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[英]Printing problem in C# windows app - Always prints to default printer
[英]Printing From WebBrowser control prints to wrong printer after setting default
我在VB.NET WinForms應用程序中有一個WebBrowser控件。 我可以通過代碼設置默認打印機並在不提示用戶的情況下進行打印。 但是,還有一個打印按鈕顯示PrintDialog。 如果先執行此操作,則將打印頁面。 然后,如果我稍后嘗試以編程方式打印(再次將默認打印機設置為其他打印機),即使我正在重置默認值並看到Windows中默認打印機的更改,它也將打印到PrintDialog框中選擇的最后一個打印機。
有任何想法嗎?
除非ShowPrintDialog首先選擇了打印機,否則它將正常工作。 一旦發生這種情況,無論我做什么,似乎總是使用該打印機。
For Each strPrinter In PrinterSettings.InstalledPrinters
If strPrinter.Contains("My Printer") Then
wScript.SetDefaultPrinter(strPrinter)
End If
Next
browser.Print()
我能夠獲得以下代碼,而不必打開/關閉單獨的表單。 自IE6以來,我一直在尋找這個...
另請參閱這兩篇文章。 以編程方式更改WinForms WebBrowser控件的目標打印機
// Add references for: COM: Microsoft Internet Controls; .NET: System.Management.dll
using System;
using System.Reflection;
using System.Threading;
using SHDocVw;
using System.Windows.Controls;
using System.Management;
namespace HTMLPrinting
{
public class HTMLPrinter
{
private bool documentLoaded;
private bool documentPrinted;
private string originalDefaultPrinterName;
private void ie_DocumentComplete(object pDisp, ref object URL)
{
documentLoaded = true;
}
private void ie_PrintTemplateTeardown(object pDisp)
{
documentPrinted = true;
}
public void Print(string htmlFilename, string printerName)
{
// Preserve default printer name
originalDefaultPrinterName = GetDefaultPrinterName();
// set new default printer
SetDefaultPrinter(printerName);
// print to printer
Print(htmlFilename);
}
public void Print(string htmlFilename)
{
documentLoaded = false;
documentPrinted = false;
InternetExplorer ie = new InternetExplorer();
ie.DocumentComplete += new DWebBrowserEvents2_DocumentCompleteEventHandler(ie_DocumentComplete);
ie.PrintTemplateTeardown += new DWebBrowserEvents2_PrintTemplateTeardownEventHandler(ie_PrintTemplateTeardown);
object missing = Missing.Value;
ie.Navigate(htmlFilename, ref missing, ref missing, ref missing, ref missing);
while (!documentLoaded && ie.QueryStatusWB(OLECMDID.OLECMDID_PRINT) != OLECMDF.OLECMDF_ENABLED)
Thread.Sleep(100);
ie.ExecWB(OLECMDID.OLECMDID_PRINT, OLECMDEXECOPT.OLECMDEXECOPT_DONTPROMPTUSER, ref missing, ref missing);
// Wait until the IE is done sending to the printer
while (!documentPrinted)
Thread.Sleep(100);
// Remove the event handlers
ie.DocumentComplete -= ie_DocumentComplete;
ie.PrintTemplateTeardown -= ie_PrintTemplateTeardown;
ie.Quit();
// reset to original default printer if needed
if (GetDefaultPrinterName() != originalDefaultPrinterName)
{
SetDefaultPrinter(originalDefaultPrinterName);
}
}
public static string GetDefaultPrinterName()
{
var query = new ObjectQuery("SELECT * FROM Win32_Printer");
var searcher = new ManagementObjectSearcher(query);
foreach (ManagementObject mo in searcher.Get())
{
if (((bool?)mo["Default"]) ?? false)
{
return mo["Name"] as string;
}
}
return null;
}
public static bool SetDefaultPrinter(string defaultPrinter)
{
using (ManagementObjectSearcher objectSearcher = new ManagementObjectSearcher("SELECT * FROM Win32_Printer"))
{
using (ManagementObjectCollection objectCollection = objectSearcher.Get())
{
foreach (ManagementObject mo in objectCollection)
{
if (string.Compare(mo["Name"].ToString(), defaultPrinter, true) == 0)
{
mo.InvokeMethod("SetDefaultPrinter", null, null);
return true;
}
}
}
}
return true;
}
}
}
我創建了一個沒有任何內容的表單。 啟動/關閉此表單的動作使它進入正確的打印機...我不知道為什么會起作用,但是必須調用某些函數來模擬在那里發生的任何行為。
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