private void sha1CalculateHashBtn_Click(object sender, EventArgs e)
{
var ready = true;
if (string.IsNullOrWhiteSpace(sha1PlainFile.Text))
{
MessageBox.Show("Choose a file for encryption", "Choose plain text", MessageBoxButtons.OK,
MessageBoxIcon.Warning);
ready = false;
}
if (string.IsNullOrWhiteSpace(sha1HashFile.Text))
{
sha1HashFile.Text = _initialDirectory + "SHA_hash.txt";
}
if (ready)
{
SHA1.CalculateHash(sha1PlainFile.Text, sha1HashFile.Text);
}
}