C# Winform控件失焦

备忘一下

[DllImport("user32", EntryPoint = "HideCaret")]
//禁止焦点
private static extern bool HideCaret(IntPtr hWnd);

private void richTextBox1_MouseEnter(object sender, EventArgs e)
{
    HideCaret(this.richTextBox1.Handle);
}

private void richTextBox1_MouseDown(object sender, MouseEventArgs e)
{
    HideCaret(this.richTextBox1.Handle);
}