Also talk about adding grid to database report in Delphi

The author designed a program. First, add a dbgrid on the form to display the data we want to print, here, DBGrid not only plays a role in displaying data, but also the user's adjustments to the DBGrid, such as changing the order of each field, the display width of each field, and so on, will be directly reflected in the print results, that is to say , we're actually just going to output the DBGrid content directly to the printer. The following program is compiled under Win 98+delphi 4 with the following code:

procedure Tform1.button2click (sender:tobject);


Const


leftblank=1; Define margin, unit cm


rightblank=1;


topblank=1;


bottomblank=1;


var


Pointx,pointy:integer;


Pointscale,printstep:integer;


s:string;


X,y:integer;


I:integer;


Begin//Get the resolution of the current printer


Pointx:=trunc (GetDeviceCaps (printer.handle,logpixelsx)/2.54);


Pointy:=trunc (GetDeviceCaps (printer.handle,logpixelsy)/2.54);


//To calculate the ratio from screen to printer based on printer and screen resolution


Pointscale:=trunc (GetDeviceCaps (printer.handle,logpixelsx)


/screen.pixelsperinch+0.5); Horizontal Print


Printer. Orientation:=polandscape;


//Print fonts and sizes


printer. canvas.font.name:=′ song body;


printer.canvas.font.size:=10;


//Depending on the size of the font to determine the height of each row


s:=′ Zhangzhou Interpol detachment;


Printstep:=printer.canvas.textheight (s) +16;


//Print start position


X:=pointx*leftblank;


Y:=pointy*topblank;


//datasource1 is the data source that DBGRID1 is connected to


if ((Datasource1.dataset). Active=true) and ((Datasource1.dataset). recordcount〉0) Then


begin


printer. Begindoc;


(Dataso E1. DataSet). A;


while not (Datasource1.dataset). Eof do


Begin//Print all columns in the DBGrid


for i:=0 to Dbgrid1.fieldcount-1 do


begin


//If the column you want to print is outside the print range, ignore the column


if (X+dbgrid1.columns.items[i]. Width*pointscale) 〈= (Printer.pagewidth-pointx*rightblank) then


Begin//Draw form line


//The first line of each page prints the header


Printer.Canvas.Rectangle (x,y,x+dbgrid1.columns.


Items[i]. WIDTH*POINTSCALE,Y+PRINTSTEP);


if Y=pointy*topblank then


Printer.Canvas.TextOut (x+8,y+8,dbgrid1.columns[i). Title.caption)


Else


Printer.Canvas.TextOut (x+8,y+8,dbgrid1.fields[i].asstring);


end; Calculate the horizontal axis of the next column


X:=x+dbgrid1.columns.items[i]. Width*pointscale;


end;


if not (Y=pointy*topblank) then


(Datasource1.dataset). Next;


X:=pointx*leftblank;


Y:=y+printstep; Change Page


if (y+printstep) (Printer.pageheight-pointy*bottomblank) then


begin


Printer.newpage;


Y:=pointy*topblank;


end;


end;


printer. EndDoc;


(Datasource1.dataset). A;


Application.messagebox (′,′ printing complete print ′,32);


end;


end;