【发布时间】：2021-01-25 06:31:46
【问题描述】：
我是 Datatables 的 AJAX 调用新手。我需要为数千条记录实现服务器端处理。我正在学习一个教程，但我在某处对服务器端处理感到困惑。
我在尝试从数据源呈现数据时遇到错误。让我发布所有相关代码，希望你能帮助我找出我哪里出错了。由于我是 Datatables 和 Ajax 的新手，我将感谢更多的示例、文本答案以及代码或链接到在 ASP.NET CORE 3.1 中演示服务器端处理的教程。
感谢您的宝贵时间和帮助。
注意。我从教程中获取了实现和配置，并尝试对其进行自定义。
下面是 HTML 表格及其模型：
@model IEnumerable<StudentApplications>
<table id="custom-datatable" class="mb-5 display table table-bordered" style="width:100%">
<thead>
<tr>
<th>
@Html.DisplayNameFor(model => model.ApplicationId)
</th>
<th>
@Html.DisplayNameFor(model => model.Firstname)
</th>
<th>
@Html.DisplayNameFor(model => model.Surname)
</th>
<th>
@Html.DisplayNameFor(model => model.ApplicationFor)
</th>
<th>
@Html.DisplayNameFor(model => model.SubmissionDate)
</th>
<th></th>
</tr>
</thead>
<tfoot>
<tr>
<th>
@Html.DisplayNameFor(model => model.ApplicationId)
</th>
<th>
@Html.DisplayNameFor(model => model.Firstname)
</th>
<th>
@Html.DisplayNameFor(model => model.Surname)
</th>
<th>
@Html.DisplayNameFor(model => model.ApplicationFor)
</th>
<th>
@Html.DisplayNameFor(model => model.SubmissionDate)
</th>
<th></th>
</tr>
</tfoot>
</table>
以下是将 HTML 表初始化为数据表的 javascript 文件和一些配置：
$(document).ready(function () {
$('#custom-datatable').DataTable({
// Design Assets
stateSave: true,
autoWidth: true,
// ServerSide Setups
processing: true,
serverSide: true,
// Paging Setups
paging: true,
// Searching Setups
searching: { regex: true },
// Ajax Filter
ajax: {
url: "/myapplications/data",
type: "POST",
contentType: "application/json",
dataType: "json",
data: function (d) {
return JSON.stringify(d);
}
},
// Columns Setups
columns: [
{ data: "ApplicationId" },
{ data: "Firstname" },
{ data: "Surname" },
{ data: "ApplicationFor" },
{ data: "SubmissionDate" }
//// For Student.Id
//{ "data": "applicationId", "name": "ApplicationId" },
//// For Student.Firstname
//{ "data": "firstname", "name": "Firstname" },
//// For Student.Surname
//{ "data": "surname", "name": "Surname" },
//// For Student.ApplicationFor
//{ "data": "applicationFor", "name": "ApplicationFor" },
//// For Student.SubmissionDate
//{ "data": "submissionDate", "name": "SubmissionDate" }
],
// Column Definitions
columnDefs: [
{ targets: "no-sort", orderable: false },
{ targets: "no-search", searchable: false },
{
targets: "trim",
render: function (data, type, full, meta) {
if (type === "display") {
data = strtrunc(data, 10);
}
return data;
}
},
{ targets: "date-type", type: "date-eu" },
{
targets: 10,
data: null,
orderable: false
},
]
});
});
以下是获取数据的方法：
// loading datatable
[HttpPost]
[Route("myapplications/data")]
public async Task<IActionResult> Data([FromBody] DtParameters dtParameters)
{
searchBy = dtParameters.Search?.Value;
// if we have an empty search then just order the results by Id ascending
var orderCriteria = "ApplicationId";
var orderAscendingDirection = true;
if (dtParameters.Order != null)
{
// in this example we just default sort on the 1st column
orderCriteria = dtParameters.Columns[dtParameters.Order[0].Column].Data;
orderAscendingDirection = dtParameters.Order[0].Dir.ToString().ToLower() == "asc";
}
var result = context.AspNetStudentApplications.AsQueryable();
if (!string.IsNullOrEmpty(searchBy))
{
result = result.Where(r => r.ApplicationId != null && r.ApplicationId.ToUpper().Contains(searchBy.ToUpper()) ||
r.Firstname != null && r.Firstname.ToUpper().Contains(searchBy.ToUpper()) ||
r.Surname != null && r.Surname.ToUpper().Contains(searchBy.ToUpper()) ||
r.ApplicationFor != null && r.ApplicationFor.ToUpper().Contains(searchBy.ToUpper()) ||
r.SubmissionDate != null && r.SubmissionDate.ToUpper().Contains(searchBy.ToUpper()));
}
result = orderAscendingDirection ? result.OrderByDynamic(orderCriteria, DtOrderDir.Asc) : result.OrderByDynamic(orderCriteria, DtOrderDir.Desc);
// now just get the count of items (without the skip and take) - eg how many could be returned with filtering
var filteredResultsCount = await result.CountAsync();
var totalResultsCount = await context.AspNetStudentApplications.CountAsync();
return Json(new DtResult<StudentApplications>
{
Draw = dtParameters.Draw,
RecordsTotal = totalResultsCount,
RecordsFiltered = filteredResultsCount,
Data = await result
.Skip(dtParameters.Start)
.Take(dtParameters.Length)
.ToListAsync()
});
}
下面是 DtParameters 类和其他与 Datatables 相关的类：
/// <summary>
/// A full result, as understood by jQuery DataTables.
/// </summary>
/// <typeparam name="T">The data type of each row.</typeparam>
public class DtResult<T>
{
/// <summary>
/// The draw counter that this object is a response to - from the draw parameter sent as part of the data request.
/// Note that it is strongly recommended for security reasons that you cast this parameter to an integer, rather than simply echoing back to the client what it sent in the draw parameter, in order to prevent Cross Site Scripting (XSS) attacks.
/// </summary>
[JsonProperty("draw")]
public int Draw { get; set; }
/// <summary>
/// Total records, before filtering (i.e. the total number of records in the database)
/// </summary>
[JsonProperty("recordsTotal")]
public int RecordsTotal { get; set; }
/// <summary>
/// Total records, after filtering (i.e. the total number of records after filtering has been applied - not just the number of records being returned for this page of data).
/// </summary>
[JsonProperty("recordsFiltered")]
public int RecordsFiltered { get; set; }
/// <summary>
/// The data to be displayed in the table.
/// This is an array of data source objects, one for each row, which will be used by DataTables.
/// Note that this parameter's name can be changed using the ajax option's dataSrc property.
/// </summary>
[JsonProperty("data")]
public IEnumerable<T> Data { get; set; }
/// <summary>
/// Optional: If an error occurs during the running of the server-side processing script, you can inform the user of this error by passing back the error message to be displayed using this parameter.
/// Do not include if there is no error.
/// </summary>
[JsonProperty("error", NullValueHandling = NullValueHandling.Ignore)]
public string Error { get; set; }
public string PartialView { get; set; }
}
/// <summary>
/// The additional columns that you can send to jQuery DataTables for automatic processing.
/// </summary>
public abstract class DtRow
{
/// <summary>
/// Set the ID property of the dt-tag tr node to this value
/// </summary>
[JsonProperty("DT_RowId")]
public virtual string DtRowId => null;
/// <summary>
/// Add this class to the dt-tag tr node
/// </summary>
[JsonProperty("DT_RowClass")]
public virtual string DtRowClass => null;
/// <summary>
/// Add the data contained in the object to the row using the jQuery data() method to set the data, which can also then be used for later retrieval (for example on a click event).
/// </summary>
[JsonProperty("DT_RowData")]
public virtual object DtRowData => null;
/// <summary>
/// Add the data contained in the object to the row dt-tag tr node as attributes.
/// The object keys are used as the attribute keys and the values as the corresponding attribute values.
/// This is performed using using the jQuery param() method.
/// Please note that this option requires DataTables 1.10.5 or newer.
/// </summary>
[JsonProperty("DT_RowAttr")]
public virtual object DtRowAttr => null;
}
/// <summary>
/// The parameters sent by jQuery DataTables in AJAX queries.
/// </summary>
public class DtParameters
{
/// <summary>
/// Draw counter.
/// This is used by DataTables to ensure that the Ajax returns from server-side processing requests are drawn in sequence by DataTables (Ajax requests are asynchronous and thus can return out of sequence).
/// This is used as part of the draw return parameter (see below).
/// </summary>
public int Draw { get; set; }
/// <summary>
/// An array defining all columns in the table.
/// </summary>
public DtColumn[] Columns { get; set; }
/// <summary>
/// An array defining how many columns are being ordering upon - i.e. if the array length is 1, then a single column sort is being performed, otherwise a multi-column sort is being performed.
/// </summary>
public DtOrder[] Order { get; set; }
/// <summary>
/// Paging first record indicator.
/// This is the start point in the current data set (0 index based - i.e. 0 is the first record).
/// </summary>
public int Start { get; set; }
/// <summary>
/// Number of records that the table can display in the current draw.
/// It is expected that the number of records returned will be equal to this number, unless the server has fewer records to return.
/// Note that this can be -1 to indicate that all records should be returned (although that negates any benefits of server-side processing!)
/// </summary>
public int Length { get; set; }
/// <summary>
/// Global search value. To be applied to all columns which have searchable as true.
/// </summary>
public DtSearch Search { get; set; }
/// <summary>
/// Custom column that is used to further sort on the first Order column.
/// </summary>
public string SortOrder => Columns != null && Order != null && Order.Length > 0
? (Columns[Order[0].Column].Data +
(Order[0].Dir == DtOrderDir.Desc ? " " + Order[0].Dir : string.Empty))
: null;
/// <summary>
/// For Posting Additional Parameters to Server
/// </summary>
public IEnumerable<string> AdditionalValues { get; set; }
}
/// <summary>
/// A jQuery DataTables column.
/// </summary>
public class DtColumn
{
/// <summary>
/// Column's data source, as defined by columns.data.
/// </summary>
public string Data { get; set; }
/// <summary>
/// Column's name, as defined by columns.name.
/// </summary>
public string Name { get; set; }
/// <summary>
/// Flag to indicate if this column is searchable (true) or not (false). This is controlled by columns.searchable.
/// </summary>
public bool Searchable { get; set; }
/// <summary>
/// Flag to indicate if this column is orderable (true) or not (false). This is controlled by columns.orderable.
/// </summary>
public bool Orderable { get; set; }
/// <summary>
/// Search value to apply to this specific column.
/// </summary>
public DtSearch Search { get; set; }
}
/// <summary>
/// An order, as sent by jQuery DataTables when doing AJAX queries.
/// </summary>
public class DtOrder
{
/// <summary>
/// Column to which ordering should be applied.
/// This is an index reference to the columns array of information that is also submitted to the server.
/// </summary>
public int Column { get; set; }
/// <summary>
/// Ordering direction for this column.
/// It will be dt-string asc or dt-string desc to indicate ascending ordering or descending ordering, respectively.
/// </summary>
public DtOrderDir Dir { get; set; }
}
/// <summary>
/// Sort orders of jQuery DataTables.
/// </summary>
public enum DtOrderDir
{
Asc,
Desc
}
/// <summary>
/// A search, as sent by jQuery DataTables when doing AJAX queries.
/// </summary>
public class DtSearch
{
/// <summary>
/// Global search value. To be applied to all columns which have searchable as true.
/// </summary>
public string Value { get; set; }
/// <summary>
/// true if the global filter should be treated as a regular expression for advanced searching, false otherwise.
/// Note that normally server-side processing scripts will not perform regular expression searching for performance reasons on large data sets, but it is technically possible and at the discretion of your script.
/// </summary>
public bool Regex { get; set; }
}
我哪里弄错了？
@HMZ 实施，我看到空记录（下图）：
【问题讨论】：
-
请显示控制台错误而不是警报，并确保在服务器端包含任何异常。
-
@HMZ：我已经更新了问题并发布了第一次发生异常的位置
-
您需要一个自定义模型绑定器。我将发布一个工作示例。
-
@HMZ：我很期待。我真的很感谢你的时间
-
嗨@RussellChidhakwa，你能提供教程的链接吗
标签： jquery ajax asp.net-core datatables server-side