FileSystemWatcher和toolStripStatusLabel

Question

我想從FileSystemWatcher對象OnChanged事件更新toolStripStatusLabel文本，但我無法完成它。

試過這段代碼，但是最好的辦法是什麼？ 我在沒有顯示文字的行上有問題。 （沒有錯誤只是沒有TXT）

toolStripStatusLabel.Text = txt + " " + newfile; 

源代碼：

using System.IO; 
using System.Runtime.InteropServices; 
using System.Threading; 

namespace Packet 
{ 
public partial class Main 
{ 
    [DllImport("7plus.dll")] 
    public static extern int Do_7plus([MarshalAs(UnmanagedType.LPStr)] string args); 

    #region CreateFile Watch 
    public void CreateFileWatcher(string path) 
    { 
     // Create a new FileSystemWatcher and set its properties. 
     FileSystemWatcher watcher = new FileSystemWatcher 
     { 
      Path = path, 
      NotifyFilter = NotifyFilters.LastWrite, 
      Filter = "*.*" 
     }; 
     watcher.Changed += OnChanged; 
     watcher.EnableRaisingEvents = true; 
    } 
    #endregion 

    #region OnChange 
    private static void OnChanged(object source, FileSystemEventArgs e) 
    { 
     // Specify what is done when a file is changed, created, or deleted. 
     string newfile; 
     string ext = Path.GetExtension(e.FullPath); 
     string file = Path.GetFileNameWithoutExtension(e.FullPath); 
     string path = Path.GetDirectoryName(e.FullPath) + Path.DirectorySeparatorChar; 
     if (ext == ".7pl") 
     { 
      newfile = path + file + ".7pl"; 
      string lockfile = Directory.GetCurrentDirectory() + "\\Data\\Lock\\" + file + ".lock"; 
      string logfile = Directory.GetCurrentDirectory() + "\\Data\\Log\\" + file + ".LOG"; 
      string outpath = Directory.GetCurrentDirectory() + "\\Data\\Out\\" ; 
      if (!File.Exists(lockfile)) 
      { 
       using (File.Create(lockfile)) 
       { 
        var args = newfile + " -SAVE " + outpath + " -LOG " + logfile; 
        Run7Plus(args); 
       } 
      } 
      else 
      { 
       File.Delete(lockfile); 
      } 
     } 
     else if (ext == ".lock" || ext == ".LOG") 
     { } 
     else 
      { 
      newfile = path + file + ".P01"; 
      string lockfile = Directory.GetCurrentDirectory() + "\\Data\\Lock\\" + file + ".lock"; 
      string logfile = Directory.GetCurrentDirectory() + "\\Data\\Log\\" + file + ".LOG"; 
      string outpath = Directory.GetCurrentDirectory() + "\\Data\\Out\\"; 
      if (!File.Exists(lockfile)) 
      { 
       using (File.Create(lockfile)) 
       { 
        var args = newfile + " -SAVE " + outpath + " -LOG " + logfile; 
        Run7Plus(args); 
       } 
      } 
      else 
      { 
       File.Delete(lockfile); 
      } 
     } 
    } 
    #endregion OnChange 

    #region Run 7plus 
    public static void Run7Plus(string newfile) 
    { 
     var args = newfile ; 
     Thread.Sleep(5000); 
     int rn = Do_7plus(args); 

     using (Main main = new Main()) 
     { 
      main.Msg(newfile, rn); 
     } 
    } 
    #endregion 

    #region is File locked 
    protected virtual bool IsFileLocked(FileInfo file) 
    { 
     FileStream stream = null; 
     try 
     { 
      stream = file.Open(FileMode.Open, FileAccess.ReadWrite, FileShare.None); 
     } 
     catch (IOException) 
     { 
      //the file is unavailable because it is: 
      //still being written to 
      //or being processed by another thread 
      //or does not exist (has already been processed) 
      return true; 
     } 
     finally 
     { 
      if (stream != null) 
       stream.Close(); 
     } 
     //file is not locked 
     return false; 
    } 
    #endregion 

    #region msg 
    public void Msg(string newfile, int rn) 
    { 
     string txt; 
     switch (rn) 
     { 
      case 0: 
       { 
        txt = "No errors detected."; 
        break; 
       } 
      case 1: 
       { 
        txt = "Write error."; 
        break; 
       } 
      case 2: 
       { 
        txt = "File not found."; 
        break; 
       } 
      case 3: 
       { 
        txt = "7PLUS header not found."; 
        break; 
       } 
      case 4: 
       { 
        txt = "File does not contain expected part."; 
        break; 
       } 
      case 5: 
       { 
        txt = "7PLUS header corrupted."; 
        break; 
       } 
      case 6: 
       { 
        txt = "No filename for extracting defined."; 
        break; 
       } 
      case 7: 
       { 
        txt = "invalid error report/correction/index file."; 
        break; 
       } 
      case 8: 
       { 
        txt = "Max number of parts exceeded."; 
        break; 
       } 
      case 9: 
       { 
        txt = "Bit 8 stripped."; 
        break; 
       } 
      case 10: 
       { 
        txt = "User break in test_file();"; 
        break; 
       } 
      case 11: 
       { 
        txt = "Error report generated."; 
        break; 
       } 
      case 12: 
       { 
        txt = "Only one or no error report to join."; 
        break; 
       } 
      case 13: 
       { 
        txt = "Error report/cor-file does not refer to the same original file."; 
        break; 
       } 
      case 14: 
       { 
        txt = "Couldn't write 7plus.fls."; 
        break; 
       } 
      case 15: 
       { 
        txt = "File size of original file and the size reported in err/cor-file not equal."; 
        break; 
       } 
      case 16: 
       { 
        txt = "Correction not successful."; 
        break; 
       } 
      case 17: 
       { 
        txt = "No CRC found in err/cor-file."; 
        break; 
       } 
      case 18: 
       { 
        txt = "Time stamp in meta file differs from that in the correction file."; 
        break; 
       } 

      case 19: 
       { 
        txt = "Meta file already exists."; 
        break; 
       } 
      case 20: 
       { 
        txt = "Can't encode files with 0 file length."; 
        break; 
       } 
      case 21: 
       { 
        txt = " Not enough memory available."; 
        break; 
       } 


      default: 
       { 
        txt = "?"; 
        break; 
       } 
     } 
     toolStripStatusLabel1.Text = txt + " " + newfile; 
    } 
    #endregion 

} 
} 

Answer 1

read this

靜態方法不能訪問像toolStripStatusLabel成員，因爲它不是該實例的一部分。

要繼續這樣做，您的「TheIncomingDataClass」應該有一個對應的MainForm對象的引用。當你創建這個類的一個實例（大概來自MainForm的一個實例方法）時，你將需要傳入對這個MainForm對象的引用。

class TheIncomingDataClass{ 
    MainForm form; 

    public TheIncomingDataClass(MainForm form){ 
     this.form = form; 
    } 
} 

class MainForm : Form{ 
    MainForm(){ 
     new TheIncomingDataClass(this); 
    } 
} 

然而，錯誤的建議，你可能會更好做這在TheIncomingDataClass事件和MainForm的訂閱它。

class IncomingMessageEventArgs : EventArgs{ 
    IncomingMessageType message; 

    public IncomingMessageType Message{get{return message;}} 

    public IncomingMessageEventArgs(IncomingMessageType message){ 
     this.message = message; 
    } 
} 

class TheIncomingDataClass{ 
    public event EventHandler<IncomingMessageEventArgs> MessageReceived; 

    protected virtual void OnMessageReceived(IncomingMessageEventArgs e){ 
     if(MessageReceived != null) 
      MessageReceived(this, e); 
    } 

    public void IncomingMessage(IncomingMessageType message){ 
     OnMessageReceived(new IncomingMessageEventArgs(message)); 
    } 
} 

class MainForm : Form{ 
    MainForm(){ 
     new TheIncomingDataClass().MessageReceived += 
      (s, e)=>txtDisplayMessages.AppendText(e.Message.ToString()); 
    } 
}