Unity3d 自动清除 Placeholder(default text)

public class Test : MonoBehaviour{    private string _default = "name";    private string _player_name = "";    private string _tooltip = "player_name_field";    private void OnGUI()    {        GUI.BeginGroup(new Rect(0, 0, 200, 30), new GUIContent("", _tooltip));        _player_name = GUI.TextField(new Rect(0, 0, 200, 30), _player_name);        GUI.EndGroup();        if (UnityEngine.Event.current.type == EventType.Repaint)        {            if (GUI.tooltip == _tooltip)            {                if (_player_name == _default) _player_name = "";            }            else            {                if (_player_name == "") _player_name = _default;            }        }    }}

see also:  http://answers.unity3d.com/questions/215808/clear-textfield-from-default-string.html