IDataStore.FindIndex<TModel>(Predicate<TModel> predicate, int start, int end, DwBuffer bufferType = DwBuffer.Primary) Method

.NET Standard 2.x

Generic method. Returns the index number of the next row in the DataStore in which data meets the criteria defined by Predicate. If both start and end parameters are set to -1, it indicates the search starts from the beginning to the end. The primary buffer is specified by default.

Namespace: DWNet.Data

Assembly: DWNet.Data.dll

Syntax

int FindIndex<TModel>(Predicate<TModel> predicate, int start, int end, DwBuffer bufferType = DwBuffer.Primary);

Type Parameters

TModel

The type of a model class that matches with the current DataObject.

Parameters

predicate System.Predicate<TModel>

A Predicate<TModel> that you want to use as the search criteria.

start System.Int32

The zero-based index number of the row from which the search starts.

If start is larger than end, it will do a backward search instead of forward search.

If it is negative, it starts from 0.

end System.Int32

The zero-based index number of the row at which the search ends.

If it is negative, it searches to the end.

bufferType DWNet.Data.DwBuffer

The buffer in which to find the row.

It is specified to the primary buffer by default.

Returns

System.Int32

Returns the zero-based index number of the row found.

Returns -1 if no row is found.

Examples

The following code example demonstrates how to return the index number of the department record using a Predicate<TModel> object and the start and end parameters.

using Appeon.ApiDoc.Models;
using DWNet.Data;
using System;

namespace Appeon.ApiDoc.IDataStoreExamples
{
    public class FindIndexExample
    {
        private readonly SchoolContext _context;

        public FindIndexExample(SchoolContext dataContext)
        {
            // Sets the data context
            _context = dataContext;
        }

        public void Example2()
        {
            // Instantiates a DataStore object with datawindow: d_department.
            var datastore = new DataStore("d_department", _context);

            datastore.Retrieve();

            // The first record in the Department table is found: 
            // departmentid=1, name=Engineering
            var findrow = datastore.FindIndex<D_Department>(d =>d.Departmentid < 3);

            Console.WriteLine("Department ID: {0}; Department Name: {1}",
                               datastore.GetItem<int>(findrow, "departmentid"),
                               datastore.GetItem<string>(findrow, "name"));

            // The second record in the Department table is found: 
            // departmentid=2, name=English
            // 1 indicates to find from the second row, -1 indicates to find through the end
            findrow = datastore.FindIndex<D_Department>
                                (d => d.Departmentid < 3, 1, -1);

            Console.WriteLine("Department ID: {0}; Department Name: {1}",
                               datastore.GetItem<int>(findrow, "departmentid"),
                               datastore.GetItem<string>(findrow, "name"));


            /*This code produces the following output:
             
            Department ID: 1; Department Name: Engineering
            Department ID: 2; Department Name: English
            */
        }
    }
}

Example Refer To

Model Class: D_Department
DataWindow File: d_department

Applies to

.NET Standard

2.x