SendInput - Function to type ASCII characters - where's the flaw?

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Dear friends,

I need to fill a "File Open" dialog box with a string (file path and name).

Since my language has plenty of characters on the extended ASCII - for instance, a file can be named "C:\Hipóteses\Ações de mínima freqüência.doc", i thought of sending all characters in the format "Alt+000" instead of mapping each keyboard combination that produces it. The code to do this follows at the end.

However, this combination doesn't seem to work. I tested it upon a TextBox, and it caught KeyDown and KeyUp events correctly, but the due character doesn't appear :(. Can any of you friends spot the reason?

Thank you very much!

(My specs: VS/VB 2010, .NET 4.0, Windows 8)

vb Code:

Imports System.Runtime.InteropServices
Namespace WinApi
    Module WinApi
        Public Function TypeAscii(ByVal code As Integer) As Boolean
            Dim kc = 96 + (code \ 100) ' key from numeric keyboard, for 1st digit of ASCII code
            Dim kd = 96 + ((code Mod 100) \ 10) ' key from numeric keyboard, for 2nd digit of ASCII code
            Dim ku = 96 + (code Mod 10) ' key from numeric keyboard, for 3rd digit of ASCII code
            Return SendSingleInput(InputKeyDown(18)) AndAlso
                   SendSingleInput(InputKeyDown(kc)) AndAlso
                   SendSingleInput(InputKeyUp(kc)) AndAlso
                   SendSingleInput(InputKeyDown(kd)) AndAlso
                   SendSingleInput(InputKeyUp(kd)) AndAlso
                   SendSingleInput(InputKeyDown(ku)) AndAlso
                   SendSingleInput(InputKeyUp(ku)) AndAlso
                   SendSingleInput(InputKeyUp(18))
        End Function
        Private Function SendSingleInput(ByVal single_input As INPUT) As Boolean
            Return CBool(SendInput(1, single_input, Marshal.SizeOf(single_input)))
            Application.DoEvents()
        End Function
        Private Function InputKeyDown(ByVal wVk As Short) As INPUT
            Dim i As INPUT
            i.type = INPUT_KEYBOARD
            i.u.ki.wVk = wVk
            i.u.ki.dwFlags = KEYEVENTF_KEYDOWN
            Return i
        End Function
        Private Function InputKeyUp(ByVal wVk As Short) As INPUT
            Dim i As INPUT
            i.type = INPUT_KEYBOARD
            i.u.ki.wVk = wVk
            i.u.ki.dwFlags = KEYEVENTF_KEYUP
            Return i
        End Function
        ' From here on, it's not "my" code, but code taken from Pinvoke.net and other places
        <DllImport("user32.dll", SetLastError:=True)> _
        Private Function SendInput(ByVal cInputs As Integer, ByRef pInputs As INPUT, ByVal cbSize As Integer) As Integer
        End Function
        Structure INPUT
            Public type As Integer
            Public u As InputUnion
        End Structure
        Private Const KEYEVENTF_KEYDOWN As Integer = &H0
        Private Const KEYEVENTF_EXTENDEDKEY As Integer = &H1
        Private Const KEYEVENTF_KEYUP As Integer = &H2
        Private Const KEYEVENTF_UNICODE As Integer = &H4
        Private Const KEYEVENTF_SCANCODE As Integer = &H8
        Private Const INPUT_MOUSE As Integer = 0
        Private Const INPUT_KEYBOARD As Integer = 1
        Private Const INPUT_HARDWARE As Integer = 2
        <StructLayout(LayoutKind.Explicit)> _
        Structure InputUnion
            <FieldOffset(0)> Public mi As MOUSEINPUT
            <FieldOffset(0)> Public ki As KEYBDINPUT
            <FieldOffset(0)> Public hi As HARDWAREINPUT
        End Structure
        Structure MOUSEINPUT
            Public dx As Integer
            Public dy As Integer
            Public mouseData As Integer
            Public dwFlags As Integer
            Public time As Integer
            Public dwExtraInfo As IntPtr
        End Structure
        Private Const MOUSEEVENTF_MOVE = &H1
        Private Const MOUSEEVENTF_LEFTDOWN = &H2
        Private Const MOUSEEVENTF_LEFTUP = &H4
        Private Const MOUSEEVENTF_RIGHTDOWN = &H8
        Private Const MOUSEEVENTF_RIGHTUP = &H10
        Private Const MOUSEEVENTF_MIDDLEDOWN = &H20
        Private Const MOUSEEVENTF_MIDDLEUP = &H40
        Private Const MOUSEEVENTF_ABSOLUTE = &H8000
        Structure KEYBDINPUT
            Public wVk As Short
            Public wScan As Short
            Public dwFlags As Integer
            Public time As Integer
            Public dwExtraInfo As IntPtr
        End Structure
        Structure HARDWAREINPUT
            Public uMsg As Integer
            Public wParamL As Short
            Public wParamH As Short
        End Structure
    End Module
End Namespace

Jan 23rd, 2014, 12:49 PM
Edgemeal

Re: SendInput - Function to type ASCII characters - where's the flaw?

Not sure what the solution is but I normally avoid "sendkey" type solutions.
Have you tried using sendmessage to send the text directly to the control instead?
I tried SendMessageW and SetWindowTextUnicode as declared below, seems fine but found many ways to declare this API online.

Quick test using open dialog from notepad in Win7..

Code:

Imports System.Runtime.InteropServices Public Class Form1 Private stringToSend As String = "C:\Hipóteses\Ações de mínima freqüência.doc" Private Const WM_SETTEXT As Integer = &HC <DllImport("user32.dll", EntryPoint:="SendMessageW")> Private Shared Function SendMessageW(hWnd As IntPtr, Msg As UInt32, ByVal wParam As IntPtr, <MarshalAs(UnmanagedType.LPWStr)> lParam As String) As IntPtr End Function ' '<DllImport("user32.dll", EntryPoint:="SendMessageW", CharSet:=CharSet.Unicode)> _ 'Private Shared Function SetWindowTextUnicode(ByVal hWnd As IntPtr, ByVal Msg As Integer, ByVal wParam As IntPtr, ByVal lParam As String) As IntPtr 'End Function <DllImport("user32.dll", CharSet:=CharSet.Auto, EntryPoint:="FindWindow")> _ Private Shared Function FindWindow(ByVal lpClassName As String, ByVal lpWindowName As String) As IntPtr End Function <DllImport("user32.dll", SetLastError:=True, CharSet:=CharSet.Auto)> _ Private Shared Function FindWindowEx(ByVal parentHandle As IntPtr, ByVal childAfter As IntPtr, ByVal lclassName As String, ByVal windowTitle As String) As IntPtr End Function Private Sub Button1_Click(sender As System.Object, e As System.EventArgs) Handles Button1.Click ' NOTE: Tested on Windows 7(US EN) with an "Open" dialog window open from windows Notepad. ' Used MS SPY++ to figure window, control tree, classnames, etc... ' find the Open dialog window. Dim hWndOpenDialog As IntPtr = FindWindow("#32770", "Open") If hWndOpenDialog = IntPtr.Zero Then MessageBox.Show("Open dialog window not found!") Return Else ' open dialog window found, get handle to combo box parent/container Dim hWndComboParent = FindWindowEx(hWndOpenDialog, IntPtr.Zero, "ComboBoxEx32", Nothing) If hWndComboParent <> IntPtr.Zero Then ' get handle to combo Dim hWndComboBox = FindWindowEx(hWndComboParent, IntPtr.Zero, "ComboBox", Nothing) If hWndComboBox <> IntPtr.Zero Then ' get handle to the "edit" control (where file paths are entered) Dim hWndEditBox = FindWindowEx(hWndComboBox, IntPtr.Zero, "Edit", Nothing) If hWndEditBox <> IntPtr.Zero Then ' send our text to edit control SendMessageW(hWndEditBox, WM_SETTEXT, IntPtr.Zero, stringToSend) ' all done. Else MessageBox.Show("Edit box not found!") End If Else MessageBox.Show("Combo not found!") End If Else MessageBox.Show("Combo parent not found!") End If End If End Sub End Class

Re: SendInput - Function to type ASCII characters - where's the flaw?

Lots of Thanks! I'm still developing these interactions and the functions you've mentioned could come in handy, I'll take a closer look on the documentation for each one of them.
In my case, in order to solve quickly my problem, I have mapped all the key combinations that my keyboard can do (yes, long and boring way), and they cover most of the characters one can use for a filename (although not all, which can be a problem).
The issue that remains intriguing me is that all those key combinations work fine, but those relying on numeric keyboard (to simulate strokes equivalent to Alt+000 or Alt+0000) don't produce the expected character (neither any character at all), regardless of the keydown and keyup events be correctly and orderly catched when I test them.
Here's the resulting code, in case you folks would bother to take a look on it:

vb Code:

Namespace WinApi
    Module WinApi
        Public Function TypeString(ByVal text As String) As Boolean
            For Each c In text
                If Not TypeKeySeq(CharToKeys(Asc(c))) Then Return False
            Next
            Return True
        End Function
        Public Function TypeKeySeq(ByVal ParamArray keys() As Integer) As Boolean
            For Each k In keys
                If Not SendSingleInput(InputKey(Short.Parse(k))) Then Return False
            Next
            Return True
        End Function
        Private Function InputKey(ByVal signaled_wVk As Short) As INPUT
            Dim i As INPUT
            i.type = INPUT_KEYBOARD
            i.u.ki.wVk = IIf(signaled_wVk < 0, -signaled_wVk, signaled_wVk)
            i.u.ki.dwFlags = IIf(signaled_wVk < 0, KEYEVENTF_KEYUP, KEYEVENTF_KEYDOWN)
            Return i
        End Function
        Private Function SendSingleInput(ByVal single_input As INPUT) As Boolean
            Return CBool(SendInput(1, single_input, Marshal.SizeOf(single_input)))
            Application.DoEvents()
        End Function
        Private Function CharToKeys(ByVal char_code As Integer) As Integer()
            Select Case char_code
                Case 9, 13, 27, 32, 48 To 57 : Return {char_code, -char_code}
                    '
                Case 33 : Return {16, 49, -49, -16}
                Case 34 : Return {16, 192, -192, -16}
                Case 35 : Return {16, 51, -51, -16}
                Case 36 : Return {16, 52, -52, -16}
                Case 37 : Return {16, 53, -53, -16}
                Case 38 : Return {16, 55, -55, -16}
                Case 39 : Return {192, -192}
                Case 40 : Return {16, 57, -57, -16}
                Case 41 : Return {16, 48, -48, -16}
                Case 42 : Return {16, 56, -56, -16}
                Case 43 : Return {16, 187, -187, -16}
                    '
                Case 44 To 46 : Return {char_code + 144, -(char_code + 144)}
                    '
                Case 47 : Return {193, -193}
                Case 58 : Return {16, 191, -191, -16}
                Case 59 : Return {191, -191}
                Case 60 : Return {16, 188, -188, -16}
                Case 61 : Return {187, -187}
                Case 62 : Return {16, 190, -190, -16}
                Case 63 : Return {16, 193, -193, -16}
                Case 64 : Return {16, 50, -50, -16}
                    '
                Case 65 To 90 : Return {16, char_code, -char_code, -16}
                    '
                Case 91 : Return {221, -221}
                Case 92 : Return {226, -226}
                Case 93 : Return {220, -220}
                Case 94 : Return {16, 222, -222, -16, 32, -32}
                Case 95 : Return {16, 189, -189, -16}
                Case 96 : Return {16, 219, -219, -16, 32, -32}
                    '
                Case 97 To 122 : Return {char_code - 32, -(char_code - 32)}
                    '
                Case 123 : Return {16, 221, -221, -16}
                Case 124 : Return {16, 226, -226, -16}
                Case 125 : Return {16, 220, -220, -16}
                Case 126 : Return {222, -222, 32, -32}
                    '
                Case 162 : Return {17, 18, 53, -53, -18, -17}
                Case 163 : Return {17, 18, 52, -52, -18, -17}
                    '
                Case 167 : Return {17, 18, 187, -187, -18, -17}
                    '
                Case 170 : Return {17, 18, 221, -221, -18, -17}
                    '
                Case 172 : Return {17, 18, 54, -54, -18, -17}
                    '
                Case 176 : Return {17, 18, 193, -193, -18, -17}
                    '
                Case 178 : Return {17, 18, 50, -50, -18, -17}
                Case 179 : Return {17, 18, 51, -51, -18, -17}
                    '
                Case 185 : Return {17, 18, 49, -49, -18, -17}
                Case 186 : Return {17, 18, 220, -220, -18, -17}
                    '
                Case 192 : Return {16, 219, -219, 65, -65, -16}
                Case 193 : Return {219, -219, 16, 65, -65, -16}
                Case 194 : Return {16, 222, -222, 65, -65, -16}
                Case 195 : Return {222, -222, 16, 65, -65, -16}
                Case 196 : Return {16, 54, -54, 65, -65, -16}
                    '
                Case 199 : Return {16, 186, -186, -16}
                Case 200 : Return {16, 219, -219, 69, -69, -16}
                Case 201 : Return {219, -219, 16, 69, -69, -16}
                Case 202 : Return {16, 222, -222, 69, -69, -16}
                Case 203 : Return {16, 54, -54, 69, -69, -16}
                Case 204 : Return {16, 219, -219, 73, -73, -16}
                Case 205 : Return {219, -219, 16, 73, -73, -16}
                Case 206 : Return {16, 222, -222, 73, -73, -16}
                Case 207 : Return {16, 54, -54, 73, -73, -16}
                    '
                Case 209 : Return {222, -222, 16, 78, -78, -16}
                Case 210 : Return {16, 219, -219, 79, -79, -16}
                Case 211 : Return {219, -219, 16, 79, -79, -16}
                Case 212 : Return {16, 222, -222, 79, -79, -16}
                Case 213 : Return {222, -222, 16, 79, -79, -16}
                Case 214 : Return {16, 54, -54, 79, -79, -16}
                    '
                Case 217 : Return {16, 219, -219, 85, -85, -16}
                Case 218 : Return {219, -219, 16, 85, -85, -16}
                Case 219 : Return {16, 222, -222, 85, -85, -16}
                Case 220 : Return {16, 54, -54, 85, -85, -16}
                    '
                Case 224 : Return {16, 219, -219, -16, 65, -65}
                Case 225 : Return {219, -219, 16, -16, 65, -65}
                Case 226 : Return {16, 222, -222, -16, 65, -65}
                Case 227 : Return {222, -222, 16, -16, 65, -65}
                Case 228 : Return {16, 54, -54, -16, 65, -65}
                    '
                Case 231 : Return {186, -186}
                Case 232 : Return {16, 219, -219, -16, 69, -69}
                Case 233 : Return {219, -219, 69, -69}
                Case 234 : Return {16, 222, -222, -16, 69, -69}
                Case 235 : Return {16, 54, -54, -16, 69, -69}
                Case 236 : Return {16, 219, -219, -16, 73, -73}
                Case 237 : Return {219, -219, 73, -73}
                Case 238 : Return {16, 222, -222, -16, 73, -73}
                Case 239 : Return {16, 54, -54, -16, 73, -73}
                    '
                Case 241 : Return {222, -222, 78, -78}
                Case 242 : Return {16, 219, -219, -16, 79, -79}
                Case 243 : Return {219, -219, 79, -79}
                Case 244 : Return {16, 222, -222, -16, 79, -79}
                Case 245 : Return {222, -222, 79, -79}
                Case 246 : Return {16, 54, -54, -16, 79, -79}
                    '
                Case 249 : Return {16, 219, -219, -16, 85, -85}
                Case 250 : Return {219, -219, 85, -85}
                Case 251 : Return {16, 222, -222, -16, 85, -85}
                Case 252 : Return {16, 54, -54, -16, 85, -85}
                    '
                Case Else : Return New Integer() {}
            End Select
        End Function
        <DllImport("user32.dll", SetLastError:=True)> _
        Private Function SendInput(ByVal cInputs As Integer, ByRef pInputs As INPUT, ByVal cbSize As Integer) As Integer
        End Function
    End Module
End Namespace