printing - C# PrintDocument only prints an empty page -

i´m trying print datagridview , printer prints white page. know datagridview not empty because appear on form. tried doing printpreviewdialog shows white page. code , dont know wrong.

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.drawing.printing;  namespace prueba {     public partial class form4 : form     {         public form4()         {             initializecomponent();         }         private void imprimirbtn_click(object sender, eventargs e)         {                printdocument1.print();         }         private void printdocument1_printpage(object sender, system.drawing.printing.printpageeventargs e)         {             font printfont = new font("arial", 10);             float topmargin = e.marginbounds.top;             float ypos = 0;             float linesperpage = 0;             int count = 0;             string texto = "";             int = -1;             datagridviewrow row;              linesperpage = e.marginbounds.height / printfont.getheight(e.graphics);              while (count < linesperpage && < this.datagridview1.rows.count)             {                 row = datagridview1.rows[i];                 texto = "";                  foreach (datagridviewcell celda in row.cells)                 {                     texto += "\t" + celda.value.tostring();                 }                 ypos = topmargin + (count * printfont.getheight(e.graphics));                 e.graphics.drawstring(texto, printfont, brushes.black, 10, ypos);                  count++;                 i++;                 if (i < this.datagridview1.rows.count)                     e.hasmorepages = true;                 else                 {                     = 0;                 }             }     } } 

you forgot add eventhandler printing process.

private void imprimirbtn_click(object sender, eventargs e)     {            printdocument1.printpage += new printpageeventhandler(printdocument1_printpage);         printdocument1.print();     }