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在c#中使用printdialog可以很方便的实现程序的打印功能。
其步骤如下：
创建一个printdialog的实例。如下：
system.windows.forms.printdialog printdialog1=new printdialog ();
创建一个printdocument的实例.如下：
system.drawing.printing.printdocument doctoprint =
new system.drawing.printing.printdocument();
设置打印机开始打印的事件处理函数.函数原形如下：
void doctoprint_printpage(object sender,
system.drawing.printing.printpageeventargs e)
将事件处理函数添加到printdocument的printpage事件中。
doctoprint.printpage+=new printpageeventhandler(doctoprint_printpage);
设置printdocument的相关属性，如：
printdialog1.allowsomepages = true;printdialog1.showhelp = true;
把printdialog的document属性设为上面配置好的printdocument的实例：
printdialog1.document = doctoprint;
调用printdialog的showdialog函数显示打印对话框：
dialogresult result = printdialog1.showdialog();
根据用户的选择，开始打印：
if (result==dialogresult.ok)
{
doctoprint.print();
}
例子如下：
使用时先创建printservice类的实例，然后调用void startprint(stream streamtoprint,string streamtype)函数开始打印。其中streamtoprint是要打印的内容（字节流），streamtype是流的类型（txt表示普通文本，image表示图像）；
——————————————————————————–
using system;
using system.drawing.printing;
using system.windows.forms;
using system.io;
namespace edimagesystem
{
/// <summary>
/// printservice 的摘要说明。
/// </summary>
public class printservice
{
public printservice()
{
//
// todo: 在此处添加构造函数逻辑
//
this.doctoprint.printpage+=new printpageeventhandler(doctoprint_printpage);
}//将事件处理函数添加到printdocument的printpage中
// declare the printdocument object.
private system.drawing.printing.printdocument doctoprint =
new system.drawing.printing.printdocument();//创建一个printdocument的实例
private system.io.stream streamtoprint;
string streamtype;
// this method will set properties on the printdialog object and
// then display the dialog.
public void startprint(stream streamtoprint,string streamtype)
{
this.streamtoprint=streamtoprint;
this.streamtype=streamtype;
// allow the user to choose the page range he or she would
// like to print.
system.windows.forms.printdialog printdialog1=new printdialog ();//创建一个printdialog的实例。
printdialog1.allowsomepages = true;
// show the help button.
printdialog1.showhelp = true;
// set the document property to the printdocument for
// which the printpage event has been handled. to display the
// dialog, either this property or the printersettings property
// must be set
printdialog1.document = doctoprint;//把printdialog的document属性设为上面配置好的printdocument的实例
dialogresult result = printdialog1.showdialog();//调用printdialog的showdialog函数显示打印对话框
// if the result is ok then print the document.
if (result==dialogresult.ok)
{
doctoprint.print();//开始打印
}
}
// the printdialog will print the document
// by handling the document’s printpage event.
private void doctoprint_printpage(object sender,
system.drawing.printing.printpageeventargs e)//设置打印机开始打印的事件处理函数
{
// insert code to render the page here.
// this code will be called when the control is drawn.
// the following code will render a simple
// message on the printed document
switch(this.streamtype)
{
case "txt":
string text = null;
system.drawing.font printfont = new system.drawing.font
("arial", 35, system.drawing.fontstyle.regular);
// draw the content.
system.io.streamreader streamreader=new streamreader(this.streamtoprint);
text=streamreader.readtoend();
e.graphics.drawstring(text,printfont,system.drawing.brushes.black,e.marginbounds.x,e.marginbounds.y);
break;
case "image":
system.drawing.image image=system.drawing.image.fromstream(this.streamtoprint);
int x=e.marginbounds.x;
int y=e.marginbounds.y;
int width=image.width;
int height=image.height;
if((width/e.marginbounds.width)>(height/e.marginbounds.height))
{
width=e.marginbounds.width;
height=image.height*e.marginbounds.width/image.width;
}
else
{
height=e.marginbounds.height;
width=image.width*e.marginbounds.height/image.height;
}
system.drawing.rectangle destrect=new system.drawing.rectangle(x,y,width,height);
e.graphics.drawimage(image,destrect,0,0,image.width,image.height,system.drawing.graphicsunit.pixel);
break;
default:
break;
}
}
}
}
