变量未声明或从未分配，并且重建不起作用

Question

I have the same problem that has been asked here and over at the MS forums a lot - I have a combobox control and a string array, so I assign the string array to the combobox in

Form1.Designer.cs

private void InitializeComponent()
{
...
this.ComboBox_Target_0.Items.AddRange(Ranks);
...
}

the array, itself is declared like so:

string[] Ranks = { "Rank 1", "Rank 2", "Rank 3", "Rank 4", "Rank 5", "Rank 6", "Rank 7", "Rank 8", "Rank 9", "Rank 10", "Rank 11", "Rank 12" };

If I build my solution the form runs fine and the combobox has all the items listed and it works fine. However the form designer refuses to start saying "The variable Ranks is either undeclared or was never assigned".

I have seen the other questions about this same problem and have already tried their (only) solution - to rebuild the solution, close VS and open it back up. But that didn't help. I tried putting the string array in "InitializeComponent()" and "public Form1()", rebuilding and etc. each time. However it has not fixed itself for me.

Let me just check - choosing "Ignore and Continue" in this case would not jeopardize anything, right?

Answer 1

I agree that you shouldn't modify the designer file. If there's some reason you need those values available at design time, and you don't want to use the editor, the only way I got it to work without an error is to put this at the very top of the InitializeComponent method:

string[] Ranks = new string[] { "Rank 1", "Rank 2", "Rank 3", "Rank 4", "Rank 5", "Rank 6", "Rank 7", "Rank 8", "Rank 9", "Rank 10", "Rank 11", "Rank 12" };

I added new string[] to the declaration. This is based on how the editor will create the list at design time:

this.ComboBox_Target_0.Items.AddRange(new object[] {...

After defining Ranks like that, your line will work:

this.ComboBox_Target_0.Items.AddRange(Ranks);

If you only need the values at runtime, it's better to do it like this (or a variant thereof):

public partial class Form1 : Form
{
    string[] Ranks = { "Rank 1", "Rank 2", "Rank 3", "Rank 4", "Rank 5", "Rank 6", "Rank 7", "Rank 8", "Rank 9", "Rank 10", "Rank 11", "Rank 12" };

    public Form1()
    {
        InitializeComponent();
        this.ComboBox_Target_0.Items.AddRange(Ranks);
    }
}