如何处理WP8中的文本块

Question

here is the code of my text block,

i want to show the difference of two numbers in it,

but it gives error, whien i run the app.

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

here is the code,

        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;

how to resolve?

Answer 1

You can not use textbolck as a string use Text property. this will resolve your problem.

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;