使用backgroundworker更新progressbar + clipboard.getimage（） - WPF C＃ [英] Update progressbar + clipboard.getimage() with backgroundworker - WPF C#

问题描述

你好



我的程序应该将文件夹中的某些Excel文件作为图像（SVG格式）导出到另一个文件夹中。这可以通过方法CopyAndSaveTo和ExportRangeAsImage来完成它们完成它们的工作。

在MainWindow上我有一个按钮，当它被点击时执行这两个功能。我希望通知点击此按钮的用户（进度条）这个过程有多远（复制+导出）。

我试图用BackgroundWorker实现它，只有当我发表评论时它才有效下面的代码（在方法ExportRangeAsImage中）：

 Bitmap image = new Bitmap（System.Windows.Forms.Clipboard.GetImage（））; 
 image.Save（ImagePath + Path.GetFileNameWithoutExtension（file）+。svg）; 

否则我得到了以下错误消息（

从德语翻译）：



在System.NullReferenceException中类型为System.Drawing.dll的异常已发生，但未在用户代码中处理。



附加信息：对象引用未设置为对象实例。



如果处理程序可用于此异常，程序可以继续安全运行。





以下是整个代码：

  private   void  UpdateDataOfLine1（ object  sender，ExecutedRoutedEventArgs e）
 {
  string  [] files = Directory.GetFiles（RootPath）; 
 
 BackgroundWorker worker =  new  BackgroundWorker（）; 
 worker.WorkerReportsProgress =  true ; 
 worker.DoWork + = worker_DoWork; 
 worker.ProgressChanged + = worker_ProgressChanged; 
 worker.RunWorkerAsync（）; 
} 
 
 
 
  void  worker_DoWork（ object  sender，DoWorkEventArgs e）
 {
  string  [] files = Directory.GetFiles（RootPath）; 
 
  for （ int  i =  0 ; i <  files.Length; i ++）
 {
  if （files [i] .Contains（  $）|| files [i] .Contains（ 〜）|| files [i] .Contains（  Thumb））
 {
  continue ; 
} 
 
 File.Copy（files [i]，DestPath + Path.GetFileName（files [i]）， true ） ; 
 
  string  newFile = DestPath + Path.GetFileName（files [i]）; 
 
 ExPortRangeAsImage（newFile）; 
 
（发件人 as  BackgroundWorker）.ReportProgress（i）; 
 Thread.Sleep（ 100 ）; 
} 
} 
 
 
 
  void  worker_ProgressChanged（对象发​​件人，ProgressChangedEventArgs e）
 {
 Status.Value = e.ProgressPercentage; 
} 
 
 
  public   void  ExPortRangeAsImage（< span class =code-keyword> string  file）
 {
  var  ExcelApp =  new  Microsoft.Office.Interop.Excel.Application（）; 
 
 尝试 
 {
 如果（文件。包含（  BeispielDatei））
 {
工作簿wb = ExcelApp.Workbooks 。打开文件）; 
工作表ws =（工作表）wb.Sheets [ 1 ]; 
范围= ws.Range [  A1：U35]; 
 range.CopyPicture（XlPictureAppearance.xlScreen，XlCopyPictureFormat.xlBitmap）; 
 wb.Close（SaveChanges： false ）; 
 Marshal.ReleaseComObject（wb）; 
} 
 
  else  
 {
工作簿wb = ExcelApp.Workbooks.Open（文件）; 
工作表ws =（工作表）wb.Sheets [ 1 ]; 
范围= ws.Range [  A1：U35]; 
 range.CopyPicture（XlPictureAppearance.xlScreen，XlCopyPictureFormat.xlBitmap）; 
 wb.Close（SaveChanges： false ）; 
 Marshal.ReleaseComObject（wb）; 
} 
} 
 
 最后 
 {
 Bitmap image =  new 位图（System.Windows.Forms.Clipboard.GetImage（））; 
 image.Save（ImagePath + Path.GetFileNameWithoutExtension（file）+  。svg） ; 
 
 Marshal.ReleaseComObject（ExcelApp）; 
} 
} 

我的尝试：

  private   void  UpdateDataOfLine1 （ object  sender，ExecutedRoutedEventArgs e）
 {
  string  [] files = Directory .GetFiles（ROOTPATH）; 
 
 BackgroundWorker worker =  new  BackgroundWorker（）; 
 worker.WorkerReportsProgress =  true ; 
 worker.DoWork + = worker_DoWork; 
 worker.ProgressChanged + = worker_ProgressChanged; 
 worker.RunWorkerAsync（）; 
} 
 
 
 
  void  worker_DoWork（ object  sender，DoWorkEventArgs e）
 {
  string  [] files = Directory.GetFiles（RootPath）; 
 
  for （ int  i =  0 ; i <  files.Length; i ++）
 {
  if （files [i] .Contains（  $）|| files [i] .Contains（ 〜）|| files [i] .Contains（  Thumb））
 {
  continue ; 
} 
 
 File.Copy（files [i]，DestPath + Path.GetFileName（files [i]）， true ） ; 
 
  string  newFile = DestPath + Path.GetFileName（files [i]）; 
 
 ExPortRangeAsImage（newFile）; 
 
（发件人 as  BackgroundWorker）.ReportProgress（i）; 
 Thread.Sleep（ 100 ）; 
} 
} 
 
 
 
  void  worker_ProgressChanged（对象发​​件人，ProgressChangedEventArgs e）
 {
 Status.Value = e.ProgressPercentage; 
} 
 
 
  public   void  ExPortRangeAsImage（< span class =code-keyword> string  file）
 {
  var  ExcelApp =  new  Microsoft.Office.Interop.Excel.Application（）; 
 
 尝试 
 {
 如果（文件。包含（  BeispielDatei））
 {
工作簿wb = ExcelApp.Workbooks 。打开文件）; 
工作表ws =（工作表）wb.Sheets [ 1 ]; 
范围= ws.Range [  A1：U35]; 
 range.CopyPicture（XlPictureAppearance.xlScreen，XlCopyPictureFormat.xlBitmap）; 
 wb.Close（SaveChanges： false ）; 
 Marshal.ReleaseComObject（wb）; 
} 
 
  else  
 {
工作簿wb = ExcelApp.Workbooks.Open（文件）; 
工作表ws =（工作表）wb.Sheets [ 1 ]; 
范围= ws.Range [  A1：U35]; 
 range.CopyPicture（XlPictureAppearance.xlScreen，XlCopyPictureFormat.xlBitmap）; 
 wb.Close（SaveChanges： false ）; 
 Marshal.ReleaseComObject（wb）; 
} 
} 
 
 最后 
 {
 Bitmap image =  new 位图（System.Windows.Forms.Clipboard.GetImage（））; 
 image.Save（ImagePath + Path.GetFileNameWithoutExtension（file）+  。svg） ; 
 
 Marshal.ReleaseComObject（ExcelApp）; 
} 
} 

你能告诉我我在做什么吗错误或我如何实现它？

除了BackgroundWorker还有其他方法吗？



提前感谢您的帮助！

解决方案

）|| files [i] .Contains（ 〜）|| files [i] .Contains（ Thumb））
{
continue ;
}

File.Copy（files [i]， DestPath + Path.GetFileName（files [i]）， true ）;

string newFile = DestPath + Path.GetFileName（files [i]）;

ExPortRangeAsImage（newFile）;

（sender as Backgroun dWorker）.ReportProgress（ⅰ）;
Thread.Sleep（ 100 ）;
}
}



void worker_ProgressChanged（对象发​​件人，ProgressChangedEventArgs e）
{
Status.Value = e.ProgressPercentage;
}


public void ExPortRangeAsImage（< span class =code-keyword> string file）
{
var ExcelApp = new Microsoft.Office.Interop.Excel.Application（）;

尝试
{
如果（文件。包含（ BeispielDatei））
{
工作簿wb = ExcelApp.Workbooks 。打开文件）;
工作表ws =（工作表）wb.Sheets [ 1 ];
范围= ws.Range [ A1：U35];
range.CopyPicture（XlPictureAppearance.xlScreen，XlCopyPictureFormat.xlBitmap）;
wb.Close（SaveChanges： false ）;
Marshal.ReleaseComObject（wb）;
}

else
{
工作簿wb = ExcelApp.Workbooks.Open（文件）;
工作表ws =（工作表）wb.Sheets [ 1 ];
范围= ws.Range [ A1：U35];
range.CopyPicture（XlPictureAppearance.xlScreen，XlCopyPictureFormat.xlBitmap）;
wb.Close（SaveChanges： false ）;
Marshal.ReleaseComObject（wb）;
}
}

最后
{
Bitmap image = new 位图（System.Windows.Forms.Clipboard.GetImage（））;
image.Save（ImagePath + Path.GetFileNameWithoutExtension（file）+ 。svg） ;

Marshal.ReleaseComObject（ExcelApp）;
}
}

我的尝试：

  private   void  UpdateDataOfLine1 （ object  sender，ExecutedRoutedEventArgs e）
 {
  string  [] files = Directory .GetFiles（ROOTPATH）; 
 
 BackgroundWorker worker =  new  BackgroundWorker（）; 
 worker.WorkerReportsProgress =  true ; 
 worker.DoWork + = worker_DoWork; 
 worker.ProgressChanged + = worker_ProgressChanged; 
 worker.RunWorkerAsync（）; 
} 
 
 
 
  void  worker_DoWork（ object  sender，DoWorkEventArgs e）
 {
  string  [] files = Directory.GetFiles（RootPath）; 
 
  for （ int  i =  0 ; i <  files.Length; i ++）
 {
  if （files [i] .Contains（  

）|| files [i] .Contains（ 〜）|| files [i ] .Contains（ Thumb））
{
继续;
}

File.Copy（files [i]，DestPath + Path.GetFileName（files [i]）， true ） ;

string newFile = DestPath + Path.GetFileName（files [i]）;

ExPortRangeAsImage（newFile）;

（发件人 as BackgroundWorker）.ReportProgress（i）;
Thread.Sleep（ 100 ）;
}
}



void worker_ProgressChanged（对象发​​件人，ProgressChangedEventArgs e）
{
Status.Value = e.ProgressPercentage;
}


public void ExPortRangeAsImage（< span class =code-keyword> string file）
{
var ExcelApp = new Microsoft.Office.Interop.Excel.Application（）;

尝试
{
如果（文件。包含（ BeispielDatei））
{
工作簿wb = ExcelApp.Workbooks 。打开文件）;
工作表ws =（工作表）wb.Sheets [ 1 ];
范围= ws.Range [ A1：U35];
range.CopyPicture（XlPictureAppearance.xlScreen，XlCopyPictureFormat.xlBitmap）;
wb.Close（SaveChanges： false ）;
Marshal.ReleaseComObject（wb）;
}

else
{
工作簿wb = ExcelApp.Workbooks.Open（文件）;
工作表ws =（工作表）wb.Sheets [ 1 ];
范围= ws.Range [ A1：U35];
range.CopyPicture（XlPictureAppearance.xlScreen，XlCopyPictureFormat.xlBitmap）;
wb.Close（SaveChanges： false ）;
Marshal.ReleaseComObject（wb）;
}
}

最后
{
Bitmap image = new 位图（System.Windows.Forms.Clipboard.GetImage（））;
image.Save（ImagePath + Path.GetFileNameWithoutExtension（file）+ 。svg） ;

Marshal.ReleaseComObject（ExcelApp）;
}
}

你能告诉我我在做什么吗错误或我怎么能意识到这一点？

除了BackgroundWorker还有其他方法吗？



提前感谢您的帮助！

您的问题是您无法从多线程应用程序访问剪贴板。使用Thread类，您可以设置它是STA还是MTA ...但是我不认为可以使用backgroundworker类来做到这一点（ c＃ - 如何将后台工作线程设置为单线程单元？ - Stack Overflow [ ^ ]）。



要使用Thread类设置STA，您可以执行以下操作：

线程t = 新线程（AccessClipBoardHere（））; 
 t.SetApartmentState（ApartmentState.STA）; 
 t.Start（）; 

Hello

my program should export certain Excel files from a folder as an image (in SVG format) into another folder. This can be done by the Methods CopyAndSaveTo and ExportRangeAsImage and they do their job.
On the MainWindow I have a button that performs these two functions when it is clicked. I want the User who clicks on this button be informed (Progressbar) how far is this process (Copy + export).
I have tried to realise it using a BackgroundWorker and it works only if I comment the following code (in the Method ExportRangeAsImage):

Bitmap image = new Bitmap(System.Windows.Forms.Clipboard.GetImage());
image.Save(ImagePath + Path.GetFileNameWithoutExtension(file) + ".svg");

Otherwise I get the following error message (
translated from German):

In System.NullReferenceException an exception of type "System.Drawing.dll" has occurred, but was this not processed in the user code.

Additional information: Object reference not set to an object instance.

If a handler is available for this exception, the program may continue to run safely.


Here is the whole code:

private void UpdateDataOfLine1(object sender, ExecutedRoutedEventArgs e)
        {
            string[] files = Directory.GetFiles(RootPath);

            BackgroundWorker worker = new BackgroundWorker();
            worker.WorkerReportsProgress = true;
            worker.DoWork += worker_DoWork;
            worker.ProgressChanged += worker_ProgressChanged;
            worker.RunWorkerAsync();
        }



        void worker_DoWork(object sender, DoWorkEventArgs e)
        {
            string[] files = Directory.GetFiles(RootPath);

            for (int i = 0; i < files.Length; i++)
            {
                if (files[i].Contains("$") || files[i].Contains("~") || files[i].Contains("Thumb"))
                {
                    continue;
                }

                File.Copy(files[i], DestPath + Path.GetFileName(files[i]), true);

                string newFile = DestPath + Path.GetFileName(files[i]);

                ExPortRangeAsImage(newFile);

                (sender as BackgroundWorker).ReportProgress(i);
                Thread.Sleep(100);
            }
        }



        void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            Status.Value = e.ProgressPercentage;
        }


        public void ExPortRangeAsImage(string file)
        {
            var ExcelApp = new Microsoft.Office.Interop.Excel.Application();

            try
            {
                if (file.Contains("BeispielDatei"))
                {
                    Workbook wb = ExcelApp.Workbooks.Open(file);
                    Worksheet ws = (Worksheet)wb.Sheets[1];
                    Range range = ws.Range["A1:U35"];
                    range.CopyPicture(XlPictureAppearance.xlScreen, XlCopyPictureFormat.xlBitmap);
                    wb.Close(SaveChanges: false);
                    Marshal.ReleaseComObject(wb);
                }

                else
                {
                    Workbook wb = ExcelApp.Workbooks.Open(file);
                    Worksheet ws = (Worksheet)wb.Sheets[1];
                    Range range = ws.Range["A1:U35"];
                    range.CopyPicture(XlPictureAppearance.xlScreen, XlCopyPictureFormat.xlBitmap);
                    wb.Close(SaveChanges: false);
                    Marshal.ReleaseComObject(wb);
                }
            }

            finally
            {
                Bitmap image = new Bitmap(System.Windows.Forms.Clipboard.GetImage());
                image.Save(ImagePath + Path.GetFileNameWithoutExtension(file) + ".svg");

                Marshal.ReleaseComObject(ExcelApp);
            }
        }

What I have tried:

private void UpdateDataOfLine1(object sender, ExecutedRoutedEventArgs e)
        {
            string[] files = Directory.GetFiles(RootPath);

            BackgroundWorker worker = new BackgroundWorker();
            worker.WorkerReportsProgress = true;
            worker.DoWork += worker_DoWork;
            worker.ProgressChanged += worker_ProgressChanged;
            worker.RunWorkerAsync();
        }



        void worker_DoWork(object sender, DoWorkEventArgs e)
        {
            string[] files = Directory.GetFiles(RootPath);

            for (int i = 0; i < files.Length; i++)
            {
                if (files[i].Contains("$") || files[i].Contains("~") || files[i].Contains("Thumb"))
                {
                    continue;
                }

                File.Copy(files[i], DestPath + Path.GetFileName(files[i]), true);

                string newFile = DestPath + Path.GetFileName(files[i]);

                ExPortRangeAsImage(newFile);

                (sender as BackgroundWorker).ReportProgress(i);
                Thread.Sleep(100);
            }
        }



        void worker_ProgressChanged(object sender, ProgressChangedEventArgs e)
        {
            Status.Value = e.ProgressPercentage;
        }


        public void ExPortRangeAsImage(string file)
        {
            var ExcelApp = new Microsoft.Office.Interop.Excel.Application();

            try
            {
                if (file.Contains("BeispielDatei"))
                {
                    Workbook wb = ExcelApp.Workbooks.Open(file);
                    Worksheet ws = (Worksheet)wb.Sheets[1];
                    Range range = ws.Range["A1:U35"];
                    range.CopyPicture(XlPictureAppearance.xlScreen, XlCopyPictureFormat.xlBitmap);
                    wb.Close(SaveChanges: false);
                    Marshal.ReleaseComObject(wb);
                }

                else
                {
                    Workbook wb = ExcelApp.Workbooks.Open(file);
                    Worksheet ws = (Worksheet)wb.Sheets[1];
                    Range range = ws.Range["A1:U35"];
                    range.CopyPicture(XlPictureAppearance.xlScreen, XlCopyPictureFormat.xlBitmap);
                    wb.Close(SaveChanges: false);
                    Marshal.ReleaseComObject(wb);
                }
            }

            finally
            {
                Bitmap image = new Bitmap(System.Windows.Forms.Clipboard.GetImage());
                image.Save(ImagePath + Path.GetFileNameWithoutExtension(file) + ".svg");

                Marshal.ReleaseComObject(ExcelApp);
            }
        }

Can you show me what I'm doing wrong or how I can realize it?
Are there other ways than BackgroundWorker?

Thank you in advance for your help!

解决方案

") || files[i].Contains("~") || files[i].Contains("Thumb")) { continue; } File.Copy(files[i], DestPath + Path.GetFileName(files[i]), true); string newFile = DestPath + Path.GetFileName(files[i]); ExPortRangeAsImage(newFile); (sender as BackgroundWorker).ReportProgress(i); Thread.Sleep(100); } } void worker_ProgressChanged(object sender, ProgressChangedEventArgs e) { Status.Value = e.ProgressPercentage; } public void ExPortRangeAsImage(string file) { var ExcelApp = new Microsoft.Office.Interop.Excel.Application(); try { if (file.Contains("BeispielDatei")) { Workbook wb = ExcelApp.Workbooks.Open(file); Worksheet ws = (Worksheet)wb.Sheets[1]; Range range = ws.Range["A1:U35"]; range.CopyPicture(XlPictureAppearance.xlScreen, XlCopyPictureFormat.xlBitmap); wb.Close(SaveChanges: false); Marshal.ReleaseComObject(wb); } else { Workbook wb = ExcelApp.Workbooks.Open(file); Worksheet ws = (Worksheet)wb.Sheets[1]; Range range = ws.Range["A1:U35"]; range.CopyPicture(XlPictureAppearance.xlScreen, XlCopyPictureFormat.xlBitmap); wb.Close(SaveChanges: false); Marshal.ReleaseComObject(wb); } } finally { Bitmap image = new Bitmap(System.Windows.Forms.Clipboard.GetImage()); image.Save(ImagePath + Path.GetFileNameWithoutExtension(file) + ".svg"); Marshal.ReleaseComObject(ExcelApp); } }

What I have tried:

private void UpdateDataOfLine1(object sender, ExecutedRoutedEventArgs e)
        {
            string[] files = Directory.GetFiles(RootPath);

            BackgroundWorker worker = new BackgroundWorker();
            worker.WorkerReportsProgress = true;
            worker.DoWork += worker_DoWork;
            worker.ProgressChanged += worker_ProgressChanged;
            worker.RunWorkerAsync();
        }



        void worker_DoWork(object sender, DoWorkEventArgs e)
        {
            string[] files = Directory.GetFiles(RootPath);

            for (int i = 0; i < files.Length; i++)
            {
                if (files[i].Contains("

") || files[i].Contains("~") || files[i].Contains("Thumb")) { continue; } File.Copy(files[i], DestPath + Path.GetFileName(files[i]), true); string newFile = DestPath + Path.GetFileName(files[i]); ExPortRangeAsImage(newFile); (sender as BackgroundWorker).ReportProgress(i); Thread.Sleep(100); } } void worker_ProgressChanged(object sender, ProgressChangedEventArgs e) { Status.Value = e.ProgressPercentage; } public void ExPortRangeAsImage(string file) { var ExcelApp = new Microsoft.Office.Interop.Excel.Application(); try { if (file.Contains("BeispielDatei")) { Workbook wb = ExcelApp.Workbooks.Open(file); Worksheet ws = (Worksheet)wb.Sheets[1]; Range range = ws.Range["A1:U35"]; range.CopyPicture(XlPictureAppearance.xlScreen, XlCopyPictureFormat.xlBitmap); wb.Close(SaveChanges: false); Marshal.ReleaseComObject(wb); } else { Workbook wb = ExcelApp.Workbooks.Open(file); Worksheet ws = (Worksheet)wb.Sheets[1]; Range range = ws.Range["A1:U35"]; range.CopyPicture(XlPictureAppearance.xlScreen, XlCopyPictureFormat.xlBitmap); wb.Close(SaveChanges: false); Marshal.ReleaseComObject(wb); } } finally { Bitmap image = new Bitmap(System.Windows.Forms.Clipboard.GetImage()); image.Save(ImagePath + Path.GetFileNameWithoutExtension(file) + ".svg"); Marshal.ReleaseComObject(ExcelApp); } }

Can you show me what I'm doing wrong or how I can realize it?
Are there other ways than BackgroundWorker?

Thank you in advance for your help!

Your issue is that you cannot access the clip board from a multi threaded application. Using the Thread class you can set whether it is STA or MTA...however i don't think it is possible to do that using the backgroundworker class (c# - How can I make a background worker thread set to Single Thread Apartment? - Stack Overflow[^]).

To set STA using Thread class you can do something like:

Thread t = new Thread(AccessClipBoardHere());
t.SetApartmentState(ApartmentState.STA);
t.Start();

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