diff --git a/README.md b/README.md
index be1a588..18651f0 100644
--- a/README.md
+++ b/README.md
@@ -19,6 +19,7 @@ DFL is a Win32 windowing library for the D language.
 ![screen shot](./examples/timer/image/screenshot.png "screen shot")
 ![screen shot](./examples/contextmenu/image/screenshot.png "screen shot")
 ![screen shot](./examples/toolbar/image/screenshot.png "screen shot")
+![screen shot](./examples/richtextbox/image/screenshot.png "screen shot")
 
 ## Recent major features
 - DUB is available for DFL.
diff --git a/examples/richtextbox/.gitignore b/examples/richtextbox/.gitignore
new file mode 100644
index 0000000..60a5f2a
--- /dev/null
+++ b/examples/richtextbox/.gitignore
@@ -0,0 +1,16 @@
+.dub
+docs.json
+__dummy.html
+docs/
+/hello_dfl
+hello_dfl.so
+hello_dfl.dylib
+hello_dfl.dll
+hello_dfl.a
+hello_dfl.lib
+hello_dfl-test-*
+*.exe
+*.pdb
+*.o
+*.obj
+*.lst
diff --git a/examples/richtextbox/.vscode/launch.json b/examples/richtextbox/.vscode/launch.json
new file mode 100644
index 0000000..c6db41a
--- /dev/null
+++ b/examples/richtextbox/.vscode/launch.json
@@ -0,0 +1,13 @@
+{
+    "version": "0.2.0",
+    "configurations": [
+        {
+            "name": "C++ Launch (Windows) richtextbox",
+            "type": "cppvsdbg",
+            "request": "launch",
+            "cwd": "${workspaceRoot}",
+            "program": "./bin/richtextbox_sample.exe",
+            "console": "internalConsole"
+        }
+    ]
+}
\ No newline at end of file
diff --git a/examples/richtextbox/.vscode/tasks.json b/examples/richtextbox/.vscode/tasks.json
new file mode 100644
index 0000000..ba5b899
--- /dev/null
+++ b/examples/richtextbox/.vscode/tasks.json
@@ -0,0 +1,23 @@
+{
+	"version": "2.0.0",
+	"tasks": [
+		{
+			"type": "dub",
+			"run": false,
+			"cwd": ".",
+			"compiler": "$current",
+			"archType": "$current",
+			"buildType": "$current",
+			"configuration": "$current",
+			"problemMatcher": [
+				"$dmd"
+			],
+			"group": "build",
+			"label": "dub: Build richtextbox_sample",
+			"detail": "dub build --compiler=dmd.EXE -a=x86_64 -b=debug -c=application",
+			"presentation": {
+				"clear": true
+			}
+		}
+	]
+}
\ No newline at end of file
diff --git a/examples/richtextbox/README.md b/examples/richtextbox/README.md
new file mode 100644
index 0000000..b1a86ca
--- /dev/null
+++ b/examples/richtextbox/README.md
@@ -0,0 +1,2 @@
+# Screen Shot
+![screen shot](./image/screenshot.png "screen shot")
diff --git a/examples/richtextbox/dub.json b/examples/richtextbox/dub.json
new file mode 100644
index 0000000..9ea257d
--- /dev/null
+++ b/examples/richtextbox/dub.json
@@ -0,0 +1,16 @@
+{
+	"authors": ["haru-s"],
+	"copyright": "Copyright (C) 2023 haru-s",
+	"description": "DFL sample code.",
+	"name": "richtextbox_sample",
+	"targetType": "executable",
+	"targetPath": "bin",
+	"dependencies": {
+		"dfl": {
+			"path": "../../../dfl"
+		}
+	},
+	"lflags-windows-x86_omf-dmd":    ["/exet:nt/su:windows:6.0"],
+	"lflags-windows-x86_mscoff-dmd": ["/SUBSYSTEM:WINDOWS", "/ENTRY:mainCRTStartup"],
+	"lflags-windows-x86_64-dmd":     ["/SUBSYSTEM:WINDOWS", "/ENTRY:mainCRTStartup"]
+}
\ No newline at end of file
diff --git a/examples/richtextbox/image/screenshot.png b/examples/richtextbox/image/screenshot.png
new file mode 100644
index 0000000..f2ce417
Binary files /dev/null and b/examples/richtextbox/image/screenshot.png differ
diff --git a/examples/richtextbox/richtextbox.code-workspace b/examples/richtextbox/richtextbox.code-workspace
new file mode 100644
index 0000000..7e696bc
--- /dev/null
+++ b/examples/richtextbox/richtextbox.code-workspace
@@ -0,0 +1,12 @@
+{
+	"folders": [
+		{
+			"path": "."
+		}
+	],
+	"settings": {
+		"d.projectImportPaths": [
+			"..\\..\\..\\dfl\\source"
+		]
+	}
+}
\ No newline at end of file
diff --git a/examples/richtextbox/shell.bat b/examples/richtextbox/shell.bat
new file mode 100644
index 0000000..49ab56b
--- /dev/null
+++ b/examples/richtextbox/shell.bat
@@ -0,0 +1,3 @@
+set dmd_path=c:\d\dmd2\windows
+set dmc_path=c:\dmc\dm
+cmd
diff --git a/examples/richtextbox/source/richtextbox_sample.d b/examples/richtextbox/source/richtextbox_sample.d
new file mode 100644
index 0000000..19f95b4
--- /dev/null
+++ b/examples/richtextbox/source/richtextbox_sample.d
@@ -0,0 +1,205 @@
+import dfl;
+import std.conv;
+
+version(Have_dfl) // For DUB.
+{
+}
+else
+{
+	pragma(lib, "dfl.lib");
+}
+
+class MainForm : Form
+{
+	private RichTextBox _textbox1;
+	private ToolBar _toolBar;
+
+	this()
+	{
+		// Form setting
+		this.text = "RichTextBox sample";
+		this.size = Size(800,400);
+		
+		// ToolBar setting
+		_toolBar = new ToolBar;
+		_toolBar.parent = this;
+		_toolBar.dock = DockStyle.TOP;
+
+		ToolBarButton button1 = new ToolBarButton("Bold");
+		_toolBar.buttonClick ~= (ToolBar tb, ToolBarButtonClickEventArgs e) {
+			if (e.button is button1)
+				_textbox1.selectionBold = !_textbox1.selectionBold;
+		};
+		_toolBar.buttons.add(button1);
+
+		ToolBarButton button2 = new ToolBarButton("UnderLine");
+		_toolBar.buttonClick ~= (ToolBar tb, ToolBarButtonClickEventArgs e) {
+			if (e.button is button2)
+				_textbox1.selectionUnderline = !_textbox1.selectionUnderline;
+		};
+		_toolBar.buttons.add(button2);
+
+		ToolBarButton button3 = new ToolBarButton("Font");
+		_toolBar.buttonClick ~= (ToolBar tb, ToolBarButtonClickEventArgs e) {
+			if (e.button is button3)
+			{
+				auto fontDialog = new FontDialog;
+				DialogResult dr = fontDialog.showDialog();
+				if (dr == DialogResult.OK)
+					_textbox1.selectionFont = fontDialog.font;
+			}
+		};
+		_toolBar.buttons.add(button3);
+
+		ToolBarButton button4 = new ToolBarButton("BaseUp");
+		_toolBar.buttonClick ~= (ToolBar tb, ToolBarButtonClickEventArgs e) {
+			if (e.button is button4)
+			{
+				if (_textbox1.selectionCharOffset <= 0)
+					_textbox1.selectionCharOffset = 72;
+				else
+					_textbox1.selectionCharOffset = 0;
+			}
+		};
+		_toolBar.buttons.add(button4);
+
+		ToolBarButton button5 = new ToolBarButton("BaseDown");
+		_toolBar.buttonClick ~= (ToolBar tb, ToolBarButtonClickEventArgs e) {
+			if (e.button is button5)
+			{
+				if (_textbox1.selectionCharOffset >= 0)
+					_textbox1.selectionCharOffset = -72;
+				else
+					_textbox1.selectionCharOffset = 0;
+			}
+		};
+		_toolBar.buttons.add(button5);
+
+		ToolBarButton buton6 = new ToolBarButton("F.Color");
+		_toolBar.buttonClick ~= (ToolBar tb, ToolBarButtonClickEventArgs e) {
+			if (e.button is buton6)
+			{
+				auto colorDialog = new ColorDialog;
+				DialogResult dr = colorDialog.showDialog();
+				if (dr == DialogResult.OK)
+					_textbox1.selectionColor = colorDialog.color;
+			}
+		};
+		_toolBar.buttons.add(buton6);
+
+		ToolBarButton button7 = new ToolBarButton("B.Color");
+		_toolBar.buttonClick ~= (ToolBar tb, ToolBarButtonClickEventArgs e) {
+			if (e.button is button7)
+			{
+				auto colorDialog = new ColorDialog;
+				DialogResult dr = colorDialog.showDialog();
+				if (dr == DialogResult.OK)
+					_textbox1.selectionBackColor = colorDialog.color;
+			}
+		};
+		_toolBar.buttons.add(button7);
+
+		ToolBarButton button8 = new ToolBarButton("^X");
+		_toolBar.buttonClick ~= (ToolBar tb, ToolBarButtonClickEventArgs e) {
+			if (e.button is button8)
+			{
+				_textbox1.selectionSuperscript = !_textbox1.selectionSuperscript;
+			}
+		};
+		_toolBar.buttons.add(button8);
+
+		ToolBarButton button9 = new ToolBarButton("_X");
+		_toolBar.buttonClick ~= (ToolBar tb, ToolBarButtonClickEventArgs e) {
+			if (e.button is button9)
+			{
+				_textbox1.selectionSubscript = !_textbox1.selectionSubscript;
+			}
+		};
+		_toolBar.buttons.add(button9);
+
+		ToolBarButton button10 = new ToolBarButton("GetText");
+		_toolBar.buttonClick ~= (ToolBar tb, ToolBarButtonClickEventArgs e) {
+			if (e.button is button10)
+			{
+				msgBox(_textbox1.selectedText);
+			}
+		};
+		_toolBar.buttons.add(button10);
+
+		ToolBarButton button11 = new ToolBarButton("InsText");
+		_toolBar.buttonClick ~= (ToolBar tb, ToolBarButtonClickEventArgs e) {
+			if (e.button is button11)
+			{
+				_textbox1.selectedText = "[Insert Text]";
+			}
+		};
+		_toolBar.buttons.add(button11);
+
+		ToolBarButton buton12 = new ToolBarButton("GetRtf");
+		_toolBar.buttonClick ~= (ToolBar tb, ToolBarButtonClickEventArgs e) {
+			if (e.button is buton12)
+			{
+				static if (1)
+				{
+					string rtf = _textbox1.selectedRtf;
+				}
+				else
+				{
+					string rtf = _textbox1.rtf;
+				}
+				msgBox(rtf);
+
+				static if (0)
+				{
+					_textbox1.rtf = rtf;
+				}
+			}
+		};
+		_toolBar.buttons.add(buton12);
+
+		ToolBarButton button13 = new ToolBarButton("GetSelNum");
+		_toolBar.buttonClick ~= (ToolBar tb, ToolBarButtonClickEventArgs e) {
+			if (e.button is button13)
+			{
+				msgBox(to!string(_textbox1.selectionLength));
+			}
+		};
+		_toolBar.buttons.add(button13);
+
+		ToolBarButton button14 = new ToolBarButton("SetSel(5)");
+		_toolBar.buttonClick ~= (ToolBar tb, ToolBarButtonClickEventArgs e) {
+			if (e.button is button14)
+			{
+				_textbox1.selectionLength = 5;
+			}
+		};
+		_toolBar.buttons.add(button14);
+
+		// RichTextBox setting
+		_textbox1 = new RichTextBox();
+		_textbox1.dock = DockStyle.FILL;
+		_textbox1.font = new Font(_textbox1.font.name, 14f);
+		_textbox1.multiline = true;
+		_textbox1.scrollBars = RichTextBoxScrollBars.FORCED_VERTICAL;
+		// _textbox1.acceptsReturn = true; // true: Enables RETURN key.
+		_textbox1.acceptsTab = true; // false: Disables TAB key.
+									 // true: Enables TAB key. But be changed focus only
+									 //       because one line textbox is not able to input TAB char.
+		_textbox1.wordWrap = false; // false: Do not send words that span the right edge to the next line.
+		_textbox1.text = "Hello.\nhttp://g/ <- click\nこんにちは。";
+		_textbox1.linkClicked ~= (RichTextBox sender, LinkClickedEventArgs e) {
+			msgBox(e.linkText);
+		};
+		_textbox1.parent = this;
+	}
+}
+
+static this()
+{
+	// Application.enableVisualStyles();
+}
+
+void main()
+{
+	Application.run(new MainForm());
+}