如何在FileInfo中获取文件大小？

Question

I want to get the size to show in the ListView. But my code return 0. I find.Length() get length size but only have Count() and it can't resolve my problem.

My code like:

string[] filePaths = (string[])e.Data.GetData(DataFormats.FileDrop, false);
List<FileInfo> fileInfos = new List<FileInfo>();  
foreach (string filePath in filePaths)
{
    FileInfo f = new FileInfo(filePath);
    fileInfos.Add(f);
    long s1 = fileInfos.Count;
    string chkExt = Path.GetExtension(f.ToString());
    s1 = s1/1024;
    decimal d = default(decimal);
    d = decimal.Round(s1, 2, MidpointRounding.AwayFromZero);
    // d is 0. Because s1 = 1 only count not length of file.

Answer 1

You are using fileInfos , which is a List<T> . You want to check the length of your actual FileInfo f :

long s1 = f.Length;

While you are dividing by 1024, please note, that there is a difference in units when dealing with filezises, depending on your base: 2 or 10. KB is 2^x and kB is 10^x bytes.

Answer 2

you can get the file size in bytes using Length

FileInfo f = new FileInfo(filePath);
long fileSize = f.Length;

Answer 3

The long s1 = fileInfos.Count; doesn't check the file length. It checks the number of members of the fileInfos List . If you want to get individual file length of the files in your List . Do this:

int index = 0; //zero is an example
long fileLength = fileInfos[index].Length;

or in your loop

long fileLength = f.Length;

Also, beware of your operation:

s1 = s1/1024;

Since s1 is a long , you will lose some precision here... maybe you can consider to use decimal for s1 from the beginning

Answer 4

FileInfo fileInfo = new FileInfo(path); 
long fileLength = fileInfo.Length;

would give the size of the file. It is better to check whether the file exists or not before getting the size to avoid FileNotFound exception.