Develop Reference

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();
}
}

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;
}
}

How can I send a string, that has multiple zeros to CMD?

I have a function in WinForms C# app that sends a string (from a textbox) to an active CMD window, using a button.
Unfortunately, if the textbox contains multiple zeros (0000x000F22000), it returns just one zero: 0x0F220
How can I fix this?
private void but_run_Click(object sender, EventArgs e)
{
uint wparam = 0 << 29 | 0;
int i = 0;
for (i = 0; i < textBox1.Text.Length; i++)
{
//PostMessage(child, WM_KEYDOWN, (IntPtr)Keys.Enter, (IntPtr)wparam);
PostMessage(cmdHwnd, WM_CHAR, (int)textBox1.Text[i], 0);
}
PostMessage(cmdHwnd, WM_KEYDOWN, (IntPtr)Keys.Enter, (IntPtr)wparam);
}

You could try using the lParam to specify repeat key presses. Also, pay attention - PostMessage has lParam as the fourth parameter (wParam is before lParam), you're mixing it up in your code.
Next, don't use (int)someChar. You should use the Encoding classes to get byte values from chars.
Use SendMessage instead of PostMessage. PostMessage is asynchronous and can complicate a lot of stuff for you. You don't need the asynchronicity, so don't use it.
Next, why use WM_CHAR? I'd say WM_SETTEXT would be way more appropriate - you can send the whole text at once. Just be careful about using the native resources (eg. the string). To make this as easy as possible, you can make yourself an overload of the SendMessage method:
const uint WM_SETTEXT = 0x000C;
[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern IntPtr SendMessage(IntPtr hWnd, unit Msg,
IntPtr wParam, string lParam);
You can then simply call:
SendMessage(cmdHwnd, WM_SETTEXT, IntPtr.Zero, textBox1.Text);

I've managed to do it like this:
[DllImport("user32.dll", EntryPoint = "FindWindow", SetLastError = true)]
static extern IntPtr FindWindow(IntPtr ZeroOnly, string lpWindowName);
[return: MarshalAs(UnmanagedType.Bool)]
[DllImport("user32.dll", SetLastError = true)]
static extern bool PostMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);
const int WM_CHAR = 0x0102;
public void sendText(string pText, string pCaption)
{
IntPtr wndHndl = FindWindow(IntPtr.Zero, pCaption);
char[] tmpText = pText.ToCharArray();
foreach (char c in tmpText)
{
System.Threading.Thread.Sleep(50);
PostMessage(wndHndl, WM_CHAR, (IntPtr)c, IntPtr.Zero);
}
}
Where pText is the input string and pCaption is title of the window.

How to handle Message Boxes while using webbrowser in C#?

I'm using this webbrowswer feature of C#. Trying to log in a website through my application. Everything goes fine, except when a wrong ID or password is entered there's little message box (that is set on the webpage itself) which pops up and blocks everything until "Ok" is clicked.
So the question is: Is there any possible way to manage this little window (like reading the text inside of it)? If it is then great!
But if there's no way to do that then is there anyway to simply make this message box go away programatically?

You can "manage" the message box dialog by importing some window functions from user32.dll and getting the messagebox dialog's handle by it's class name and window name. For example to click its OK button:
public class Foo
{
[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
[DllImport("user32.dll", EntryPoint = "FindWindow", SetLastError = true)]
private static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);
private void ClickOKButton()
{
IntPtr hwnd = FindWindow("#32770", "Message from webpage");
hwnd = FindWindowEx(hwnd, IntPtr.Zero, "Button", "OK");
uint message = 0xf5;
SendMessage(hwnd, message, IntPtr.Zero, IntPtr.Zero);
}
}
Some reading material from MSDN.

Copy paste from Sires anwser: https://stackoverflow.com/a/251524/954225
private void InjectAlertBlocker() {
HtmlElement head = webBrowser1.Document.GetElementsByTagName("head")[0];
HtmlElement scriptEl = webBrowser1.Document.CreateElement("script");
IHTMLScriptElement element = (IHTMLScriptElement)scriptEl.DomElement;
string alertBlocker = "window.alert = function () { }";
element.text = alertBlocker;
head.AppendChild(scriptEl);
}

here is refined version of Saeb's answer. Saeb's code was not working for me, I added one more step to activate the button and then clicking on it.
using System;
using System.Runtime.InteropServices;
namespace IE_Automation
{
public class IEPoppupWindowClicker
{
[DllImport("user32.dll", SetLastError = true)]
static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter, string lpszClass, string lpszWindow);
[DllImport("user32.dll", EntryPoint = "FindWindow", SetLastError = true)]
private static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
[DllImport("user32.dll", CharSet = CharSet.Auto)]
static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, int wParam, int lParam);
private const int BM_CLICK = 0xF5;
private const uint WM_ACTIVATE = 0x6;
private const int WA_ACTIVE = 1;
public void ActivateAndClickOkButton()
{
// find dialog window with titlebar text of "Message from webpage"
var hwnd = FindWindow("#32770", "Message from webpage");
if (hwnd != IntPtr.Zero)
{
// find button on dialog window: classname = "Button", text = "OK"
var btn = FindWindowEx(hwnd, IntPtr.Zero, "Button", "OK");
if (btn != IntPtr.Zero)
{
// activate the button on dialog first or it may not acknowledge a click msg on first try
SendMessage(btn, WM_ACTIVATE, WA_ACTIVE, 0);
// send button a click message
SendMessage(btn, BM_CLICK, 0, 0);
}
else
{
//Interaction.MsgBox("button not found!");
}
}
else
{
//Interaction.MsgBox("window not found!");
}
}
}
}

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);
}