Find Text: Previous

I'm making a notepad program and i want the user to be able to search for text. I got the code working for the "Find Next" button, but I cant get the code for the "Find Previous" button.

Here's what I have for Find Next:

Code:

---

Private Sub btnNext_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnNext.Click

        Dim x As Integer
        Dim opt As RichTextBoxFinds = 0
        If chkCase.Checked Then opt = opt Or RichTextBoxFinds.MatchCase
        x = CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Find(txtFind.Text, PlaceHolder, opt)
        If x < 0 Then
            If MessageBox.Show("There are no more occurances of " & txtFind.Text & vbCrLf & "Start at begining?", "Can't Find", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button1) = Windows.Forms.DialogResult.Yes Then
                PlaceHolder = 0
                btnNext.PerformClick()
            End If
        End If
        PlaceHolder = CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).SelectionStart + 1
        CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Focus()

    End Sub

---

Here's what I have for Find Previous:
I just can't seem to make it work. I've been messing with it and trying all sorts of different options, it just keeps messing up.

Code:

---

Private Sub btnPrevious_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnPrevious.Click
        Dim x As Integer
        Dim opt As RichTextBoxFinds = 0
        If chkCase.Checked Then opt = opt Or RichTextBoxFinds.MatchCase
        x = CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Find(txtFind.Text, PlaceHolder, opt)
        If x < 0 Then
            If MessageBox.Show("There are no more occurrences of " & txtFind.Text & vbCrLf & "Start at begining?", "Word or Phrase Not Found", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button1) = Windows.Forms.DialogResult.Yes Then
                PlaceHolder = 0
                btnNext.PerformClick()
            End If
        End If
        PlaceHolder = CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).SelectionStart - 1
        CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Focus()

    End Sub

---

Any help is greatly appreciated!

~Thanks in advance

vb Code:

Dim startAt As Integer = 'the position in your text to start from
x = RichTextBox1.Find("a", startAt, RichTextBoxFinds.Reverse)

I already tried that, it doesn't work at all. No matter what the start position is, it always starts at the bottom. And for some reason, it doesn't move up.

Your options are stored in a variable of type RichTextBoxFinds named opt. Let's see how it's set up in both of your methods.

Find next:

Code:

---

Dim opt As RichTextBoxFinds = 0
If chkCase.Checked Then opt = opt Or RichTextBoxFinds.MatchCase

---

So in this case it does whatever 0, or 0 OR MatchCase does. You have to turn to disassembly to know what that is for sure; in this case you get 0 or 4; None or MatchCase.

Find previous:

Code:

---

Dim opt As RichTextBoxFinds = 0
If chkCase.Checked Then opt = opt Or RichTextBoxFinds.MatchCase

---

Oh dear. It's the same. Perhaps you should try .paul.'s advice, or at least produce the code you have that isn't working so we can determine if there's another problem.

try this:

vb Code:

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
    Dim endAt As Integer = RichTextBox1.Text.Length
    endAt = RichTextBox1.Find("it", 0, endAt, RichTextBoxFinds.Reverse) - 1
    Do While endAt > -1
        RichTextBox1.SelectionFont = New Font(RichTextBox1.Font, FontStyle.Bold)
        endAt = RichTextBox1.Find("it", 0, endAt, RichTextBoxFinds.Reverse) - 1
    Loop
End Sub

the problem with the startAt parameter is if you set it to 100 it'll reverse search from the end of the text to startAt. startAt needs to be 0 + the endAt parameter needs to be 1 char before the last find, then that's where it'll reverse search from...

I still can't get it to work. All it does is highlight the last occurrence every time I hit the button. Here's the new code:

Code:

---

Dim x As Integer
        Dim opt As RichTextBoxFinds = 0
        If chkCase.Checked Then opt = opt Or RichTextBoxFinds.MatchCase

        Dim endAt As Integer = CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Text.Length
        x = CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Find(txtFind.Text, 0, endAt, RichTextBoxFinds.Reverse) - 1
        If x < 0 Then
            If MessageBox.Show("There are no more occurrences of " & txtFind.Text & vbCrLf & "Start at begining?", "Word or Phrase Not Found", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button1) = Windows.Forms.DialogResult.Yes Then
                PlaceHolder = 0
                btnNext.PerformClick()
            End If
        End If

---

I tried copying your code and I couldn't make it work. I want it to start where the 'find next' left off and just move up. I want it to act almost exactly like the find function in windows notepad, except instead of checking 'up' or 'down' - hit next or previous.

it highlights only the last occurrence because you aren't looping

vb Code:

Dim x As Integer
Dim opt As RichTextBoxFinds = RichTextBoxFinds.Reverse
If chkCase.Checked Then opt = opt Or RichTextBoxFinds.MatchCase
 
Dim endAt As Integer = CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Text.Length
endAt = CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Find(txtFind.Text, 0, endAt, opt) - 1
Do While endAt > -1
    endAt = CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Find(txtFind.Text, 0, endAt, opt) - 1
    If x < 0 Then
        If MessageBox.Show("There are no more occurrences of " & txtFind.Text & vbCrLf & "Start at begining?", "Word or Phrase Not Found", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button1) = Windows.Forms.DialogResult.Yes Then
            PlaceHolder = 0
            btnNext.PerformClick()
        End If
    End If
Loop

But because that code loops, it reads from the bottom until it reaches the top doesn't it?

I need it to stop and highlight the occurrence before the present one. So if I had:

abc
abc
abc
abc

I hit 'find next' 3 times and the third one down is highlighted. When I hit 'find previous' I want the second one down to be highlighted. So I changed the code to this:

vb Code:

Dim x As Integer
        Dim opt As RichTextBoxFinds = RichTextBoxFinds.Reverse
        If chkCase.Checked Then opt = opt Or RichTextBoxFinds.MatchCase
        Dim endAt As Integer = CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Text.Length
        endAt = CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Find(txtFind.Text, 0, endAt, opt) - 1
        Do While endAt > PlaceHolder - 1
            endAt = CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Find(txtFind.Text, 0, endAt, opt) - 1
            If x < 0 Then
                If MessageBox.Show("There are no more occurrences of " & txtFind.Text & vbCrLf & "Start at begining?", "Word or Phrase Not Found", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button1) = Windows.Forms.DialogResult.Yes Then
                    PlaceHolder = 0
                    btnNext.PerformClick()
                End If
            End If
        Loop
        CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Focus()

But now it just highlights the same one as the 'find next' button does.

Thank you by the way for all the help. I'm much closer now than I was before!

Ok this code works almost the way I want it. After you hit the button once, it re-highlights the text-- then after you hit it again it moves up.

vb Code:

On Error Resume Next
 
        Dim x As Integer
        Dim opt As RichTextBoxFinds = RichTextBoxFinds.Reverse
        If chkCase.Checked Then opt = opt Or RichTextBoxFinds.MatchCase
        Dim endAt As Integer = CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Text.Length
        endAt = CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Find(txtFind.Text, 0, endAt, opt) - 1
        Do While endAt > PlaceHolder - 2
            endAt = CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Find(txtFind.Text, 0, endAt, opt) - 1
            If x < 0 Then
                If MessageBox.Show("There are no more occurrences of " & txtFind.Text & vbCrLf & "Start at begining?", "Word or Phrase Not Found", MessageBoxButtons.YesNo, MessageBoxIcon.Question, MessageBoxDefaultButton.Button1) = Windows.Forms.DialogResult.Yes Then
                    PlaceHolder = 0
                    btnNext.PerformClick()
                End If
            End If
        Loop
        PlaceHolder -= 3
        CType(frmMain.TabControl.SelectedTab.Controls.Item(0), RichTextBox).Focus()