我正在尝试从FileSystemWatcher对象OnChanged事件更新toolStripStatusLabel文本，但我无法完成它。
尝试了这段代码，但最好的方法是什么？ 我在没有显示文本的行上遇到问题。 （没有错误只是没有txt）
toolStripStatusLabel.Text = txt + " " + newfile;
源代码：
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
}
}
答案 0 :(得分：2)
静态方法无法访问toolStripStatusLabel等成员，因为它不是该实例的一部分。
要继续你的方式，你的“TheIncomingDataClass”应该引用它应该与之接口的MainForm对象。当您创建此类的实例（可能来自MainForm的实例方法）时，您需要传入对此MainForm对象的引用。
class TheIncomingDataClass{
MainForm form;
public TheIncomingDataClass(MainForm form){
this.form = form;
}
}
class MainForm : Form{
MainForm(){
new TheIncomingDataClass(this);
}
}
然而，正如Bugs所建议的那样，你可能最好在TheIncomingDataClass上创建一个事件并从MainForm订阅它。
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());
}
}