ajax jsonp 200 怎么到error去了,jquery ajax 200 OK JSON.ParseError

我有一个控件,它有一个文本框,当它的内容发生变化时,会使这个

javascript函数变得棘手：

page参数是document.URL,因为控件没有附加.asxc页面,fieldValue是文本框的值.

function UpdateFieldsOnListSelection(page,fieldValue) {

$.ajax({

type: "POST",url: page + "/IsSelectedListPictureLibrary",data: { "libraryInfo": fieldValue },contentType: "application/json; charset=utf-8",dataType: "json",success: function (data) {

alert("Success!");

},error: function (jqXHR,textStatus,errorThrown) {

alert("jqXHR: " + jqXHR.status + "\ntextStatus: " + textStatus + "\nerrorThrown: " + errorThrown);

}

});

};

它不断抛出这个错误：

jqXHR: 200

textStatus: parsererror

errorThrown: SyntaxError: JSON.parse: unexpected character

IsSelectedListPictureLibrary的代码：

[WebMethod]

public static bool IsSelectedListPictureLibrary(string libraryInfo)

{

if (string.IsNullOrEmpty(libraryInfo)) return false;

var common = new Utility();

var storedLibraryInfo = common.GetStoredLibraryInfo(libraryInfo);

if (storedLibraryInfo == null) return false;

var web = SPContext.Current.Site.OpenWeb(storedLibraryInfo.WebId);

var spList = web.Lists[storedLibraryInfo.LibraryId];

if (spList.BaseTemplate == SPListTemplateType.PictureLibrary)

{

web.Dispose();

return true;

}

web.Dispose();

return false;

}

我已经尝试将ajax中的json更改为jsonp,但发生了同样的错误.

我尝试改变数据格式.

有任何想法吗？