windows 窗体如何改变风格

//////我看人别人写的一个程序,按一个就变了一种风格
      
        private void 换风格ToolStripMenuItem_Click(object sender, EventArgs e)
        {
            
            this.skinEngine1.ApplyAdditionalBuiltInSkins(0);
            this.skinEngine1.Active = true;
        }
/////////就是这么少在代码,但是我写上一样的还是没用,我没少了什么没写呢?请指教一下!///////系统中自动生成的代码是:            this.skinEngine1.AddtionalBuiltInSkins.Add(this.skinCollectionItem1);
            this.skinEngine1.AddtionalBuiltInSkins.Add(this.skinCollectionItem2);
            this.skinEngine1.AddtionalBuiltInSkins.Add(this.skinCollectionItem3);
            this.skinEngine1.SerialNumber = "";
            this.skinEngine1.SkinFile = null;
            this.skinEngine1.TitleFont = new System.Drawing.Font("宋体", 12F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(134)));
            // 
            // skinCollectionItem1
            // 
            this.skinCollectionItem1.SkinPassword = null;
            this.skinCollectionItem1.SkinSteam = null;
            // 
            // skinCollectionItem2
            // 
            this.skinCollectionItem2.SkinPassword = null;
            this.skinCollectionItem2.SkinSteam = null;
            // 
            // skinCollectionItem3
            // 
            this.skinCollectionItem3.SkinPassword = null;
            this.skinCollectionItem3.SkinSteam = null;