gdi+ 打印的问题，尺寸不对。

[ljn2]

我的打印机在A4上是(像素：4800,6800，毫米210,288),
不知gdi+使用的是哪种单位，画了个0,0,100,100的框，打印到A4纸上一看，
如果说是像素，那么明显大于了100,100的范围，如果说是1/10毫米，又明显太小.
那位打过，给个提示啊

[ljn2]

up

[ljn2]

up

[abrams]

把你代码贴出来

[ljn2]

#include "stdafx.h"
#include <windows.h>
#include <gdiplus.h>
#include <stdio.h>
using namespace Gdiplus;

INT main()
{
// Initialize GDI+.
GdiplusStartupInput gdiplusStartupInput;
ULONG_PTR gdiplusToken;
GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);

DOCINFO docInfo;
ZeroMemory(&docInfo, sizeof(DOCINFO));
docInfo.cbSize = sizeof(DOCINFO);
docInfo.lpszDocName = "GdiplusPrint";

// Create a PRINTDLG structure, and initialize the appropriate fields.
PRINTDLG printDlg;
ZeroMemory(&printDlg, sizeof(PRINTDLG));
printDlg.lStructSize = sizeof(PRINTDLG);
printDlg.Flags = PD_RETURNDC;

// Display a print dialog box.
if(!PrintDlg(&printDlg))
{
printf("Failure\n");
}
else
{
// Now that PrintDlg has returned, a device context handle
// for the chosen printer is in printDlg->hDC.

StartDoc(printDlg.hDC, &docInfo);
StartPage(printDlg.hDC);
Graphics* graphics = new Graphics(printDlg.hDC);
Pen* pen = new Pen(Color(255, 0, 0, 0));
graphics->DrawRectangle(pen, 200, 500, 200, 150);
graphics->DrawEllipse(pen, 200, 500, 200, 150);
graphics->DrawLine(pen, 200, 500, 400, 650);
delete pen;
delete graphics;
EndPage(printDlg.hDC);
EndDoc(printDlg.hDC);
}

if(printDlg.hDevMode)
GlobalFree(printDlg.hDevMode);
if(printDlg.hDevNames)
GlobalFree(printDlg.hDevNames);
if(printDlg.hDC)
DeleteDC(printDlg.hDC);

GdiplusShutdown(gdiplusToken);
return 0;

}

[geniusage]

GDI+用World Transformation（世界坐标），page Transformation 和device Transformation 三种坐标。你画的是用像素，画出来的大小，根据你
的设备的dpi,就是//REAL dpiX = graphics.GetDpiX();
//REAL dpiY = graphics.GetDpiY();
你可以算出大小来，如果是96,就是37.795像素/厘米，

那377.95像素就是10厘米

[zhangcrony]

楼主被封杀，大家不要回了

[geniusage]

就是说你传的(200, 500) ,(200, 150)是世界坐标，gdi+做了两次转换，
world->page->device

[geniusage]

为什么被封杀呢

[smallbull]

关注

[ljn2]

谢谢geniusage(),我再试试.

to zhangcrony,我还健在.

[mynameisno1]

什么叫被封杀？

映射模式设了吗
SetMapMode()

[ljn2]

封杀并不是问题的关键，大家不用老是盯着不放

SetMapMode是gdi函数，gdi+里不管用。估计得用SetPageUnit

[Boll]

The Unit enumeration specifies the unit of measure for a given data type.

Syntax

typedef enum {
UnitWorld = 0,
UnitDisplay = 1,//1/96英寸
UnitPixel = 2, //1像素
UnitPoint = 3,//1/72英寸
UnitInch = 4,
UnitDocument = 5,//1/300英寸
UnitMillimeter = 6//1mm
} Unit;

Constants

UnitWorld
Specifies world coordinates, a nonphysical unit.

UnitDisplay
Specifies display units. For example, if the display device is a monitor, then the unit is 1 pixel.

UnitPixel
Specifies that a unit is 1 pixel.

UnitPoint
Specifies that a unit is 1 point or 1/72 inch.

UnitInch
Specifies that a unit is 1 inch.

UnitDocument
Specifies that a unit is 1/300 inch.

UnitMillimeter
Specifies that a unit is 1 millimeter.

是啊，你用SetPageUnit设置坐标计量单位是对的

[ljn2]

OK 搞定了谢谢大家