VB.NET For Each - vb.net

Question

After finally fixing my last problem, the code that I ended with was
Function MD5(ByVal strToHash As String) As String
Dim md5Obj As New Security.Cryptography.MD5CryptoServiceProvider
Dim bytesToHash() As Byte = System.Text.Encoding.ASCII.GetBytes(strToHash)
bytesToHash = md5Obj.ComputeHash(bytesToHash)
Dim strResult As String = ""
For Each b As Byte In bytesToHash
strResult += b.ToString("x2")
Next
Return strResult
End Function
Dim words As IEnumerable(Of String) = File.ReadLines(OpenFileDialog1.FileName)
For Each word As String In words
If String.Equals(MD5(word), hash.Text) Then
Label2.Text = word
Else : Label2.Text = "Hash Could Not Be Cracked"
End If
Next
Now I need to make it stop once the hashed word matches the hash I typed in!

Answer 1

To stop a loop, use Exit For:
Dim words As IEnumerable(Of String) = File.ReadLines(OpenFileDialog1.FileName)
For Each word As String In words
If MD5(word) = hash.Text Then
Label2.Text = word
Exit For
Else : Label2.Text = "Hash Could Not Be Cracked"
End If
Next
But note that the Else makes no sense here (the form won’t be updated until after the method is left) and that String.Equals can be replaced here by = (I’ve already done that).

Answer 2

You could use LINQ's FirstOrDefault, since you're using ReadLines instead of ReadAllLines anyway:
Dim firstWord = (From line In IO.File.ReadLines(OpenFileDialog1.FileName)
Where String.Equals(MD5(line), hash.Text)).FirstOrDefault()
If firstWord IsNot Nothing Then
Label2.Text = firstWord
Else
Label2.Text = "Hash Could Not Be Cracked"
End If
Another way is a simple loop:
Dim lines = IO.File.ReadAllLines(OpenFileDialog1.FileName)
Dim matchingLine As String = Nothing
For i = 0 To lines.Length -1
Dim line = lines(i)
If String.Equals(MD5(line), hash.Text)) Then
matchingLine = line
Exit For
End If
Next
If matchingLine IsNot Nothing Then
Label2.Text = matchingLine
Else
Label2.Text = "Hash Could Not Be Cracked"
End If