Flash / Flex / ActionScript/TextField/focus

Assigning Focus to a Text Field

 
package {
  import flash.display.Sprite;
  import flash.text.TextField;
  import flash.text.TextFieldType;
  import flash.events.MouseEvent;
  public class Main extends Sprite {
    public function Main(  ) {
      var field:TextField = new TextField(  );
      field.border = true;
      field.background = true;
      field.type = TextFieldType.INPUT;
      addChild(field);
      var button:Sprite = new Sprite(  );
      button.graphics.lineStyle(  );
      button.graphics.beginFill(0xFFFFFF);
      button.graphics.drawRect(0, 0, 100, 50);
      button.graphics.endFill(  );
      button.addEventListener(MouseEvent.CLICK, onClick);
      button.y = 100;
      addChild(button);
    }
    
    private function onClick(event:MouseEvent):void {
      stage.focus = TextField(getChildAt(0));
    }
    
  }
}

Setting the Insertion Point in a Text Field

 

package {
  import flash.display.Sprite;
  import flash.text.TextField;
  public class Main extends Sprite {
    public function Main(  ) {
      var field:TextField = new TextField(  );
    
        stage.focus = field;                  // Set the focus to the text field
        field.text = "this is example text";  // Set the text value
        field.setSelection(0, 0);
        
        
        trace(field.caretIndex);
        addChild(field);
    }
  }
}

To remove focus from a text field you should assign Stage.focus the null value

 
package {
  import flash.display.Sprite;
  import flash.text.TextField;
  import flash.text.TextFieldType;
  import flash.events.MouseEvent;
  public class Main extends Sprite {
    public function Main(  ) {
      var field:TextField = new TextField(  );
      field.border = true;
      field.background = true;
      field.type = TextFieldType.INPUT;
      addChild(field);
      var button:Sprite = new Sprite(  );
      button.graphics.lineStyle(  );
      button.graphics.beginFill(0xFFFFFF);
      button.graphics.drawRect(0, 0, 100, 50);
      button.graphics.endFill(  );
      button.addEventListener(MouseEvent.CLICK, onClick);
      button.y = 100;
      addChild(button);
    }
    
    private function onClick(event:MouseEvent):void {
      stage.focus = null;
    }
    
  }
}