multiples patterns in File Dialog

[PhillipBrooks]

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BruceMoyer wrote:
Could someone show me where this feature is documented? I've been trying to do this for as long as I've been using LabVIEW (about 13 years) and have never been able to figure out how to do this!

Bruce

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If you are referring to the multiple patterns, it is stated in the help:

http://zone.ni.com/reference/en-XX/help/371361E-01/glang/file_dialog/#Inputs

pattern (all files)

Restricts the files displayed in the dialog box to those whose name matches pattern (all files). pattern (all files) does not restrict the directories displayed. The pattern matching in this VI is similar to the matching used in matching wildcards in Windows and Linux filenames. If you specify characters other than the question mark character (?) or the asterisk character (*), the VI displays only files or directories that contain those characters. You can use the question mark character (?) to match any single character. You can use the asterisk character (*) to match any sequence of one or more characters. For example, a pattern (all files) of *.vi;test*.llb returns matches for any file with a .vi extension and any file whose filename begins with test and has a .llb extension. To match multiple patterns, use a semicolon ( ; ) to separate the patterns. White space, such as blanks, tabs, and carriage returns, are taken literally. Avoid using white spaces unless they are part of the extension pattern. For example, if you use *.html;*.doc, the dialog box displays all files that end with .html and .doc. If you use *.html; *.doc, the dialog box displays only files that end with .html.

[BruceMoyer]

That I knew about.  I was referring to the ability to have multiple selections in the "Files of type:" dropdown in the File dialog.

The example that MikaelH gave uses the NULL ASCII character (\00) to create addition selections.

*.txt;*.doc;*.html)\00*.txt;*.doc;*.html;\00Image\sfiles\s(*.png;*.jpg)\00*.png;*.jpg\00\00

I don't see info about using this strategy anywhere.

Bruce

[PhillipBrooks]

It took me a while to find it, but if you are a Mac user, there was a bug with multiple patterns...

[BruceMoyer]

This technique even works in LabVIEW 7.1 (the earliest version I have installed), which means that this isn't a newly implemented trick!

Bruce

[PhillipBrooks]

The string looks very similar to that of the Windows OpenDialog Class; just replace the pipe with a NULL

private void button1_Click(object sender, System.EventArgs e)
{
    Stream myStream = null;
    OpenFileDialog openFileDialog1 = new OpenFileDialog();

    openFileDialog1.InitialDirectory = "c:\\" ;
    openFileDialog1.Filter = "txt files (*.txt)|*.txt|All files (*.*)|*.*" ;
    openFileDialog1.FilterIndex = 2 ;
    openFileDialog1.RestoreDirectory = true ;

    if(openFileDialog1.ShowDialog() == DialogResult.OK)
    {
        try
        {
            if ((myStream = openFileDialog1.OpenFile()) != null)
            {
                using (myStream)
                {
                    // Insert code to read the stream here.
                }
            }
        }
        catch (Exception ex)
        {
            MessageBox.Show("Error: Could not read file from disk. Original error: " + ex.Message);
        }
    }
}

[BruceMoyer]

That's interesting.  Regardless, it should be added to the help and/or the functionality added to the Express VI.

Thanks,

Bruce

[rolfk]

This is the string format as it is put in the Windows API FileDialog structure, which this function ultimately uses under Windows. The matching with the .Net class is not coincidence, but they had to use a different charcter than \0 since .Net also treats 0 characters as string terminanation (LabVIEW doesn't as its strings contain an explicit length parameter). .Net clearly calls the Windows API too, simply replacing all pipe symbols with a 0 character just before sending it off.

As such this is likely is a side effect of LabVIEW not terminating on 0 characters rather than intended behaviour and what is worse it is Windows only. So documenting it would mean that they would have to implement it on non-Windows platforms too and likely they would go the route of .Net using for instance the pipe symbol for that on all platforms.

Message Edited by rolfk on 05-05-2010 12:53 AM