SendMessage with EM_FINDWORDBREAK problem - c#

i try to use SendMessage with EM_FINDWORDBREAK
i have got the position of mouse >> pos
the problem is SendMessage function always return 0
[DllImport("User32.dll", EntryPoint = "SendMessage")]
public static extern int SendMessage(IntPtr hWnd, uint uMsg, int wParam, int lParam);
int star= SendMessage(hHandle, EM_FINDWORDBREAK, (int)WB_RIGHT, pos);

Use this:
[DllImport("User32.dll", EntryPoint = "SendMessage")]
public static extern IntPtr SendMessage(IntPtr hWnd, uint uMsg, IntPtr wParam, IntPtr lParam);
Instead of:
[DllImport("User32.dll", EntryPoint = "SendMessage")]
public static extern int SendMessage(IntPtr hWnd, uint uMsg, int wParam, int lParam);
because the latter only works on 32-bit systems. (Also, the EntryPoint = "SendMessage" portion is redundant.)

Try the import with SetLastError = true and then Marshal.GetLastWin32Error. Also see pinvoke.net if you got the signature right.

Related

get all text written inside a window

I want to get all text of a window.
I prepared below code.But i can only get window captions/titles.
How can i get all text written inside a window ?
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
static extern int GetWindowTextLength(IntPtr hWnd);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
static extern int GetWindowText(IntPtr hWnd, StringBuilder lpString, int nMaxCount);
Process[] processlist = Process.GetProcesses();
foreach (Process process in processlist)
{
if (!String.IsNullOrEmpty(process.MainWindowTitle))
{
IntPtr xero = new IntPtr(0);
var x = FindWindowByCaption(xero, process.MainWindowTitle);
int length = GetWindowTextLength(x);
StringBuilder sb = new StringBuilder(length + 1);
GetWindowText(x, sb, sb.Capacity);
}
}
You need to enumerate all child windows of the top level windows. You can use EnumChildWindows API in order to accomplish that.
Here is the sample code i have written in C# for you
internal class Program
{
public delegate bool EnumWindowsProc(IntPtr hWnd, IntPtr lParam);
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool EnumWindows(EnumWindowsProc lpEnumFunc, IntPtr lParam);
[DllImport("user32.dll")]
[return: MarshalAs(UnmanagedType.Bool)]
static extern bool EnumChildWindows(IntPtr hWndParent, EnumWindowsProc lpEnumFunc, IntPtr lParam);
[DllImport("user32.dll", CharSet = CharSet.Unicode)]
static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr wParam, StringBuilder lParam);
const uint WM_GETTEXT = 0x000D;
static bool EnumAllChilds(IntPtr hWnd, IntPtr lParam)
{
StringBuilder sb = new StringBuilder(2048);
SendMessage(hWnd, WM_GETTEXT, new IntPtr(sb.Capacity), sb);
if (!string.IsNullOrEmpty($"{sb}"))
{
Console.WriteLine($"\t{hWnd:X}\t{sb}");
}
EnumChildWindows(hWnd, EnumAllChilds, lParam);
return true;
}
static bool EnumTopLevel(IntPtr hWnd, IntPtr lParam)
{
StringBuilder sb = new StringBuilder(2048);
SendMessage(hWnd, WM_GETTEXT, new IntPtr(sb.Capacity), sb);
Console.WriteLine($"TopLevel: hWnd: {hWnd:X}\t{(string.IsNullOrEmpty($"{sb}") ? "No Caption" : $"{sb}")}");
// Call for child windows
EnumChildWindows(hWnd, EnumAllChilds, lParam);
return true;
}
static void Main(string[] args)
{
// Call for TopLevel windows
EnumWindows(EnumTopLevel, IntPtr.Zero);
Console.ReadLine();
}
}

Enter data in a text box of windows pop up using C#

I have to enter the file path in a text box of windows popup
I have tried a piece of the code which can return the handle of a window based on its name.
class Program
{
private const int WM_GETTEXT = 13;
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
public static extern IntPtr SendMessage(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam);
[DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)]
private static extern IntPtr FindWindowEx(IntPtr parentHandle, IntPtr childAfter, string lclassName, string windowTitle);
[DllImport("user32.dll")]
static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
static void Main(string[] args)
{
IntPtr Hwnd = FindWindow(null, "Choose File to Upload");
// Alloc memory for the buffer that recieves the text
IntPtr Handle = Marshal.AllocHGlobal(100);
// send WM_GWTTEXT message to the notepad window
int NumText = (int)SendMessage(Hwnd, WM_GETTEXT, (IntPtr)50, Handle);
// copy the characters from the unmanaged memory to a managed string
string Text = Marshal.PtrToStringUni(Handle);
}
my pop looks like:
I need to set data in a text box of the window.

Using SendMessage() to write to Excel in C#

I made before a program where I could open a process of the notepad and while it's opened, be able to write in it from the C# program console. Now I'm trying to do the same but with the excel, I can run the process, I can open it and I can kill it. But when I try to write in it with the SendMessage() method, nothing happens, is there a way I can do this? Or am I missing something? Thanks!
Here's what I tried so far
Declarations
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
static extern bool PostMessage(HandleRef hWnd, uint Msg, IntPtr wParam, IntPtr lParam);
//include SendMessage
[DllImport("user32.dll")]
public static extern int SendMessage(IntPtr hWnd, int uMsg, int wParam, string lParam);
[DllImport("user32.dll")]
public static extern int SendMessage(IntPtr hWnd, int uMsg, int wParam, int lParam);
[DllImport("user32.dll", SetLastError = true)]
public static extern IntPtr FindWindowEx(IntPtr parentHandle, IntPtr childAfter, string className, string windowTitle);
[DllImport("User32.dll")]
static extern int SetForegroundWindow(IntPtr point);
[DllImport("User32.dll", EntryPoint = "SendMessage")]
extern static int SendMessageGetTextLength(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam);
const uint WM_PASTE = 0x302;
const int WM_SETTEXT = 0X000C;
const int WM_GETTEXTLENGTH = 0x000E;
const int EM_SETSEL = 0x00B1;
const int EM_REPLACESEL = 0x00C2;
static void Main(string[] args)
{
//Abre o programa
Process prcss = new Process();
prcss.StartInfo.FileName = "excel.exe";
prcss.Start();
string aux = prcss.StartInfo.FileName;
//Verifica se o processo está a correr
Process[] processlist = Process.GetProcesses();
Code to write in it with the SendMessage().
case "2":
while (true)
{
//Testar com o SendMessage
Console.WriteLine("\nTexto: \n");
string texto = Console.ReadLine();
if (aux.Length == 0)
{
return;
}
if (prcss != null)
{
IntPtr notepadTextbox = FindWindowEx(prcss.MainWindowHandle, IntPtr.Zero, "edit", null);
int length = SendMessageGetTextLength(notepadTextbox, WM_GETTEXTLENGTH, IntPtr.Zero, IntPtr.Zero);
if (!notepadTextbox.Equals(IntPtr.Zero))
{
//sending the message to the textbox
SendMessage(notepadTextbox, WM_SETTEXT, 0, texto);
SendMessage(notepadTextbox, EM_SETSEL, length, length);
SendMessage(notepadTextbox, EM_REPLACESEL, 1, texto + "\n");
}
}
Console.WriteLine("Sair? (S)im / (N)ão");
sair = Console.ReadLine();
if (sair == "s" || sair == "S")
{
IntPtr k = prcss.MainWindowHandle;
SetForegroundWindow(k);
prcss.Kill();
break;
}
}

Simulate "Key Press" on NON Foreground Window

I am currently developing a program that will send a "key press" (the letter A or 0x41 in virtual key codes) to another program (notepad) every X seconds.
The problem is that for it to work I need the other program (notepad) to be in the FOREGROUND, example :
Process[] processes = Process.GetProcessesByName("notepad");
foreach (Process proc in processes) {
SetForegroundWindow(proc.MainWindowHandle);
// Do Whatever
}
Thread.Sleep(1000);
Is there a way to do that WITHOUT notepad having to be in the foreground ?
Like something that could run in the background ?
You could do it via winApi. Try to use SendMessage
According to this link you can do following:
[DllImport("user32.dll")]
public static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
[DllImport("user32.dll")]
public static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);
[DllImport("user32.dll")]
public static extern IntPtr PostMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);
public static void sendKeystroke(ushort k)
{
const uint WM_KEYDOWN = 0x100;
const uint WM_SYSCOMMAND = 0x018;
const uint SC_CLOSE = 0x053;
IntPtr WindowToFind = FindWindow(null, "Untitled1 - Notepad++");
IntPtr result3 = SendMessage(WindowToFind, WM_KEYDOWN, ((IntPtr)k), (IntPtr)0);
//IntPtr result3 = SendMessage(WindowToFind, WM_KEYUP, ((IntPtr)c), (IntPtr)0);
}

notepad character decoding

I am reading text from a notepad opened by my program.and this is my code
const int WM_GETTEXT = 0x000D;
const int WM_GETTEXTLENGTH = 0x000E;
[DllImport("User32.dll", EntryPoint = "SendMessage")]
extern static int SendMessageGetTextLength(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam);
[DllImport("User32.dll", EntryPoint = "SendMessage", CharSet = CharSet.Auto)]
extern static IntPtr SendMessageGetText(IntPtr hWnd, int msg, IntPtr wParam, [Out] StringBuilder lParam);
[DllImport("user32.dll", EntryPoint = "FindWindowEx")]
public static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
public static string GetText(IntPtr hwnd)
{
if (hwnd == IntPtr.Zero)
throw new ArgumentNullException("hwnd");
IntPtr handler = FindWindowEx(hwnd, new IntPtr(0), "Edit", null);
int length = SendMessageGetTextLength(handler, WM_GETTEXTLENGTH, IntPtr.Zero, IntPtr.Zero);
if (length > 0 && length < int.MaxValue)
{
length++;
StringBuilder sb = new StringBuilder(length);
SendMessageGetText(handler, WM_GETTEXT, (IntPtr)sb.Length, sb);
return sb.ToString();
}
return String.Empty;
}
It is getting the text but in a special encoding.
For example, if the text entered is 'hello' it gets '興梀㇨ȿڳㇺ'.
What is the encoding of this text so I can decode it to ASCII?
Your problem is in fact that you are passing sb.Length in the WM_GETTEXT message, when in fact you should be passing sb.Capacity or even just length.
I would do it like this:
if (length > 0 && length < int.MaxValue)
{
StringBuilder sb = new StringBuilder(length+1);
SendMessageGetText(handler, WM_GETTEXT, (IntPtr)length+1, sb);
return sb.ToString();
}
I'd also point out that WM_GETTEXT will not return more than 64k characters to the length < int.MaxValue isn't what you need.
Of course, in the longer run it may be better to use the Unicode throughout so that you can support international text.
I personally would always opt for using the Unicode APIs and use the following p/invoke declarations:
[DllImport("User32.dll", EntryPoint = "SendMessage",
CharSet = CharSet.Unicode, SetLastError = true)]
extern static int SendMessageGetTextLength(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam);
[DllImport("User32.dll", EntryPoint = "SendMessage",
CharSet = CharSet.Unicode, SetLastError = true)]
extern static IntPtr SendMessageGetText(IntPtr hWnd, int msg, IntPtr wParam, StringBuilder lParam);
[DllImport("user32.dll", EntryPoint = "FindWindowEx",
CharSet = CharSet.Unicode, SetLastError = true)]
public static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
Since you're writing in managed code, you may as well use the managed code automation interfaces, which does all the interop for you. Why reinvent the wheel?
using System.Windows.Automation;
public static string GetText(IntPtr hwnd)
{
IntPtr hwndEdit = FindWindowEx(hwnd, IntPtr.Zero, "Edit", null);
return (string)AutomationElement.FromHandle(hwndEdit).
GetCurrentPropertyValue(AutomationElement.NameProperty);
}
You can even make the automation do the FindWindowEx for you:
public static string GetText(IntPtr hwnd)
{
var editElement = AutomationElement.FromHandle(hwnd).
FindFirst(TreeScope.Subtree,
new PropertyCondition(
AutomationElement.ClassNameProperty, "Edit"));
return (string)editElement.GetCurrentPropertyValue(AutomationElement.NameProperty);
}

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