Readme file added

Author: Gowtham-SF4769

README.md

@@ -1,2 +1,71 @@
 # How-to-apply-initial-multi-column-sorting-in-Flutter-DataTable-SfDataGrid
-This demo shows how to apply initial multi-column sorting in Flutter DataTable (SfDataGrid)
+
+In this article, we will show how to apply initial multi-column sorting in [Flutter DataTable](https://www.syncfusion.com/flutter-widgets/flutter-datagrid).
+
+Initialize the [SfDataGrid](https://pub.dev/documentation/syncfusion_flutter_datagrid/latest/datagrid/SfDataGrid-class.html) with the necessary properties. The DataGrid supports programmatic column sorting. You can manually define [SortColumnDetails](https://pub.dev/documentation/syncfusion_flutter_datagrid/latest/datagrid/SortColumnDetails-class.html) objects and add them to the [SfDataGrid.source.sortedColumns](https://pub.dev/documentation/syncfusion_flutter_datagrid/latest/datagrid/DataGridSource/sortedColumns.html) collection. The DataGrid then sorts the data based on the SortColumnDetails objects in this collection. By handling this in the [initState](https://api.flutter.dev/flutter/widgets/State/initState.html) method, you can define a multi-column sort order that is automatically applied when the DataGrid is first rendered.
+
+```dart
+  @override
+  void initState() {
+    super.initState();
+    employees = getEmployeeData();
+    employeeDataSource = EmployeeDataSource(employeeData: employees);
+    //Initial-multi-column-sorting
+    employeeDataSource.sortedColumns.addAll([
+      SortColumnDetails(
+        name: 'id',
+        sortDirection: DataGridSortDirection.ascending,
+      ),
+      SortColumnDetails(
+        name: 'name',
+        sortDirection: DataGridSortDirection.ascending,
+      ),
+    ]);
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return Scaffold(
+      appBar: AppBar(title: const Text('Syncfusion Flutter DataGrid')),
+      body: SfDataGrid(
+        source: employeeDataSource,
+        columnWidthMode: ColumnWidthMode.fill,
+        columns: <GridColumn>[
+          GridColumn(
+            columnName: 'id',
+            label: Container(
+              padding: EdgeInsets.all(16.0),
+              alignment: Alignment.center,
+              child: Text('ID'),
+            ),
+          ),
+          GridColumn(
+            columnName: 'name',
+            label: Container(
+              padding: EdgeInsets.all(8.0),
+              alignment: Alignment.center,
+              child: Text('Name'),
+            ),
+          ),
+          GridColumn(
+            columnName: 'designation',
+            label: Container(
+              padding: EdgeInsets.all(8.0),
+              alignment: Alignment.center,
+              child: Text('Designation', overflow: TextOverflow.ellipsis),
+            ),
+          ),
+          GridColumn(
+            columnName: 'salary',
+            label: Container(
+              padding: EdgeInsets.all(8.0),
+              alignment: Alignment.center,
+              child: Text('Salary'),
+            ),
+          ),
+        ],
+      ),
+    );
+  }
+```
+You can download this example on [GitHub](https://github.com/SyncfusionExamples/How-to-apply-initial-multi-column-sorting-in-Flutter-DataTable-SfDataGrid.git).