我有一个应用程序,每当我正在观察的日志文件以以下方式更新(附加了新文本)时,它就会更新我的datagrid:
private void DGAddRow(string name, FunctionType ft)
{
ASCIIEncoding ascii = new ASCIIEncoding();
CommDGDataSource ds = new CommDGDataSource();
int position = 0;
string[] data_split = ft.Data.Split(' ');
foreach (AttributeType at in ft.Types)
{
if (at.IsAddress)
{
ds.Source = HexString2Ascii(data_split[position]);
ds.Destination = HexString2Ascii(data_split[position+1]);
break;
}
else
{
position += at.Size;
}
}
ds.Protocol = name;
ds.Number = rowCount;
ds.Data = ft.Data;
ds.Time = ft.Time;
dataGridRows.Add(ds);
rowCount++;
}
...
private void FileSystemWatcher()
{
FileSystemWatcher watcher = new FileSystemWatcher(Environment.CurrentDirectory);
watcher.Filter = syslogPath;
watcher.NotifyFilter = NotifyFilters.LastAccess | NotifyFilters.LastWrite
| NotifyFilters.FileName | NotifyFilters.DirectoryName;
watcher.Changed += new FileSystemEventHandler(watcher_Changed);
watcher.EnableRaisingEvents = true;
}
private void watcher_Changed(object sender, FileSystemEventArgs e)
{
if (File.Exists(syslogPath))
{
string line = GetLine(syslogPath,currentLine);
foreach (CommRuleParser crp in crpList)
{
FunctionType ft = new FunctionType();
if (crp.ParseLine(line, out ft))
{
DGAddRow(crp.Protocol, ft);
}
}
currentLine++;
}
else
MessageBox.Show(UIConstant.COMM_SYSLOG_NON_EXIST_WARNING);
}
当为FileWatcher引发事件时,因为它创建了一个单独的线程,所以当我尝试运行dataGridRows.Add(Ds)时;为了添加新行,程序在调试模式期间崩溃,没有给出任何警告。
在Winforms中,使用Invoke函数可以很容易地解决这个问题,但我不确定在WPF中该如何处理。
发布于 2012-07-24 14:25:00
您可以使用
Dispatcher.Invoke(Delegate, object[])
在Application
的(或任何UIElement
的)调度器上。
例如,您可以像这样使用它:
Application.Current.Dispatcher.Invoke(new Action(() => { /* Your code here */ }));
或
someControl.Dispatcher.Invoke(new Action(() => { /* Your code here */ }));
发布于 2012-07-24 14:31:33
最好的方法是从UI线程获取一个SynchronizationContext
并使用它。这个类抽象了对其他线程的编组调用,使测试变得更容易(与直接使用WPF的Dispatcher
形成对比)。例如:
class MyViewModel
{
private readonly SynchronizationContext _syncContext;
public MyViewModel()
{
// we assume this ctor is called from the UI thread!
_syncContext = SynchronizationContext.Current;
}
// ...
private void watcher_Changed(object sender, FileSystemEventArgs e)
{
_syncContext.Post(o => DGAddRow(crp.Protocol, ft), null);
}
}
https://stackoverflow.com/questions/11625208
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