SendKeys Is Not Working In Windows 10

Question

SendKeys Is Not Working In Windows 10

The Steve Gaines Laptop Band 21

I am creating a program in Visual Studio with C#. I want to send some keystrokes to another application running on my same laptop. I will post the code I am using below. Nothing happens when I click the button. I have proved with break points that it is finding the handle to the window, but even when I run it with no break point the key strokes never appear. I did get it to sort of work when I put in a timer event. If I started the app and then brought Notepad to the foreground then the keystrokes would appear. I may be able to get that to work, If I must. Is there a better way to code this that will work, or is SetForegroundWindpw blocked in Windows 10?

public partial class Form1 : Form  
{  
    [DllImport("User32.dll")]  
    static extern bool SetForegroundWindow(IntPtr point);  

    private void button1_Click(object sender, EventArgs e)  
    {  
        var p = Process.GetProcessesByName("notepad")[0];  
        var pointer = p.Handle;  
        SetForegroundWindow(pointer);  
        SendKeys.Send("This is a test.");  
    }  
}

Shadow_ 0 Reputation points

2025-07-15T09:24:12.5366667+00:00

don't forget using System.Windows.Forms;

Accepted answer

2 additional answers

Your answer

Shadow_ 0 Reputation points

2025-07-15T09:24:12.5366667+00:00

don't forget using System.Windows.Forms;

Answer 1

Castorix31 90,956

The parameter for SetForegroundWindow is a Window handle, not a Process handle.
And SwitchToThisWindow works better (if it is minimized) :

            var p = System.Diagnostics.Process.GetProcessesByName("notepad").FirstOrDefault();  
            var hWnd = p.MainWindowHandle;  
            //SetForegroundWindow(hWnd);  
            SwitchToThisWindow(hWnd, true);  
            SendKeys.Send("This is a test.");

with

    [DllImport("User32.dll", SetLastError = true, CharSet = CharSet.Auto)]  
    public static extern bool SwitchToThisWindow(IntPtr hWnd, bool fAltTab);

The Steve Gaines Laptop Band 21 Reputation points

2022-07-17T16:40:05.857+00:00

Thank you very much. That worked. I'm a skeptic by nature, so I had my doubts, but it worked perfectly as you coded it.
Ray Goudie 1 Reputation point

2022-11-13T00:41:31.8+00:00

Same here. I had the same issue and this code worked perfectly.

Answer 2

Here are two more solutions to send keys or set text of a specific control in another process which you may find useful in some scenarios:

Using UI Automation
Sending WM_SETTEXT message

Using UI Automation

Using UI Automation, you can get the specific automation element of the main window of the process and query its child to find your desired element. Then send data using either of ValuePattern, or SendKeysm or SendMessage.

To learn more about UI Automation, take a look at:

Here is an example to send text to notepad:

var notepad = System.Diagnostics.Process.GetProcessesByName(&#34;notepad&#34;).FirstOrDefault();
if (notepad != null)
{
    var root = AutomationElement.FromHandle(notepad.MainWindowHandle);
    var element = root.FindAll(TreeScope.Subtree, Condition.TrueCondition)
        .Cast&lt;AutomationElement&gt;()
        .Where(x =&gt; x.Current.ClassName == &#34;Edit&#34; &amp;&amp;
            x.Current.AutomationId == &#34;15&#34;).FirstOrDefault();
    if (element != null)
    {
        if (element.TryGetCurrentPattern(ValuePattern.Pattern, out object pattern))
        {
            ((ValuePattern)pattern).SetValue(&#34;This is a test.&#34;);
        }
        else
        {
            element.SetFocus();
            SendKeys.SendWait(&#34;^{HOME}&#34;);   // Move to start of control
            SendKeys.SendWait(&#34;^+{END}&#34;);   // Select everything
            SendKeys.SendWait(&#34;{DEL}&#34;);     // Delete selection
            SendKeys.SendWait(&#34;This is a test.&#34;);
           // OR 
           // SendMessage(element.Current.NativeWindowHandle, WM_SETTEXT, 0, &#34;This is a test.&#34;);
        }
    }
}

Sending WM_SETTEXT message

Using FindWindowEx, you can find the specific control of the main window of the other process, and then set the text using WM_SETTEXT, for exapmle:

[DllImport(&#34;user32.dll&#34;, SetLastError = true)]
static extern IntPtr FindWindowEx(IntPtr hwndParent, IntPtr hwndChildAfter,
    string lpszClass, string lpszWindow);
[DllImport(&#34;User32.dll&#34;)]
static extern int SendMessage(IntPtr hWnd, int uMsg, IntPtr wParam, string lParam);
const int WM_SETTEXT = 0x000C;

private void button1_Click(object sender, EventArgs e)
{
    //Find notepad by its name, or use the instance which you opened yourself
    var notepad = Process.GetProcessesByName(&#34;notepad&#34;).FirstOrDefault();
    if(notepad!=null)
    {
        var edit = FindWindowEx(notepad.MainWindowHandle, IntPtr.Zero, &#34;Edit&#34;, null);
        SendMessage(edit, WM_SETTEXT, IntPtr.Zero, &#34;This is a test.&#34;);
    }
}

Answer 3

Shadow_ 0

Find your .csproj file in your project folder right click and click edit with notepad

<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">

  <PropertyGroup>
    ...
    <TargetFramework>net8.0-windows</TargetFramework>
    ...
    ...
    ....
    <UseWindowsForms>true</UseWindowsForms>
  </PropertyGroup>

  ....
</Project>

<Project Sdk="Microsoft.NET.Sdk.WindowsDesktop">

<TargetFramework>net8.0-windows</TargetFramework>

<UseWindowsForms>true</UseWindowsForms>

Share via

SendKeys Is Not Working In Windows 10

2 additional answers

Your answer