在VB程序中记录日志(log)可以通过以下几种方法实现:
方法一:使用文件操作
创建一个模块 ,例如命名为`LogModule`。编写`WriteLog`子程序
,用于将日志消息写入文件。以下是一个示例代码:
```vb
Public Sub WriteLog(ByVal logMessage As String, Optional ByVal logLevel As String = "INFO")
Dim logPath As String
logPath = ThisWorkbook.Path & "\debug.log"
Dim fileNum As Integer
fileNum = FreeFile
Open logPath For Append As fileNum
Print fileNum, Format(Now, "yyyy-mm-dd hh:mm:ss") & " - " & logLevel & " - " & logMessage
Close fileNum
End Sub
```
方法二:使用`System.Diagnostics.Trace`
创建一个`TextWriterTraceListener`,并将其添加到`Trace`监听器列表中。
使用`Trace.Write`方法记录日志信息。以下是一个示例代码:
```vb
Dim log As System.IO.TextWriter
log = System.IO.File.CreateText("D:/log.txt")
Dim logListener As New System.Diagnostics.TextWriterTraceListener(log)
System.Diagnostics.Trace.AutoFlush = True
System.Diagnostics.Trace.Listeners.Add(logListener)
System.Diagnostics.Trace.Write("Sorry, there are some thing wrong in your Application! Please check it!")
System.Diagnostics.Trace.Close()
log.Close()
```
方法三:使用`System.IO.Directory.CreateDirectory`和`System.IO.File.CreateText`
创建日志文件的目录(如果尚不存在)。
创建一个`TextWriter`对象,并将日志消息写入该文件。以下是一个示例代码:
```vb
Private Sub WriteLog(ByVal Msg As String)
Dim varAppPath As String
varAppPath = System.AppDomain.CurrentDomain.SetupInformation.ApplicationBase + "log"
System.IO.Directory.CreateDirectory(varAppPath)
Dim head As String
head = System.DateTime.Now.Hour.ToString() & " : " & System.DateTime.Now.Minute.ToString() & " : " & System.DateTime.Now.Second.ToString() & " : " & System.DateTime.Now.Millisecond.ToString()
Msg = head & System.Environment.NewLine & Msg & System.Environment.NewLine
Dim logFile As String = System.IO.Path.Combine(varAppPath, "log.txt")
Dim logWriter As New System.IO.StreamWriter(logFile)
logWriter.WriteLine(Msg)
logWriter.Close()
End Sub
```
建议
选择合适的方法: 根据你的需求和项目规模选择最适合的方法。对于简单的日志记录,文件操作方法可能已经足够。对于更复杂的应用程序,使用`System.Diagnostics.Trace`可能更合适,因为它提供了更多的功能和更好的性能。 日志级别
异常处理:在写入日志时,建议添加异常处理,以防止日志文件因错误而损坏。