窗体是否处于设计模式阶段

    public partial class TestControl : UserControl
    {
        public TestControl()
        {
            InitializeComponent();

            if (!this.IsDesignMode())
            {
                this.textBox1.Text = "123非设计模式";
            }
            else
            {
                this.textBox1.Text = "456设计模式";
            }
        }

        public bool IsDesignMode()
        {
            bool returnFlag = false;

            #if DEBUG
            if (LicenseManager.UsageMode == LicenseUsageMode.Designtime)
            {
                returnFlag = true;
            }
            else if (System.Diagnostics.Process.GetCurrentProcess().ProcessName == "devenv")
            {
                returnFlag = true;
            }
            #endif
            return returnFlag;
        }
    }