Tips dan Trik VB.NET

Hari ini, saya ingin menunjukkan sedikit trik dalam pemrograman VB.NET, periksa koneksi internet, dapatkan serial hard drive, salin teks dari clipboard, dapatkan resolusi layar, dll.

1. Periksa koneksi internet.

Public Function IsConnectionAvailable() As Boolean
        Dim objUrl As New System.Uri("http://www.youtube.com")
        Dim objWebReq As System.Net.WebRequest
        objWebReq = System.Net.WebRequest.Create(objUrl)
        Dim objresp As System.Net.WebResponse
  
        Try
            objresp = objWebReq.GetResponse
            objresp.Close()
            objresp = Nothing
            Return True
  
        Catch ex As Exception
            objresp = Nothing
            objWebReq = Nothing
            Return False 
        End Try
End Function

Gunakan fungsi tes koneksi internet sebagai berikut:

If IsConnectionAvailable() = TrueThen
Do Action Here
Else
Do Action Here
  
End If

2. Dapatkan resolusi layar yang digunakan

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        TextBox1.Text = Screen.PrimaryScreen.WorkingArea.Width
        TextBox2.Text = Screen.PrimaryScreen.WorkingArea.Height
End Sub

3. Dapatkan serial hard drive HDD

Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim hd As New ManagementObjectSearcher("SELECT * FROM Win32_PhysicalMedia")
        For Each dvs As ManagementObject In hd.Get()
            Dim serial As String = dvs("SerialNumber").ToString()
            TextBox1.Text = serial
        Next
End Sub

4. Jalankan aplikasi dari program

Misalnya, di bawah ini ketika mengklik tombol akan membuka bab saya microsoft paint

Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
        Shell("mspaint")
End Sub

5. Buka file musik di drive

My.Computer.Audio.Play("C:MusicMusic.wav")

6. Salin teks dari clipboard

If My.Computer.Clipboard.ContainsText Then
TextBox1.Text = My.Computer.Clipboard.GetText
End If

7. Buka bip dari suara sistem windows

My.Computer.Audio.PlaySystemSound(Media.SystemSounds.Beep)

8. Buka situs web dari LabelLink

Private Sub LinkLabel1_LinkClicked(ByVal sender As System.Object, ByVal e As System.Windows.Forms.LinkLabelLinkClickedEventArgs) Handles LinkLabel1.LinkClicked
System.Diagnostics.Process.Start("http://www.domain.com")
End Sub

9. Hasilkan nomor acak

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim number As Integer
  
        Randomize()
        ' The program will generate a number from 0 to 50
        number = Int(Rnd() * 50) + 1
  
        TextBox1.Text = number
End Sub

10. Tekan Alt + PrintScreen untuk mengambil tangkapan layar dan menyimpan file gambar ke drive

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
'send keys with Alt key
SendKeys.SendWait("%({PRTSC})")
My.Computer.Clipboard.GetImage().Save("C:form.jpg")
 
End Sub

11. Dapatkan informasi Ram dari komputer

Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
    TextBox1.Text = My.Computer.Info.TotalPhysicalMemory
    TextBox2.Text = My.Computer.Info.AvailablePhysicalMemory
    TextBox3.Text = My.Computer.Info.TotalVirtualMemory
    TextBox4.Text = My.Computer.Info.AvailableVirtualMemory
End Sub

12. SendKeys

Misalnya, tekan tombol BackSpace.

Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        My.Computer.Keyboard.SendKeys("{BACKSPACE}")
End Sub

Kode lain yang bisa anda gunakan.

BACKSPACE {BACKSPACE} or {BS}
BREAK {BREAK}
CAPS LOCK {CAPSLOCK}
CLEAR {CLEAR}
DELETE {DELETE} or {DEL}
DOWN ARROW {DOWN}
END {END}
ENTER (numeric keypad) {ENTER}
ENTER ~ ESC {ESCAPE} or {ESC}
HELP {HELP}
HOME {HOME}
INS {INSERT}
LEFT ARROW {LEFT}
NUM LOCK {NUMLOCK}
PAGE DOWN {PGDN}
PAGE UP {PGUP}
RETURN {RETURN}
RIGHT ARROW {RIGHT}
SCROLL LOCK {SCROLLLOCK} T
AB {TAB}
UP ARROW {UP}
F1 ke F15 {F1} ke {F15}

13. fungsi enkripsi SHA1.

Public Function SHA1(ByVal number As String) As String
            Dim ASCIIENC As New ASCIIEncoding
            Dim strreturn As String
            strreturn = vbNullString
            Dim bytesourcetxt() As Byte = ASCIIENC.GetBytes(number)
            Dim SHA1Hash As New SHA1CryptoServiceProvider
            Dim bytehash() As Byte = SHA1Hash.ComputeHash(bytesourcetxt)
            For Each b As Byte In bytehash
                strreturn &= b.ToString("X8")
            Next
            Return strreturn
End Function

14. Tampilkan Desktop

Private Declare Sub keybd_event Lib "user32" (ByVal bVk As Byte, ByVal bScan As Byte, ByVal dwFlags As Long, ByVal dwExtraInfo As Long)
    Private Const KEYEVENTF_KEYUP = &H2
    Private Const VK_LWIN = &H5B

Public Sub ShowDesktop()
     keybd_event(VK_LWIN, 0, 0, 0)
     keybd_event(77, 0, 0, 0)
     keybd_event(VK_LWIN, 0, KEYEVENTF_KEYUP, 0)
End Sub

15. Dapatkan jalur dari folder khusus misalnya: Desktop

Dim DesktopPath As String = CreateObject("WScript.Shell").Specialfolders(10)
'OR
Dim DesktopPath As String = System.Environment.GetFolderPath(Environment.SpecialFolder.Desktop)
MsgBox(DesktopPath)

16. Dapatkan event KeyPress saat tombol ditekan

Private Sub Form1_KeyPress(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles MyBase.KeyPress
        If Asc(e.KeyChar) > 1 Then
            MsgBox("You have pressed " & e.KeyChar & " key")
            e.Handled = True
        End If
End Sub

17. Kosongkan semua TextBox didalam form

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
 
        Dim a As Control
 
        For Each a In Me.Controls
 
            If TypeOf a Is TextBox Then
 
                a.Text = Nothing
 
            End If
 
        Next
 
    End Sub

18. Hapus nomor dari TextBox

mis: nguyenthao2803 => nguyenthao

Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click
        Dim rep As String = String.Empty
        For i As Integer = 0 To TextBox1.Text.Length - 1
            If Not IsNumeric(TextBox1.Text.Substring(i, 1)) Then
                rep += TextBox1.Text.Substring(i, 1)
            End If
        Next
        TextBox1.Text = rep
End Sub

19. Teks ukuran font otomatis agar sesuai dengan TextBox

Dim h As String
Dim w As String

Private Sub Form1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles MyBase.Paint
        Dim orgFont As New Font(TextBox1.Font.Name, TextBox1.Font.Size, TextBox1.Font.Style)
        Dim textSize As New SizeF
        textSize = e.Graphics.MeasureString(TextBox1.Text, orgFont)
        h = textSize.Height
        w = textSize.Width
End Sub

Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
        TextBox1.Font = New Font(TextBox1.Font.Name, 8, TextBox1.Font.Style)
        TextBox1.BorderStyle = BorderStyle.Fixed3D
        Do Until w > TextBox1.Size.Width - 5 Or TextBox1.Text = Nothing Or h > 182
            TextBox1.Font = New Font(TextBox1.Font.Name, TextBox1.Font.Size + 2, TextBox1.Font.Style)
        Loop
        TextBox1.BorderStyle = BorderStyle.None
End Sub

20. Hanya boleh input angka di TextBox

Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
        If Asc(e.KeyChar) <> 13 AndAlso Asc(e.KeyChar) <> 8 AndAlso Not IsNumeric(e.KeyChar) Then
            MessageBox.Show("Please enter numbers only")
            e.Handled = True
        End If
End Sub

21. Unduh file dari situs web

My.Computer.Network.DownloadFile("http://www.domain.com/file.txt", _
 "C:yourpathfile.txt")

22. Unggah file ke situs web

My.Computer.Network.UploadFile("C:locationfile.xxx", _
 "ftp://domain.com/www/file.xxx", _
  "username", "password", True, 500)

23. Dapatkan semua link/url dari situs web

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim a As Integer
        Dim b As String
        For a = 1 To WebBrowser1.Document.Links.Count - 1
            b = b & WebBrowser1.Document.Links(a).InnerHtml & vbCrLf
        Next
  
        TextBox1.Text = b
        Label1.Text = WebBrowser1.Document.Links.Count & " links."
End Sub

24. Periksa apakah file tersebut ada atau tidak

If My.Computer.FileSystem.FileExists("C:locationfile.xxx") Then
'file does exist
'/ Do Action
 
Else
' file doesn't exist
End If

25. Salin file dari satu folder ke folder lain

My.Computer.FileSystem.CopyFile("C:yourLocationfile.xxx", "C:NewLocationfile.xxx") 

26. Baca file teks ke dalam kotak teks

TextBox1.Text = My.Computer.FileSystem.ReadAllText("C:your pathfile.txt")

27. Tulis file teks dari Textbox

My.Computer.FileSystem.WriteAllText("C:locationfile.txt", TextBox1.Text, True)

28. Menghapus folder folder

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
 
My.Computer.FileSystem.DeleteDirectory ("C:PathFolder", FileIO.DeleteDirectoryOption.DeleteAllContents)
 
End Sub

29. Membalikkan string

Contoh: Halo => olleH

Public Class Form1
    Dim textToReverse As String
    Dim Letters() As Char
   
    Private Sub Button1_Click(ByVal sender As System.Object, _
     ByVal e As System.EventArgs) Handles Button1.Click
        textToReverse = TextBox1.Text
        Letters = textToReverse.ToCharArray()
        Array.Reverse(Letters)
        Dim ReversedText As New String(Letters, 0, Letters.Length)
        TextBox2.Text = ReversedText
    End Sub
End Class

30. Membalikkan gambar

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim pic As New Bitmap(PictureBox1.Image)
        For y As Integer = 0 To pic.Height - 1
            For x As Integer = 0 To pic.Width - 1
                Dim inv As Color = pic.GetPixel(x, y)
                inv = Color.FromArgb(255, 255 - inv.R, 255 - inv.G, 255 - inv.B)
                pic.SetPixel(x, y, inv)
                PictureBox2.Image = pic
            Next x
        Next y
    End Sub

31. Menampilkan gambar dari clipboard ke dalam kotak Gambar

If My.Computer.Clipboard.ContainsImage Then
    PictureBox1.Image = My.Computer.Clipboard.GetImage
End If

Clipboard.Clear()

SEMOGA BERMANFAAT.