IDataStore<TModel>.FindIndex(Predicate<TModel> predicate) Method

.NET Standard 2.x

Returns the index number of the next row in the primary buffer of the DataStore in which data meets the condition specified by the expression.

Namespace: DWNet.Data

Assembly: DWNet.Data.dll

Syntax

int FindIndex(Predicate<TModel> predicate);

Parameters

predicate Predicate<TModel>

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

Returns

System.Int

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

Returns -1 if no row is found.

Remarks

When multiple rows satisfy the condition, the first row will be returned.

The index number starts from 0 which is consistent with C#.

Examples

The following code example demonstrates how to return the index number of the department record using a Predicate object.

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

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

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

        public void Example()
        {
            // 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 => d.Departmentid < 3);

            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
            */
        }
    }
}

Example Refer To

Model Class: D_Department
DataWindow File: d_department