c# – 如何从后台线程中使用FixedDocument？

概述当所有内容都在同一个线程上时,以下代码可以正常工作.但是,在后台线程上创建FixedDocument时,将PrintPreview移动到UI线程,我得到： “The calling thread cannot access this object because a different thread owns it.” 问题在于： writer.Write(fixeddocument.Docume 当所有内容都在同一个线程上时,以下代码可以正常工作.但是,在后台线程上创建Fixeddocument时,将PrintPrevIEw移动到UI线程,我得到：

“The calling thread cannot access this object because a different
thread owns it.”

问题在于：

writer.Write(fixeddocument.documentPaginator);

我无法获得dispatcher.invoke / begininvoke – 或其他任何东西来解决这个问题.

那么如何将另一个线程的Fixeddocument带到UI线程呢？

(请注意,Fixeddocument需要几分钟才能生成,因此必须在后台线程上创建.是的,我已经Google搜索了几个小时而没有找到任何解决方案.如果有,我错过了它).

我一直认为我必须将PrintPrevIEw保持在与Fixeddocument相同的线程中 – 我希望不会.

// Print PrevIEwpublic static voID PrintPrevIEw(Fixeddocument fixeddocument,CancellationToken ct){    // Was cancellation already requested?     if (ct.IsCancellationRequested)          ct.ThrowIfCancellationRequested();    MemoryStream ms = new MemoryStream();    using (Package p = Package.Open(ms,fileMode.Create,fileAccess.ReaDWrite))    {        Uri u = new Uri("pack://TemporaryPackageUri.xps");        PackageStore.AddPackage(u,p);        Xpsdocument doc = new Xpsdocument(p,Compressionoption.Maximum,u.absoluteUri);        XpsdocumentWriter writer = Xpsdocument.CreateXpsdocumentWriter(doc);        writer.Write(fixeddocument.documentPaginator);        FixeddocumentSequence fixeddocumentSequence = doc.GetFixeddocumentSequence();        var prevIEwWindow = new PrintPrevIEw(fixeddocumentSequence);        Action closeAction = () => prevIEwWindow.Close();        ct.Register(() =>              prevIEwWindow.dispatcher.Invoke(closeAction)         );       prevIEwWindow.ShowDialog();          PackageStore.RemovePackage(u);        doc.Close();    }}

解决方法 它显然是你方法中的静态修饰符.将其更改为实例方法可以促进dispatcher：

public partial class MainWindow : Window{    public MainWindow()    {        InitializeComponent();    }    // Print PrevIEw    public voID PrintPrevIEw(Fixeddocument fixeddocument,CancellationToken ct)    {        // Was cancellation already requested?         if (ct.IsCancellationRequested)            ct.ThrowIfCancellationRequested();        MemoryStream ms = new MemoryStream();        using (Package p = Package.Open(ms,fileAccess.ReaDWrite))        {            Uri u = new Uri("pack://TemporaryPackageUri.xps");            PackageStore.AddPackage(u,p);            Xpsdocument doc = new Xpsdocument(p,u.absoluteUri);            XpsdocumentWriter writer = Xpsdocument.CreateXpsdocumentWriter(doc);            //writer.Write(fixeddocument.documentPaginator);            dispatcher.Invoke(new Action<documentPaginator>(writer.Write),fixeddocument.documentPaginator);            FixeddocumentSequence fixeddocumentSequence = doc.GetFixeddocumentSequence();            var prevIEwWindow = new PrintPrevIEw(fixeddocumentSequence);            Action closeAction = () => prevIEwWindow.Close();            ct.Register(() =>                  prevIEwWindow.dispatcher.Invoke(closeAction)            );            prevIEwWindow.ShowDialog();            PackageStore.RemovePackage(u);            doc.Close();        }    }}

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