严谨逻辑处理

严谨逻辑处理很重要，对于不处理或错误的逻辑，要给与判断或列出分支，这样即使不好用，但不至于系统崩溃；否则，不但不好使，很可能系统崩溃

例如下面的严谨逻辑判断代码

示例（1）

private void ShowNavigateBall()       

  {           

  if (Host.Qyxy.Lpbz == "1")            

{    circle.Visibility = Visibility.Visible;         

   dktj.Margin = new Thickness(0, 0, 5, 0);

    smylr.Visibility = Visibility.Visible;                

gxlr.Visibility = Visibility.Visible;                

bglr.Visibility = Visibility.Visible;             

    sjlr.Visibility = Visibility.Visible;            

     smqlr.Visibility = Visibility.Visible;

      sglr.Visibility = Host.Config.AppConfig.ShowSGLR ? Visibility.Visible : Visibility.Collapsed;        

     }          

   else if(Host.Qyxy.Lpbz=="0")//D级时            

{     circle.Visibility = Visibility.Collapsed;      

      dktj.Margin = new Thickness(0, 0, 45, 0);

      smylr.Visibility = Visibility.Visible;      

      gxlr.Visibility = Visibility.Collapsed;          

       bglr.Visibility = Visibility.Collapsed;          

       sjlr.Visibility = Visibility.Collapsed;            

     smqlr.Visibility = Visibility.Collapsed;

       sglr.Visibility = Visibility.Visible;           

  }          

   else     

        {         

        Trace.Write("显示导航球时错误：连盘标识字段值为" + Host.Qyxy.Lpbz);     

        }      

   }

示例（2）

            var count = items.Count();
            //当小于或等于两个元素
            if (count <= 2)
            {
                if (count == 2)
                {
                    var elementLeft = items.ElementAt(0) as FrameworkElement;
                    if (elementLeft != null)
                    {
                        elementLeft.SetValue(Canvas.TopProperty, this.Height / 2 - elementLeft.Height / 2 - 15);
                        elementLeft.SetValue(Canvas.LeftProperty, 0d + 50);
                    }
                    //
                    var elementRight = items.ElementAt(1) as FrameworkElement;
                    if (elementRight != null)
                    {
                        elementRight.SetValue(Canvas.TopProperty, this.Height / 2 - elementRight.Height / 2 - 15);
                        elementRight.SetValue(Canvas.LeftProperty, this.Width - elementRight.Width);
                    }
                }
            }
            else//其它
            {
            }