title: Creating custom pop up keyboard nothing happen when keys are press
body: <p>What I want to happen is that when a textbox is clicked a pop up keyboard will show and whatever i type on the keyboard will be putt in the textbox, but nothing happen but when I use notepad, it works. How can I fix this?</p>
  
  <p>Here is my main form code:</p>
  
  <pre><code>    private void textBox1_MouseClick(object sender, MouseEventArgs e)
      {
          Form1 frm1 = new Form1();
          frm1.ShowDialog();
      }
  </code></pre>
  
  <p>And here is my code for pop up keyboard</p>
  
  <pre><code>public partial class Form1 : Form
  {
      const int WS_EX_NOACTIVATE = 0x08000000;
  //this line of code fixed the issue
  [DllImport("user32.dll", EntryPoint = "GetDesktopWindow")]
          public static extern IntPtr GetDesktopWindow();
  
      public Form1()
      {
          InitializeComponent();
      }
  
      protected override CreateParams CreateParams
      {
          get
          {
              CreateParams param = base.CreateParams;
              param.ExStyle |= WS_EX_NOACTIVATE;
  
  
  //This line of code fix the issues
  param.Style = 0x40000000 | 0x4000000;
                  param.Parent = GetDesktopWindow();
  
              return param;
          }
      }
  
      private void button1_Click(object sender, EventArgs e)
      {
          SendKeys.Send("1");
      }
  
      private void button3_Click(object sender, EventArgs e)
      {
          SendKeys.Send("2");
      }
  
      private void button4_Click(object sender, EventArgs e)
      {
          SendKeys.Send("3");
      }
  
      private void button2_Click(object sender, EventArgs e)
      {
  
      }
  }
  </code></pre>