Shulou(Shulou.com)06/02 Report--

Delphi how to call driver printing, I believe that many inexperienced people do not know what to do, so this paper summarizes the causes of the problem and solutions, through this article I hope you can solve this problem.

Introduction to the TPrinter class

The interface of the Windows printer is encapsulated in the TPrinter class.

Class relation TObject

Use the TPrinter object to perform any print operation in your application. You can get a TPrinter object in the Printers unit by calling the Printer function. To determine how to display the printed image of the form, you can use the PrintScale property of the Tform component.

You can print after a text variable or a printer canvas is ready. Printing continues until the EndDoe procedure is called. The topics displayed on the PrintManager (or web front page) are determined by the Title property. If you want to start printing, you can call the BeginDoc method. To finish a successful print, you need to call the EndDoc procedure. If there is a problem and you need to interrupt printing, you can call the Abort method.

Attribute list

Aborted interrupt printing

Indicates whether the user currently interrupts printing, thus calling the method

_ _ property bool Aborted = {read = FAborted,nodefalt}

If the property Aborted is true, the printing work has been interrupted. If it is false, it means that the user has not interrupted the printing process.

The surface of the currently printed page of Canvas

Represents the surface of the currently printed page.

_ _ property Graphics:: TCanvas * Canvas = {read = GetCanvas}

The property Canvas represents the printed surface of a page. Use the Brush,Font and Pen properties of the Canvas object to determine how the page is drawn and displayed. Some printers do not support images, so calling the Draw,StretchDraw or CopyRect method on these printers will fail.

Capabilities indicates the current settings of a print device driver

Indicates the current settings for a print device driver.

_ _ property TPrinterCajpabilities Caoabukutues = {read = FCapabities, nodefault}

The property Capabilities contains printer compatibility, which specifies the direction of printing, the number of pages, and whether to proofread.

Copies specifies the number of copies to print

Specifies the number of copies to print.

_ _ property int Copies = {read = GetNumCopies, write = SetNumCopies, nodefault}

The number of copies printed is specified in the property Copies.

Fonts lists the fonts supported by the current printer

Lists the fonts supported by the current printer.

_ _ property Classes;; TStrings * Fonts = {read = GetFonts}

Use the Fonts property to get a list of fonts supported by the current printer. TrueType fonts are always included in the list, even if they are not included in the printer, because Windows Graphies Device Interface (GDI) can accurately draw the font when used by the printer.

Handle provides the ability to access printer object handles

Provides the ability to access printer object handles.

_ _ property HdC Handle = {read = GetHandle, node fault}

Use the Handle property to get access to the printer object handle.

Orientation determines the direction in which the print works on the page

Determine the direction in which the print works on the page, vertical or horizontal.

_ _ property TpinterOrientation Orientation = {read = GetPrientatiion, write = SetOrienatiion, nodefault}

Use the Orientation property to determine the direction in which the printer prints. The Onienation property value can only be of type TPrinterOrientation. The possible values of the property are listed in the following table:

TPrinter::PageHeight

Indicates the pixel height of the currently printed page.

_ _ property int PageHeight = {read = GetPageHeight, nodefault}

The pixel height of the current printed page can be found in the property PageHeight.

PageHeight indicates the pixel height of the currently printed page

Indicates the pixel height of the currently printed page.

PateNurnber indicates the current printed page

Indicates the currently printed page.

_ _ property int PageNumber = {read = FPageNumber, nodefault}

You can get the currently printed page number in the property PageNumber. The property PageNumber is incremented by 1 after the NewPage method is called. When you enter a carriage return at the end of the page and write a text variable, the property PageNumber is also incremented by 1.

PageWidth indicates the pixel width of the current printed page

Indicates the pixel width of the currently printed page.

_ _ property int PageWidth = {read = GetPageWidth, modefault}; the pixel width of the current printed page can be found in the property PsheWifyh.

Printerlndex lists the current printer in the Printers property

Specifies that the printer listed in the Printers property is the current printer.

_ _ property int Printerlndex = {read = GetPrinterlndex, write = SetPrinterlndex, nodefault}

The property Printerlndex specifies the current printer. If you change the value of this property, the EndDoc method will be called automatically. If you want to choose the default printer, you can set the property Printerlndex to-1. The installed printers are listed in the Printers property. The list of fonts currently supported by the printer is in the Fonts property.

Printers lists all printers installed in Windows

List all printers installed in Windows.

_ _ property Classes:: TStrings * Printers = {read = GePrinters}; all printers installed in Windows are listed in the Printers property. The property Printerlndex specifies the currently selected printer. The list of fonts currently supported by the printer is in the Fonts property.

Printing indicates that printing is in progress

Indicates that printing is in progress.

_ _ property bool Printing = {read = FPrinting, nodefault}

Use the Printing property to determine whether a print job is in progress. If the BeginDoc method is called in the application and the Printing property is set to true before calling the EndDoc method (or the Abort method).

The text displayed by Title on the front page of the main network in Ptint Manager

Determines the text to be displayed in Print Manager and in the web front page.

_ _ property Systen:: AndiString Title = {read = FTitle, wrete = FTitle}

The property Title is used by Windows in Print Manager and also serves as the front page of the network.

Method list

~ TPrinter deletes a printer instance

_ _ fastcall virtual ~ TPrinter (void)

Generally, the ~ TPrinter method is not called directly. Printer objects are automatically created and deleted. When the ~ TPrinter method is called, it checks to see if the printing work is finished. If it's over, release the resources. Such as handles, fonts, canvases, etc., and finally turn off the printer and call the inherited destructor.

Abort interrupt printing

Void _ fastcall Abort (void)

Interrupt printing and discard unprinted data.

Use the Abort method to interrupt printing before the printing job is complete, otherwise the EndDoc method will be used. After calling the Abort method, the device is set to the next print job.

BeginDoc sends a print job to the printer

_ void _ _ fastcall BeginDoc (void)

Send a print job to the printer.

Call BeginDoc to initialize a print job. If the printing work is successfully fed, the application will call the EndDoc method to end the printing. Printing actually starts only after the EndDoc method is called.

EndDoc ends the current printing job and closes the text file variable

Void _ fastcall EndDoc (void)

Ends the current printing job and closes the file variable.

Calling the EndDoc method ends printing (and closes the currently open style). Printing starts after the end of the EndDoc method call. After calling the EndDoc method in the application, the printer starts printing. The EndDoc method is called after a print job is successfully sent to the printer. If the printing job is not successful, the Abort method is called.

GrtPrinter retrieves the current printer

Void _ fastcall GetPrinter (char* ADevice,char* ADriver,char* APort,int& ADeviceMode)

Retrieve the current printer.

You do not need to call the GetPrinter method directly. This can be obtained by accessing the printer in the Printers properties array. For more information, see the CreateDC function in Win32Developer's Reference (WIN32::HLP).

NewPage starts a new page

Void _ fastcall NewPage (void)

Start a new page and add 1 to the value of the PageNumber property.

Using the NewPage method forces printing to continue on the new page of the printer.

The NewPage method adds 1 to the value of the PageNumber property. At the same time, the Pen property of the Canvas object will be set to (0mem0).

SetPrinter specifies a printer as the current printer

Void _ fastcall SetPrinter (char* ADevice,char* ADriver,char* APort,int ADeviceMode)

Specify a printer as the current printer.

The SetPrinter method is not called directly. You can set this by accessing the printer in the Printers properties array. For more information, see the CreateDC function in Win32Developer's Reference (WIN32.HLP).

TPrinter creates a printer

_ _ fastcall TPrinter (void)

Create a printer.

The TPrinter method cannot be called directly. The TPrinter method will be called automatically by the Printer function. Method allocates memory for the printer and calls the inherited constructor. Then set the correct drive, device, and port.

TPrinter:

Code demonstration

/ / you must first get the actual size of the printer:

Var

Pointx,pointy:integer

Pointx:=getdevicecaps (printer.handle,logpixelsx)

Pointy:=getdevicecaps (printer.handle,logpixelsy)

Printer.canvas.TextOut (X-ray pointx.Y-point point text)

/ / Note that Printer needs to add a Printers reference.

If printdialog1.Execute then

Begin

Printer.BeginDoc

Printer.Title: = 'memo content'

Printer.Canvas.TextOut (100pi 100pi 'print content')

Printer.EndDoc

End

/ / print string function

Procedure PosPrintStr (SizeType,ColorType:integer; str:string)

Var ls:TStrings

Begin

/ / print test parameter ticket output to file XSysPrint.Log

If PosCfg.blPrnText then

Begin

WritePrintTxt (str)

{ls: = TStringList.Create

Ls.Clear

Try

Ls.Add (str)

TEXT_PrintString (PosCfg.sPrinterPort,0,0,ls)

Finally

Ls.Free

End

DelayMSec (PosCfg.nPrnDelay);}

Exit

End

If PosCfg.sPrinterType='TM300K' then

Begin

TM300K_PrintStr (sPrinterPortID,SizeType,ColorType,str)

DelayMSec (PosCfg.nPrnDelay); / / print delay

End

Else if PosCfg.sPrinterType='TM200D' then

Begin

TM200D_PrintStr (sPrinterPortID,SizeType,ColorType,str)

DelayMSec (PosCfg.nPrnDelay); / / print delay

End

Else if PosCfg.sPrinterType='TEC200D' then

Begin

LPTDOT_PrintStr (sPrinterPortID,1,str); / / parallel port printing

DelayMSec (PosCfg.nPrnDelay); / / print delay

End

Else if PosCfg.sPrinterType='TM210D' then

Begin

TM210D_PrintString (sPrinterPortID,SizeType,ColorType,str); / / Universal parallel port printing

DelayMSec (PosCfg.nPrnDelay); / / print delay

End

Else if PosCfg.sPrinterType='TEXTFILE' then / / Universal text printing

Begin

TEXT_PrintString (PosCfg.sPrinterPort,SizeType,ColorType,str)

DelayMSec (PosCfg.nPrnDelay); / / print delay

End

Else if PosCfg.sPrinterType='OTHER' then

Begin

Other_PrintString (sPrinterPortID,SizeType,ColorType,str)

DelayMSec (PosCfg.nPrnDelay); / / print delay

End

Else begin

TM200D_PrintStr (sPrinterPortID,SizeType,ColorType,str)

DelayMSec (PosCfg.nPrnDelay); / / print delay

End

End

/ / simulate printing test text

Procedure WritePrintTxt (sMessage: String)

Const PRINT_FILE='XSysPrint.Log'

Var

Fname, fname0: String

Fp: TextFile

Begin

/ / create a log file

Fname:=DirConcat (UGetAppPath,PRINT_FILE)

If not FileExists (fname) then

Begin

AssignFile (fp,fname)

Rewrite (fp)

Writeln (fp,' Analog print')

Flush (fp)

CloseFile (fp)

End

/ / record log information

AssignFile (fp,fname)

Try

Append (fp)

Writeln (fp,sMessage)

Flush (fp)

Finally

CloseFile (fp)

End

End

After reading the above, have you mastered how to call the driver printing method in Delphi? If you want to learn more skills or want to know more about it, you are welcome to follow the industry information channel, thank you for reading!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.