this.tabControl_btn_style.AllowDrop = true;
            this.tabControl_btn_style.Controls.Add(this.tabPage_border);
            this.tabControl_btn_style.Controls.Add(this.tabPage_shadow);
            this.tabControl_btn_style.Controls.Add(this.tabPage_label);
            this.tabControl_btn_style.Controls.Add(this.tabPage_img);
            this.tabControl_btn_style.HotTrack = true;
            this.tabControl_btn_style.Location = new System.Drawing.Point(15, 205);
            this.tabControl_btn_style.Multiline = true;
            this.tabControl_btn_style.Name = "tabControl_btn_style";
            this.tabControl_btn_style.Padding = new System.Drawing.Point(0, 0);
            this.tabControl_btn_style.SelectedIndex = 0;
            this.tabControl_btn_style.TabIndex = 146;
            this.tabControl_btn_style.ItemSize = new System.Drawing.Size(0, 1);
            this.tabControl_btn_style.SelectedIndexChanged += new System.EventHandler(this.tabControl_btn_style_SelectedIndexChanged);
            // 
            this.tabControl_btn_style.Size = new System.Drawing.Size(212, 199);
            this.tabControl_btn_style.SizeMode = System.Windows.Forms.TabSizeMode.Fixed;

关键代码

              this.tabControl_btn_style.ItemSize = new System.Drawing.Size(0, 1);
            this.tabControl_btn_style.SizeMode = System.Windows.Forms.TabSizeMode.Fixed;