-
Data Grid
- Overview
-
Data Binding
-
Paging and Scrolling
-
Editing
-
Grouping
-
Filtering and Sorting
- Focused Row
-
Row Drag & Drop
-
Selection
-
Columns
- State Persistence
-
Appearance
-
Templates
-
Data Summaries
-
Master-Detail
-
Export to PDF
-
Export to Excel
-
Adaptability
- Keyboard Navigation
-
Pivot Grid
- Overview
-
Data Binding
-
Field Chooser
-
Features
-
Export to Excel
-
Tree List
- Overview
-
Data Binding
- Sorting
- Paging
-
Editing
- Node Drag & Drop
- Focused Row
-
Selection
-
Filtering
-
Column Customization
- State Persistence
- Adaptability
- Keyboard Navigation
-
Scheduler
- Overview
-
Data Binding
-
Views
-
Features
- Virtual Scrolling
-
Grouping
-
Customization
- Adaptability
-
Html Editor
-
Chat
-
Diagram
- Overview
-
Data Binding
-
Featured Shapes
-
Custom Shapes
-
Document Capabilities
-
User Interaction
- UI Customization
- Adaptability
-
Charts
- Overview
-
Data Binding
-
Area Charts
-
Bar Charts
- Bullet Charts
-
Doughnut Charts
-
Financial Charts
-
Line Charts
-
Pie Charts
-
Point Charts
-
Polar and Radar Charts
-
Range Charts
-
Sparkline Charts
-
Tree Map
-
Funnel and Pyramid Charts
- Sankey Chart
-
Combinations
-
More Features
-
Export
-
Selection
-
Tooltips
-
Zooming
-
-
Gantt
- Overview
-
Data
-
UI Customization
- Strip Lines
- Export to PDF
- Sorting
-
Filtering
-
Reporting
- AI-powered Extensions
-
Interaction
-
Report Types
-
Data binding
-
Real-life Reports
-
Layout Features
-
Report Controls
-
Web-specific Features
-
Rich Text Editor
- Overview
- Load/Save
- Document Protection
-
Templates
- Autocorrect
-
Customization
- Simple View
-
Spreadsheet
- Overview
-
Open a Document
- Export And Printing
-
Features
-
UI Customization
-
Gauges
- Overview
-
Data Binding
-
Bar Gauge
-
Circular Gauge
-
Linear Gauge
-
Navigation
- Overview
- Accordion
-
Menu
- Multi View
-
Drawer
-
Tab Panel
-
Tabs
-
Toolbar
- Pagination
-
Tree View
- Right-to-Left Support
-
Layout
-
Tile View
- Splitter
-
Gallery
- Scroll View
- Resizable
-
-
Editors
- Overview
- Autocomplete
-
Calendar
- Check Box
- Color Box
- Date Box
-
Date Range Box
-
Drop Down Box
-
Number Box
-
Select Box
- Switch
-
Tag Box
- Text Area
- Text Box
- Validation
- Custom Text Editor Buttons
- Right-to-Left Support
- Editor Appearance Variants
-
Forms and Multi-Purpose
- Overview
- Button Group
- Field Set
-
Filter Builder
-
Form
- Radio Group
-
Range Selector
- Numeric Scale (Lightweight)
- Numeric Scale
- Date-Time Scale (Lightweight)
- Date-Time Scale
- Logarithmic Scale
- Discrete scale
- Custom Formatting
- Use Range Selection for Calculation
- Use Range Selection for Filtering
- Image on Background
- Chart on Background
- Customized Chart on Background
- Chart on Background with Series Template
- Range Slider
- Slider
-
Sortable
-
File Management
-
File Manager
- Overview
-
File System Types
-
Customization
-
File Uploader
-
-
Actions and Lists
-
Maps
- Overview
-
Map
-
Vector Map
-
Dialogs and Notifications
-
Localization
Tree List - Load Data on Demand
The TreeList can load a remote dataset dynamically as a user expands nodes. The dataset must have a plain structure.
If you have technical questions, please create a support ticket in the DevExpress Support Center.
@(Html.DevExtreme().TreeList()
.ID("treelist")
.DataSource(new JS("treeList_dataSource"))
.KeyExpr("id")
.ParentIdExpr("parentId")
.HasItemsExpr("hasItems")
.ShowBorders(true)
.RemoteOperations(r => r.Filtering(true))
.Columns(columns => {
columns.Add()
.DataField("name");
columns.Add()
.DataField("size")
.CustomizeText("treeList_size_customizeText")
.Width(100);
columns.Add()
.DataField("createdDate")
.DataType(GridColumnDataType.Date)
.Width(150);
columns.Add()
.DataField("modifiedDate")
.DataType(GridColumnDataType.Date)
.Width(150);
})
.RootValue("")
)
<script>
function treeList_size_customizeText(e) {
if(e.value !== null) {
return Math.ceil(e.value / 1024) + " KB";
}
}
var treeList_dataSource = {
load: function(options) {
return $.ajax({
url: "@Url.Content("~/api/TreeListData")",
dataType: "json",
data: { parentIds: options.parentIds.join(",") }
}).then((result) => ({
data: result
}));
}
};
</script>
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using Microsoft.AspNetCore.Mvc;
using DevExtreme.NETCore.Demos.Models.SampleData;
namespace DevExtreme.NETCore.Demos.Controllers {
public class TreeListController : Controller {
public ActionResult LoadDataOnDemand() {
return View();
}
}
}
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using System;
using System.Linq;
using System.Net.Http;
using System.IO;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Hosting;
namespace DevExtreme.NETCore.Demos.Controllers.ApiControllers {
[Route("api/[controller]")]
public class TreeListDataController : Controller {
IWebHostEnvironment _webHostEnvironment;
public TreeListDataController(IWebHostEnvironment webHostEnvironment) {
_webHostEnvironment = webHostEnvironment;
}
[HttpGet]
public object Get(string parentIds) {
var parents = string.IsNullOrEmpty(parentIds) ? new[] { "" } : parentIds.Split(',');
#if PUBLISH
var rootPath = Path.Combine(_webHostEnvironment.ContentRootPath, "Sources");
#else
var rootPath = _webHostEnvironment.ContentRootPath;
#endif
var childNodes = parents.SelectMany(parentId => {
var parentPath = String.IsNullOrEmpty(parentId) ? rootPath : Path.Combine(rootPath, parentId);
return Directory.EnumerateFileSystemEntries(parentPath);
})
.Where(path => Path.GetFullPath(path).StartsWith(rootPath))
.Select(path => {
var fileInfo = new FileInfo(path);
var isDirectory = System.IO.File.GetAttributes(path).HasFlag(FileAttributes.Directory);
var parentId = Path.GetDirectoryName(path.Substring(rootPath.Length + 1));
return new {
id = Path.Combine(parentId, Path.GetFileName(path)),
parentId,
#if PUBLISH
name = Path.GetFileNameWithoutExtension(path),
#else
name = Path.GetFileName(path),
#endif
modifiedDate = fileInfo.LastWriteTime,
createdDate = fileInfo.CreationTime,
size = isDirectory ? (long?)null : fileInfo.Length,
isDirectory,
hasItems = isDirectory && Directory.EnumerateFileSystemEntries(path).Count() > 0
};
})
.Where(i => i.name != "bin" && i.name != "obj" && i.name != "packages" && i.name.Length > 0 && !i.name.StartsWith("."))
.OrderByDescending(i => i.isDirectory)
.ThenBy(i => i.name);
return childNodes;
}
}
}
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#treelist {
max-height: 440px;
}
This feature requires client- and server-side configurations. To configure the client-side part, do the following:
-
Send an expanded node's ID to the server
For this, implement the CustomStore's load function. In this demo, we do it in the dataSource configuration object. -
Delegate filtering to the server
Set the remoteOperations.filtering property to true. -
Specify the data field that defines whether the node has children
Use the hasItemsExpr property to set this data field.
Server-side implementation is available in the ASP.NET Core and ASP.NET MVC versions of this demo under the TreeListDataController.cs
tab.
This demo uses a simple data bind technique that is useful for data display purposes only. When a user clicks a node, TreeList receives a JSON object from the server, which is based on the parentIds property value. This technique does not support the built-in data process operations in TreeList on the server.
If your project needs to process data, do one of the following instead:
- Implement a custom data source. See the Custom Data Source demo.
- Use the DevExtreme.AspNet.Data extension as shown in the Web API Service demo.