C# 如何获取StreamWriter的完整路径
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原文地址: http://stackoverflow.com/questions/10483314/
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How to get full path of StreamWriter
提问by javapowered
I'm creating a StreamWriterusing a relative path. But the file doesn't appear. To troubleshoot, I want to check that the full path is what I'm expecting. So having a StreamWriterinstance, how can I get the full path of the file it's going to write to?
我正在StreamWriter使用相对路径创建一个。但是文件没有出现。要进行故障排除，我想检查完整路径是否符合我的预期。那么有一个StreamWriter实例，我怎样才能获得它要写入的文件的完整路径？
string fileName = "relative/path.txt"
StreamWriter sw= new StreamWriter(fileName);
// What is the full path of 'sw'?
采纳答案by Steve
To get the full path from a relative path, use the Path.GetFullPathmethod.
要从相对路径获取完整路径，请使用Path.GetFullPath方法。
For example:
例如：
string fileName = "relative/path.txt";
string fullPath = Path.GetFullPath(fileName);
回答by RajN
Might be the directory 'relative' not exists. Either create it manually. Or create it programmatically as below
可能是目录“相对”不存在。要么手动创建。或以编程方式创建它，如下所示
string fileName = @"relative\path.txt";
fileName = Path.GetFullPath(fileName);
Directory.CreateDirectory(Path.GetDirectoryName(fileName));
StreamWriter sw= new StreamWriter(fileName, true);
回答by Jeppe Stig Nielsen
In my version of the framework, this seems to work:
在我的框架版本中，这似乎有效：
string fullPath = ((FileStream)(streamWriter.BaseStream)).Name;
(Found by debugging.)
（通过调试找到。）
回答by Serj-Tm
var fstream = sw.BaseStream as System.IO.FileStream;
if (fstream != null)
Console.WriteLine(GetAbsolutePathByHandle(fstream.SafeFileHandle));
[DllImport("ntdll.dll", CharSet = CharSet.Auto)]
private static extern int NtQueryObject(SafeFileHandle handle, int objectInformationClass, IntPtr buffer, int StructSize, out int returnLength);
static string GetAbsolutePathByHandle(SafeFileHandle handle)
{
var size = 1024;
var buffer = Marshal.AllocCoTaskMem(size);
try
{
int retSize;
var res = NtQueryObject(handle, 1, buffer, size, out retSize);
if (res == -1073741820)
{
Marshal.FreeCoTaskMem(buffer);
size = retSize;
Marshal.AllocCoTaskMem(size);
res = NtQueryObject(handle, 1, buffer, size, out retSize);
}
if (res != 0)
throw new Exception(res.ToString());
var builder = new StringBuilder();
for (int i = 4 + (Environment.Is64BitProcess ? 12 : 4); i < retSize - 2; i += 2)
{
builder.Append((char)Marshal.ReadInt16(buffer, i));
}
return builder.ToString();
}
finally
{
Marshal.FreeCoTaskMem(buffer);
}
}
Output:
输出：
\Device\HarddiskVolume2\bla-bla\relative\path.txt
回答by Aave
Dim fs As FileStream = CType(sw.BaseStream, FileStream)
Dim fi As New FileInfo(fs.Name)
Console.WriteLine(fi.FullName)
