Calling Win32 Api from C# - csharp

Though .Net classes are vast and versatile at time you will have to resort to Win32 API calls for accomplishing certain tasks.

The following code shows a simple example of invoking a Win32 api.

The best way to use Win32 apis is to encapsulate it in a class module.
The namespace for COM interop is System.Runtime.InteropServices.
The method name should have DllImport attribute specifying the name of the dll. Here the dll is user32. Other dlls are Gdi and Kernel.

using System;
using System.Collection.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Data.SqlClient;

namespace WindowsApplication1
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void cmdtam_Klik(object sender, EventArgs e)
{
string cstr;
cstr = "data source=jery;initial catalog=latihan;uid=sa;pwd=sri";
SqlConnection con1 = new SqlConnection(cstr);
con1.Open();
SqlCommand com1 = new SqlCommand();
com1.Connection = con1;
com1.CommandType = CommandType.Text;
com1.CommandText = "select * from customer"
DataSet ds1 = new DataSet();
SqlDataAdapter adp1 = new SqlDataAdapter(com1);
adp1.Fill(ds1,"customer");
grd1.DataMember = "customer";
con1.Close();
}
}
}