichTextBox.Size = new System.Drawing.Size(215, 21);
        this.comboBoxSelectRichTextBox.TabIndex = 3;
        //
        // label1
        //
        this.label1.AutoSize = true;
        this.label1.Location = new System.Drawing.Point(12, 9);
        this.label1.Name = "label1";
        this.label1.Size = new System.Drawing.Size(141, 13);
        this.label1.TabIndex = 4;
        this.label1.Text = "Current Visible RichTextBox:";
        //
        // Form1
        //
        this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
        this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
        this.ClientSize = new System.Drawing.Size(532, 409);
        this.Controls.Add(this.label1);
        this.Controls.Add(this.comboBoxSelectRichTextBox);
        this.Controls.Add(this.buttonSetSelectedTextColor);
        this.Controls.Add(this.richTextBox1);
        this.Name = "Form1";
        this.Text = "Form1";
        this.ResumeLayout(false);
        this.PerformLayout();

    }

    #endregion

    private System.Windows.Forms.RichTextBox richTextBox1;
    private System.Windows.Forms.Button buttonSetSelectedTextColor;
    private System.Windows.Forms.ComboBox comboBoxSelectRichTextBox;
    private System.Windows.Forms.Label label1;
}