C#

List<Note> list = new List<Note>();
                for (int i = 0; i < countFolders; i++)
                {
                    Note AddAllContent = new Note(list) { Category = listFolders[i].IDCategories, Title = listFolders[i].Title, ContentNote = listFolders[i].ContentNote, Image = listFolders[i].Icon };                    
                    list.Add(AddAllContent);
                }
return list;

darkdxd wrote:

C#

String C = TextBox1.Text;
int TXTC = Int32.Parse(C);
string TXTC1 = TXTC.ToString();
TXTC = (TXTF - 32) * (5 / 9); // <-- Error on this line

• C - a local variable of type string;
• TXTC - a local variable of type int;
• TXTC1 - an unused local variable of type string;
• TextBox1 - a field of type TextBox;

• You're using Int32.Parse, which will throw an exception if the user types in something that's not a number. You should use Int32.TryParse[^] instead.
• You convert the integer back to a string for no reason;
• You're performing integer arithmetic, which isn't going to work - for example, 5 / 9 will return 0;
• Based on the variables names, it looks like you've got the calculations the wrong way round;
• You don't do anything with the result of the calculation;

protected void CelsiusTextBox_TextChanged(object sender, EventArgs e)
{
    string celsiusText = CelsiusTextBox.Text;
    
    double celsius;
    if (!double.TryParse(celsiusText, out celsius))
    {
        FahrenheitTextBox.Text = "Please enter a valid temperature";
        return;
    }
    
    double fahrenheit = celsius * (9D / 5D) + 32D;
    FahrenheitTextBox.Text = fahrenheit.ToString();
}

public partial class Weather : System.Web.UI.Page
{
    int TXTC; // will be visible to both event handlers
    int TXTF;

    protected void Page_Load(object sender, EventArgs e)
    {

    }

    protected void TextBox1_TextChanged(object sender, EventArgs e)
    {
        String C = TextBox1.Text;
        TXTC = Int32.Parse(C); // already defined at class level
        string TXTC1 = TXTC.ToString();
        TXTC = (TXTF - 32) * (5 / 9);
    }

    protected void TextBox2_TextChanged(object sender, EventArgs e)
    {
        String F = TextBox2.Text;
        TXTF = Int32.Parse(F);
        string TXTF1 = TXTF.ToString();
        TXTF = (TXTC) * (9 / 5) + 32;
    }
}

private int aClassVariable = 666;
private void foo(int aParameter)
   {
   int aVaraiable = 999;
   if (aParameter > 0)
      {
      int anotherVariable = aParameter / 2;
      }
   }

aClassVariable  is available to all code in the class.
aParameter      is available to all code in the method foo, but not outside it.
aVaraiable      is available to all code in the method foo, but not outside it.
anotherVariable is available to code only within the if block