dotnet调用win32 api实现文件搜索

写了一个文件搜索的模块，原用dotnet的System.IO中的接口实现的，发现不支持通配符搜索，只好改用winapi又写一个。

以下是代码片段：

//win32 api 需要一个结构返回查找文件的信息
    [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
    public struct WIN32_FIND_DATA
    ...{
        public FileAttributes dwFileAttributes;
        public FILETIME ftCreationTime;
        public FILETIME ftLastAccessTime;
        public FILETIME ftLastWriteTime;
        public int nFileSizeHigh;
        public int nFileSizeLow;
        public int dwReserved0;
        public int dwReserved1;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_PATH)]
        public string cFileName;
        [MarshalAs(UnmanagedType.ByValTStr, SizeConst = MAX_ALTERNATE)]
        public string cAlternate;
    }

    //从 kernel32.DLL 导出的函数FindFirstFile进行调用
    [DllImport("kernel32", CharSet = CharSet.Unicode)]
    public static extern IntPtr FindFirstFile(string lpFileName, out WIN32_FIND_DATA lpFindFileData);

    //从 kernel32.DLL 导出的函数FindNextFile进行调用
    [DllImport("kernel32", CharSet = CharSet.Unicode)]
    public static extern bool FindNextFile(IntPtr hFindFile, out WIN32_FIND_DATA lpFindFileData);


    protected void btFind_Click(object sender, EventArgs e)
    ...{
        try
        ...{
            if (!Directory.Exists(txDirectoryName.Text.Trim()))
            ...{
                this.lbError.Text = "路径" + txDirectoryName.Text + "不存在.";
                return;
            }

            findFile(dtResult, txDirectoryName.Text.Trim(), txFileName.Text.Trim());
            if (dtResult.Rows.Count == 0)
            ...{
                this.lbError.Text = "文件不存在.";
                return;
            }
            resultGridView.DataSource = dtResult.DefaultView;
            resultGridView.DataBind();
        }
        catch (Exception ex)
        ...{
            lbError.Text = ex.Message;
        }
    }

//提供路径和文件名查找文件
    private void findFile(DataTable dataTable, string path, string fileName)
    ...{
        try
        ...{
            string[] paths = Directory.GetDirectories(path);
            IntPtr INVALID_HANDLE_VALUE = new IntPtr(-1);
            WIN32_FIND_DATA findData;

            IntPtr findHandle;

            findHandle = FindFirstFile(Path.Combine(path,fileName), out findData);
            if (findHandle != INVALID_HANDLE_VALUE)
            ...{
                if (findData.dwFileAttributes.ToString().IndexOf("Directory") == -1)
                ...{
                    DataRow row = dataTable.NewRow();
                    row["fileName"] = findData.cFileName;
                    row["path"] = path;
                    dataTable.Rows.Add(row);
                }
                while (FindNextFile(findHandle, out findData))
                ...{
                    if (findData.dwFileAttributes.ToString().IndexOf("Directory") == -1)
                    ...{
                        DataRow nrow = dataTable.NewRow();
                        nrow["fileName"] = findData.cFileName;
                        nrow["path"] = path;
                        dataTable.Rows.Add(nrow);
                    }
                }
            }
            
            for (int i = 0; i < paths.Length; i++)
            ...{
                findFile(dataTable, Path.Combine(path, paths[i]), fileName);
            }
        }
        catch (Exception ex)
        ...{
            //当在查找特殊目录，如RECYCLER，System Volume Information，系统会抛弃权限不足的异常
            //throw new Exception("查找文件出错");
            //throw ex;
        }
    }