function gray()
{
  //取得插件截屏的 base64 串
  var strBase64 = AF.func("screenShot", "return=base64;range=control;type=png;isGray=true");
  //将 C# 规则的Base64改成 java/js规则的 Base64 (星号替换成斜杠)
  strBase64 = strBase64.replace(/\*/g, '\/');
  //拼装 css, 作为div容器的背景图
  var strStyle = 'data:image/png;base64,' + strBase64;
  document.getElementById('div_AF').style.backgroundImage="url('" +strStyle+ "')";
  //隐去插件
  AF.style.height = '1px';
  AF.style.width = '1px';
  //显示弹窗
  document.getElementById('box').style.display="block";
}