extern external methods use C # simple example

External methods use C # simple example

1. Add reference using System.Runtime.InteropServices;

2. Declaration and implementation of the connection [DllImport ("kernel32", SetLastError = True)]

3. Declare the external method public static extern int GetCurrentDirectory (int A, StringBuilder b);

4, the External method operation GetCurrentDirectory (pathstring);

Using system;using system.collections.generic;using system.componentmodel;using system.data;using System.Drawing; Using system.linq;using system.text;using system.windows.forms;using system.runtime.interopservices;// Reference external namespace extern{public    partial class Dllimportform:form    {public        dllimportform ()        {            InitializeComponent ();        }        [DllImport ("kernel32", SetLastError = True)]//declaration and implementation of the connection public        static extern int getcurrentdirectory (int A, StringBuilder b);//external method               private void Btndisplay_click (object sender, EventArgs e)        {            StringBuilder Pathstring=new StringBuilder ();//return path            getcurrentdirectory (pathstring);           THIS.LISTBOX1.ITEMS.ADD (pathstring);}}}    

extern external methods use C # simple example