Flex 3：单击按钮时将焦点放在文本框上

问题描述

|| 快速背景。我有一系列可编辑的文本区域，我希望能够在其中单击按钮添加一个变量。 如果单击按钮，则文本区域失去焦点，因此我无法编写将变量添加到哪个文本区域的代码。谁能想到一种专注于文本框，插入变量然后允许用户进行键入的方法。 我不确定这是部分实现还是完全实现，但是任何帮助将不胜感激。我一直在尝试使用setFocus函数，以使其无法成功运行。 这是我的代码片段：

public function addFirstName(myText:string):void{
    myText = myText + \"<<firstname>>\";
}

<mx:TextArea id=\"txt1\" change=\"text1=txt1.text\" text=\"{text3}\" editable=\"true\"/>
<mx:TextArea id=\"txt2\" change=\"text2=txt2.text\" text=\"{text2}\" editable=\"true\"/>
<mx:Button label=\"Insert First Name\" click=\"addFirstName(focusedtextarea)\"/>

它是我专注的文本区域部分 提前致谢！     

解决方法

        使用聚焦事件编写一些代码，以存储需要更改的文本区域。概念上是这样的：

var textAreaToBeChanged : TextArea;

protected function onTextAreaLoseFocus(event:FocusEvent):void{
 // I\'m pretty sure Target is the right property to use here; but didn\'t test
 textAreaToBeChanged = target;
}

稍后在您的MXML中，添加事件侦听器。

<mx:TextArea id=\"txt1\" change=\"text1=txt1.text\" text=\"{text3}\" editable=\"true\" focusOut=\"{onTextAreaLoseFocus(event)}\"/>
<mx:TextArea id=\"txt2\" change=\"text2=txt2.text\" text=\"{text2}\" editable=\"true\" focusOut=\"{onTextAreaLoseFocus(event)}\"/>

    ,        排序！

public var textAreaToBeChanged : Object;
public var textposition:int

        //when leaving focus on a textbox,record the textarea and text position. If a button is clicked to add a variable,it needs to be added at this position
        protected function onTextAreaLoseFocus(event:FocusEvent):void{
            textAreaToBeChanged = event.target;
            textposition = textAreaToBeChanged.caretIndex;  
        }

        //split the text from the recent textbox at the position the cursor has just been. The restructure the text with the firstname variable in the middle.
        public function addFirstName():void{
            var firstbit:String = textAreaToBeChanged.text.substr(0,textposition);
            var myString:String = firstbit;

            myString = myString + firstnameVar;

            var lastbit:String = textAreaToBeChanged.text.substr(textposition);
            myString = myString + lastbit;
            textAreaToBeChanged.text = myString;
            //set the focus back to the textarea.
            textAreaToBeChanged.setFocus();
            //place the cursor after the variable we just added.
            textAreaToBeChanged.setSelection(textposition + firstnameVar.length,textposition + firstnameVar.length);
        }

和MXML：

<mx:TextArea id=\"txt1\" change=\"text1=txt1.text\" text=\"{text3}\" editable=\"true\" focusOut=\"{onTextAreaLoseFocus(event)}\"/>
<mx:TextArea id=\"txt2\" change=\"text2=txt2.text\" text=\"{text2}\" editable=\"true\" focusOut=\"{onTextAreaLoseFocus(event)}\"/>
<mx:Button label=\"Insert First Name\" click=\"addFirstName()\"/>