Full code after the jump.

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2008/01/30/copying-text-to-the-operating-system-clipboard-in-flex/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">
 
    <mx:Script>
        <![CDATA[
            import mx.controls.Alert;
 
            private function button_click():void {
                System.setClipboard(richTextEditor.text);
                Alert.show("Done");
            }
        ]]>
    </mx:Script>
 
    <mx:ApplicationControlBar dock="true">
        <mx:Button id="button"
                label="Copy text to clipboard"
                toolTip="Click here to copy the contents of the RichTextEditor control to the OS clipboard."
                click="button_click();" />
    </mx:ApplicationControlBar>
 
    <mx:RichTextEditor id="richTextEditor"
            text="The quick brown fox jumped over the lazy dog."
            width="100%"
            height="100%" />
 
</mx:Application>

View source is enabled in the following example.

 

Full code after the jump.

View MXML

<?xml version="1.0" encoding="utf-8"?>
<!-- http://blog.flexexamples.com/2007/12/07/converting-an-imagesnapshot-object-into-a-base-64-encoded-string-in-flex-3/ -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml"
        layout="vertical"
        verticalAlign="middle"
        backgroundColor="white">

    <mx:Script>
        <![CDATA[
            import flash.events.FocusEvent;
            import flash.system.System;
            import mx.graphics.ImageSnapshot;

            private function button_click(evt:MouseEvent):void {
                var ohSnap:ImageSnapshot = ImageSnapshot.captureImage(img);
                textArea.text = ImageSnapshot.encodeImageAsBase64(ohSnap);
            }

            private function textArea_focusIn(evt:FocusEvent):void {
                textArea.setSelection(0, textArea.text.length);
            }
        ]]>
    </mx:Script>

    <mx:ApplicationControlBar dock="true">
        <mx:Button label="Capture and encode"
                click="button_click(event);" />
    </mx:ApplicationControlBar>

    <mx:Form>
        <mx:FormItem label="source:">
            <mx:Image id="img"
                    source="@Embed('images/flex_logo.jpg')" />
        </mx:FormItem>
        <mx:FormItem label="Base64:">
            <mx:TextArea id="textArea"
                    editable="false"
                    showScrollTips="true"
                    width="320"
                    height="160"
                    focusIn="textArea_focusIn(event);" />
        </mx:FormItem>
        <mx:FormItem>
            <mx:Button label="Copy to clipboard"
                    enabled="{textArea.text.length > 0}"
                    click="System.setClipboard(textArea.text);" />
        </mx:FormItem>
    </mx:Form>

</mx:Application>

View source is enabled in the following example.