c# - Display brings up only one object of the list and list isn't adding properly -

so trying project in windows form determine number of vertices , assigns each vertex co-ordinate , outputs on form. reason isn't working take look?

mainform

    using system; using system.collections.generic; using system.componentmodel; using system.data; using system.drawing; using system.linq; using system.text; using system.threading.tasks; using system.windows.forms;  namespace assignment {     public partial class mainform : form     {         public mainform()         {             initializecomponent();         }          public list<vertex> vertexlist = new list<vertex>();          private void exit_click(object sender, eventargs e)         {             application.exit();         }          private void create_click(object sender, eventargs e)         {             int vertices = 0, edges = 0;             try             {                 vertices = (int)convert.toint32(txtvertices.text);                 edges = (int)convert.toint32(txtedges.text);                 if (vertices < 0)                     messagebox.show("vertices cannot less 0", "error", messageboxbuttons.ok, messageboxicon.error);                 else                     if (edges < 0 || edges > 1)                         messagebox.show("edges have 0..1", "error", messageboxbuttons.ok, messageboxicon.error);                     else                     {                         //messagebox.show("graph created", "info", messageboxbuttons.ok, messageboxicon.information);                          (int = 0; < vertices; i++)                         {                             vertex vertex = new vertex();                             vertex vertex1 = vertex.createvertex(vertices);                             vertexlist.add(vertex1);                                                      }                          vertexdisplay display = new vertexdisplay();                         display.displayvertices(vertexlist);                         display.show();                     }              }             catch(exception x)             {                 messagebox.show("vertices  or edges cannot left out", "error", messageboxbuttons.ok, messageboxicon.error);             }                    }     } } 

vertex class

    using system; using system.collections.generic; using system.linq; using system.text; using system.threading.tasks;  namespace assignment {     public class vertex     {         public int x;                 public int y;         public int z;         public int vertexid;          public int x         {             { return x; }             set { x = value; }         }                  public int y         {             { return y; }             set { y = value; }         }                  public int z         {             { return z; }             set { z = value; }         }                  public int vertexid         {             { return vertexid; }             set { vertexid = value; }         }          public vertex createvertex(int noofvertex)         {             random rnd = new random();              vertex vertex = new vertex(x, y, z, vertexid);             mainform mainform = new mainform();             vertex.x = rnd.next(0, 100);             vertex.y = rnd.next(0, 100);             vertex.z = rnd.next(0, 100);              vertex.vertexid = rnd.next(0, noofvertex);              return(vertex);         }         public vertex()         {          }         public vertex(int x, int y, int z, int id)         {             this.x = x;             this.y = y;             this.z = z;             this.vertexid = id;         }     }  } 

display from

using system; using system.collections.generic; using system.componentmodel; using system.data; using system.drawing; using system.linq; using system.text; using system.threading.tasks; using system.windows.forms;  namespace assignment {     public partial class vertexdisplay : form     {         public vertexdisplay()         {             initializecomponent();             mainform mainform = new mainform();             displayvertices(mainform.vertexlist);         }         public void displayvertices(list<vertex>vertexlist)         {             int x, y, z, id;             foreach(vertex vertexdetails in vertexlist)             {                 x = vertexdetails.x;                 y = vertexdetails.y;                 z = vertexdetails.z;                 id = vertexdetails.vertexid;                  txtvertexdisplay.text = string.join(environment.newline, " id: " + id + " x: " + x + " y: " + y + " z: " + z);             }         }     } } 

you setting txtvertexdisplay.text property inside foreach loop setting each time loop iterate. not concatenation it's beeing set something. if want concatenate output - use temporary string property , += operator. see below:

 public void displayvertices(list<vertex>vertexlist)     {         string displaytext = string.empty;         int x, y, z, id;         foreach(vertex vertexdetails in vertexlist)         {             x = vertexdetails.x;             y = vertexdetails.y;             z = vertexdetails.z;             id = vertexdetails.vertexid;              displaytext += string.join(environment.newline, " id: " + id + " x: " + x + " y: " + y + " z: " + z);         }         txtvertexdisplay.text = displaytext;     }