重置delphi Printer对象

http://www.efg2.com/Lab/Library/UseNet/1999/0714b.txt

 

From: "Nick Ryan" <[email protected]>

Subject: Re: D1 printing problem: incorrect font sizes

Date: 14 Jul 1999 00:00:00 GMT

Message-ID: <[email protected]>

References: <[email protected]>

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Daniel Berg (Berg Soft) <[email protected]> wrote in message

news:[email protected]...

> Hi there,

>

> I've got the following the following problem using D1 (on D2 and later

> the problem does not occur)

>

>

> I can select different printers with different resolutions from the

> printdialog.我可以从打印机对话框里 选相应不同分辨率的不同打印机。

> Printing to any printer works fine when the prog just started (i.e:

> Printing to Printer1, then shutdown prog, run again, then print to

> Printer 2 works perfect). 当程序刚启动时，打印到任何一个打印机都是正常的。比如打印到 打印机1，然后关闭程序。 再次运行，然后打印 到 打印机2，一起正常。

>

> Printing to a second printer AFTER printing to a first printer scales

> all fonts by

>

> Resolution(Printer1)/resolution(Printer2);
打印到第一个打印机后，（不关闭程序）直接再打印到第二个打印机时，缩放了所有的字体 以
第一个打印机 分辨率 / 第二个打印机分辨率 的比例。
>

> I have already tried the following without success:

>

> -   Creation of the form that uses the printers unit at runtime AFTER

> printdialog.execute to create a new printer instance everytime

>

> -   I have checked printers resolution with GetDeviceCaps: printer

> change is  recognized correctly.

>

> Does anyone has an idea of whats wrong?



It's some weird bug in Delphi's TPrinter that causes information to be

retained from a previous print session. (It affects the line thickness of

printing using D3).

这是打印机对象中的一些奇怪BUG。导致信息 从前一次打印会话中 保留。



The following code forces a complete refresh of the Printer object in D3 -

it *should* work in D1 as well...



procedure ResetTPrinter;

var

  APrinter:TPrinter;

begin

    if (not Printer.Printing) then begin

      APrinter := SetPrinter(NIL);

      if (APrinter <> NIL) then APrinter.Free;

    end; {if}

end;
//我看新版的VCL源代码里直接 一行代码 就行了 SetPrinter(nil).Free;



Nick