如何解决json和web服务错误,返回null消息! [英] how to solve json and web service error , return null message !
问题描述
我在显示我的页面时出现问题,json在警告消息中返回null,webservice返回我的正常数据,但不显示在页面上
web服务(DirectoryService。 asmx)
公共 类 GetDirectory
继承 System.Web.Services.WebService
< WebMethod()> _
公共 功能 LoadData() As 字符串
' 列表(Of目录)()
System.Threading.Thread.Sleep( 500 )
Dim da As 新目录()
Dim dt As 新 Directories.DirectoriesDataTable
dt = da。读取( 3, Nothing , 1 , 5 )
Dim 序列化器 As 新 System.Web.Script.Serialization.JavaScriptSerializer()
Dim 行作为 新列表( 字典( 字符串,对象))()
Dim row As Dictionary( Of 字符串,对象)
对于 每个 dr As DataRow 在 dt.Rows
row = 新字典( 字符串 ,对象)()
对于 每个 col 作为 DataColumn 在 dt.Columns
row.Add(col.ColumnName,dr(col))
下一步
rows.Add(row)
下一步
返回 serializer.Serialize(rows)
结束 功能
*网络服务结果
< string xmlns = http://tempuri.org/ >
[{DirectoryID:1,DirectoryName:艺术家,Dir ectoryNameAr : الفنانون DirectoryImage: 41570.7052485995.jpg, AllowDisplay:真, 排序依据:2 CreatedOn: \ /日期(1382536533483)\ /},{ DirectoryID :2,目录名 : 开发 DirectoryNameAr: المطورون, DirectoryImage: 41571.6455421065.jpg, AllowDisplay:真, 排序依据:1, CreatedOn: \ /日期(1382617774857)\ / },{ DirectoryID :3,目录名 : 教师, DirectoryNameAr: المعلمين, DirectoryImage: 123123, AllowDisplay:真, 排序依据 :3, CreatedOn:空},{ DirectoryID:4 目录名: 脸, DirectoryNameAr: الفنانون, DirectoryImage: 41570.7052485995.jpg, AllowDisplay:真排序依据 :2,CreatedOn : \ /日期(1382536533483)\ / },{ DirectoryID :5,目录名 : 内绍, DirectoryNameAr: المطورون, DirectoryImage: 41571.6455421065.jpg,AllowDisplay:true,OrderBy:1,CreatedOn:\ / Date(1382617774857)\ /}]
< / string >
* Json在我的页面上(Loading.aspx)
< script src = js / jquery-1.6.4.min.js>< / script>
< script type = text / javascript>
var skiprows = 1 ;
$( document )。ready( function (){
fnBuildData() ;
$( #btnComments)。bind( 点击, function (){
fnBuildData() ;
返回 false ;
})
});
// $(window).scroll(function(){
// if($(window).scrollTop()== $(document).height() - $(window).height()){
// fnBuildData( );
// }
// });
function fnBuildData() {
$( #imgLoading)。show();
$ .ajax({
type: POST,
contentType: Application / json; charset = utf-8,
url:< span class =code-string> GetDirectory.asmx / LoadData,
data:' {}',
datatype: json,
成功: function (msg){
var nextrows =<%= getrows %> +1;
skiprows + = nextrows;
var cmntobject = $ .parseJSON(msg.d);
警报(cmntobject);
$( #imgLoading)。hide();
if (cmntobject.length< nextrows)
{$( < span class =code-string>#btnComments)。hide(); }
$ .each(cmntobject, function (index,cmnt){
$( #resultsTable)。append( < ; table>< tr>< td> DirectoryName:< / td>< td>
+ cmnt.DirectoryName + < / td>< / tr>< tr>< td> DirectoryNameAr:< / td>< td>
+ cmnt.DirectoryNameAr + < / td>< / tr>< tr>< td colspan ='2 'nowrap ='nowrap'>
+ cmnt.DirectoryID + < hr />< / td>< / tr>< / table>);
});
}
,
错误: function (){alert( ' 发生错误,请稍后再试。'); $( #imgLoading)。hide(); }
});
}
< / script>
* asp
< div id =resultsTable>
< / div>
< img id =imgLoadingalt =loadingsrc =images / loadingAnimation.gif/>
< asp:ImageButton ID =btnCommentsEnableViewState =false Width =90Height =90ClientIDMode =Staticrunat =serverImageUrl =〜/ images / loadmore.jpg/>
显示我的页面(loading.aspx)但返回消息(null)
我的问题在哪里?
< blockquote>( document )。ready( function (){
fnBuildData();
( #btnComments)。bind( 点击, function (){
fnBuildData();
return false ;
})
});
//
(window).scroll (function(){
// if(
i have aproblem when display my page with json return null in alert message , webservice return my normal data , but not display on page
web service (DirectoryService.asmx)
Public Class GetDirectory
Inherits System.Web.Services.WebService
<WebMethod()> _
Public Function LoadData() As String
'List(Of Directory)()
System.Threading.Thread.Sleep(500)
Dim da As New Directories()
Dim dt As New Directories.DirectoriesDataTable
dt = da.Read("3", Nothing, 1, 5)
Dim serializer As New System.Web.Script.Serialization.JavaScriptSerializer()
Dim rows As New List(Of Dictionary(Of String, Object))()
Dim row As Dictionary(Of String, Object)
For Each dr As DataRow In dt.Rows
row = New Dictionary(Of String, Object)()
For Each col As DataColumn In dt.Columns
row.Add(col.ColumnName, dr(col))
Next
rows.Add(row)
Next
Return serializer.Serialize(rows)
End Function
* web service result
<string xmlns="http://tempuri.org/">
[{"DirectoryID":1,"DirectoryName":"artist","DirectoryNameAr":"الفنانون","DirectoryImage":"41570.7052485995.jpg","AllowDisplay":true,"OrderBy":2,"CreatedOn":"\/Date(1382536533483)\/"},{"DirectoryID":2,"DirectoryName":"Developer","DirectoryNameAr":"المطورون","DirectoryImage":"41571.6455421065.jpg","AllowDisplay":true,"OrderBy":1,"CreatedOn":"\/Date(1382617774857)\/"},{"DirectoryID":3,"DirectoryName":"Teachers","DirectoryNameAr":"المعلمين","DirectoryImage":"123123","AllowDisplay":true,"OrderBy":3,"CreatedOn":null},{"DirectoryID":4,"DirectoryName":"face","DirectoryNameAr":"الفنانون","DirectoryImage":"41570.7052485995.jpg","AllowDisplay":true,"OrderBy":2,"CreatedOn":"\/Date(1382536533483)\/"},{"DirectoryID":5,"DirectoryName":"nesho","DirectoryNameAr":"المطورون","DirectoryImage":"41571.6455421065.jpg","AllowDisplay":true,"OrderBy":1,"CreatedOn":"\/Date(1382617774857)\/"}]
</string>
* Json on my page (Loading.aspx)
<script src="js/jquery-1.6.4.min.js"></script>
<script type="text/javascript">
var skiprows = 1;
$(document).ready(function () {
fnBuildData();
$("#btnComments").bind("click", function () {
fnBuildData();
return false;
})
});
//$(window).scroll(function () {
// if ($(window).scrollTop() == $(document).height() - $(window).height()) {
// fnBuildData();
// }
//});
function fnBuildData() {
$("#imgLoading").show();
$.ajax({
type: "POST",
contentType: "Application/json ; charset=utf-8",
url: "GetDirectory.asmx/LoadData",
data: '{}',
datatype: "json",
success: function (msg) {
var nextrows = <%= getrows%> +1;
skiprows += nextrows;
var cmntobject = $.parseJSON(msg.d);
alert(cmntobject);
$("#imgLoading").hide();
if (cmntobject.length < nextrows)
{ $("#btnComments").hide(); }
$.each(cmntobject, function (index, cmnt) {
$("#resultsTable").append("<table><tr><td>DirectoryName :</td><td>"
+ cmnt.DirectoryName + "</td></tr><tr><td> DirectoryNameAr : </td><td> "
+ cmnt.DirectoryNameAr + "</td></tr><tr><td colspan='2' nowrap='nowrap'>"
+ cmnt.DirectoryID + "<hr /></td></tr></table>");
});
}
,
error: function () { alert('Error occured , try later .'); $("#imgLoading").hide(); }
});
}
</script>
* asp
<div id="resultsTable">
</div>
<img id="imgLoading" alt="loading" src="images/loadingAnimation.gif" />
<asp:ImageButton ID="btnComments" EnableViewState="false" Width="90" Height="90" ClientIDMode="Static" runat="server" ImageUrl="~/images/loadmore.jpg" />
when display my page (loading.aspx) but it return message (null)
where is my problem ?
(document).ready(function () { fnBuildData();
("#btnComments").bind("click", function () { fnBuildData(); return false; }) }); //
(window).scroll(function () { // if (
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