Windows Phone tool kit bug

Windows phone tool kit 中PhoneTextBox控件有个bug,就是当从输入状态切换失去焦点时，再次进入输入状态时字体颜色会变浅，并且无法恢复。产生这个bug的原因是输入框的状态未及时改变回编辑状态。解决办法：

找到控件源码，在函数UpdateHintVisibility()中 ActualHintVisibility = Visibility.Collapsed;的后面添加Foreground = ForegroundBrushEdit;

即添加后的代码：

private void UpdateHintVisibility()
{
　　if (HintContent != null)
   {
     if (string.IsNullOrEmpty(Text))
     {
     　　ActualHintVisibility = Visibility.Visible;
        Foreground = ForegroundBrushInactive;
     }
     else
     {
       ActualHintVisibility = Visibility.Collapsed;
       Foreground = ForegroundBrushEdit;// Dokay add
     }
   }
}