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// I am beginner on C#, i wish to get the data from DB, the put it into the datagrid, i am using wpf (C#), the program basically is able to run but i cannot return the result dynamically, instead hard coded i use here, so can give me some of the idea how to return the result dynamically, pls refer the comment inside the data file

//Main file

using System;
using System.Data;
using System.IO;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Navigation;

using Microsoft.Windows.Controls;

namespace testDG
{
    public partial class Window1
    {
        //local variables


        public Window1()
        {
            this.InitializeComponent();

            dg1.ItemsSource = data.GetCountryData();

        }

    }

}

//data file

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using MySql.Data;
using MySql.Data.MySqlClient;

namespace testDG
{
    public class data
    {
        //define property
        public string Code {get; set;}
        public string Country { get; set; }


        public data(string cd, string ct)
        {
            this.Code = cd;
            this.Country = ct;
        }

        public static List<data> GetCountryData()
        {

// when i code "new data[intVar]", it prompt me to use const var, instead of local var, but i will count the DB only can know got how many records, so const is impossible right? then "new data[4]{ using loop here }", it's prompt me invalid to use loop at here, so any other ways i can return the value dynamically? Pls help..thx


            return new List<data>(new data[4]
            {
                new data("1", "Malaysia"),
                new data("2", "HK"),
                new data("3", "China"),
                new data("4", "Singapore")

            });


        }

    }
}

Posted 21-Nov-09 2:04am

falconlee

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4 solutions

Solution 1

You instantiate List with 4 storage slots, then you attempt to fill the 2nd through 5th slots?

Posted 21-Nov-09 9:06am

Oakman

Solution 2

Actually the 4 storage slot that u seen is just a dummy data, to test whether the program is able to run or not. What i plans to do is make the size dynamic and data display also dynamic...So, does it possible?

Posted 21-Nov-09 9:18am

falconlee

Solution 4

Oh, really thanks for your help, i am successfully solve it..thx thx

Posted 21-Nov-09 9:45am

falconlee

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This content, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

AspDotNetDev · Accepted Answer · 2009-11-21T09:19:00

Seems you are having problems with lists and loops. First of all, you are using a collection initializer, which is only meant to initialize collections with a constant number of elements. To create a list of variable size, use this syntax:

C#

// Create an empty list.
List<data> myData = new List<data>();

Then just fill the list with data and it will dynamically resize according to your space requirements:

C#

// Fill the list with data.
for(int i = 0; i < GetMax(); i++)
{
	myData.Add(GetData(i));
}

The GetMax and GetData methods can be defined however you like. And they don't need to be methods... I just made them methods to make it clear that anything could go there. Here is an example of how they could be declared:

C#

// Get the size of the list.
public int GetMax() { return 4; }

// Get the data for each index in the list.
public data GetData(int index)
{
	switch(i)
	{
		case 0: return new data("1", "Malaysia");
		case 1: return new data("2", "HK");
		case 2: return new data("3", "China");
		case 3: return new data("4", "Singapore");
		default: throw new Exception("Invalid");
	}
}

List generic

4 solutions

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Solution 2

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Solution 4

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List generic

4 solutions

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