如何处理WP8中的文本块

Question

这是我的文本块的代码，

我想显示其中两个数字的差，

但是如果我运行该应用程序，它就会出错。

Error: System.NullReferenceException was unhandled by user code
  HResult=-2147467261
  Message=Object reference not set to an instance of an object.

这是代码，

        TextBlock diffBlock = new TextBlock();


        diffBlock.FontSize = 30;

        diffBlock.Text = " ";

        diffBlock.Text = (total - double.Parse(income.Inc)).ToString();

        ContentPanel.Children.Add(diffBlock);

        Difference.Foreground = new SolidColorBrush(Colors.Black);

        Difference.Text = "Remaining Budget: " + diffBlock;

怎么解决？

Answer 1

您不能使用textbolck作为字符串使用Text属性。 这将解决您的问题。

TextBlock diffBlock = new TextBlock();


        diffBlock.FontSize = 30;

        diffBlock.Text = " ";
      if(income!=null)
        diffBlock.Text = (total - double.Parse(income.Inc)).ToString();
       else
         diffBlock.Text = total.ToString();
         ContentPanel.Children.Add(diffBlock);

        Difference.Foreground = new SolidColorBrush(Colors.Black);

        Difference.Text = "Remaining Budget: " + diffBlock.Text;