取文件的大小 （KB,MB,GB...）

2种方式： VB 和 C#

1,  VB

 Public Function GetFileSize(ByVal iFileSizeKB As Long) As String
        Dim iFileSizeMB As Integer
        Dim iFileSizeGB As Integer

        If (iFileSizeKB >= 1024) Then
            iFileSizeMB = iFileSizeKB / 1024
            If (iFileSizeMB >= 1024) Then
                iFileSizeGB = iFileSizeMB / 1024
            End If
        End If

        If (iFileSizeGB > 0) Then
            Return iFileSizeGB.ToString() + " GB"
        ElseIf (iFileSizeMB > 0) Then
            Return iFileSizeMB.ToString() + " MB"
        Else
            Return iFileSizeKB.ToString() + " KB"
        End If
    End Function

2， C#

  public string GetFileSize(string sFileFullName)
        {
            FileInfo fiInput = new FileInfo(sFileFullName);
            double len = fiInput.Length;

            string[] sizes = { "B", "KB", "MB", "GB" };
            int order = 0;
            while (len >= 1024 && order + 1 < sizes.Length)
            {
                order++;
                len = len / 1024;
            }

            string filesize = String.Format("{0:0.##} {1}", len, sizes[order]);
            return filesize;
        }

  public static bool FileIsLargerThan1KB(string sFileFullName)
        {
            FileInfo fiInput = new FileInfo(sFileFullName);
            double len = fiInput.Length;

            len = len / 1024 / 1024;
            return len > 1;
        }

调用方式：