OpenFileDialog.OpenFile Method ()

 

Opens the file selected by the user, with read-only permission. The file is specified by the FileName property.

Namespace:   System.Windows.Forms
Assembly:  System.Windows.Forms (in System.Windows.Forms.dll)

public Stream OpenFile()

Return Value

Type: System.IO.Stream

A Stream that specifies the read-only file selected by the user.

Exception Condition
ArgumentNullException

The file name is null.

The OpenFile method is used to provide a facility to quickly open a file from the dialog box. The file is opened in read-only mode for security purposes. To open a file in read/write mode, you must use another method, such as FileStream.

The following code example demonstrates how to use the OpenFile method.

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);
        }
    }
}

FileDialogPermission

to open a file. Associated enumeration: FileDialogPermissionAccess.Open.

.NET Framework
Available since 1.1
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