WinForm列表框中存储与访问武器配置值的技术问题

Hey there! Let's fix this issue step by step. The error you're seeing happens because newBeamWeapon is a local variable inside the addBeamWeaponButton_Click method — it only exists within that method's scope, so you can't access it from the selectedBeamWeapons_SelectedIndexChanged event handler.

Luckily, you're already on the right track by storing the full beamWeaponClass object in your listBox2 ( addedBeamWeaponsList ). Here's how to properly retrieve and use that stored data when selecting items:

1. Fix the SelectedIndexChanged Event Handler #

Replace your commented-out code in selectedBeamWeapons_SelectedIndexChanged with this:

private void selectedBeamWeapons_SelectedIndexChanged(object sender, EventArgs e)
{
    // First, make sure an item is actually selected
    if (selectedBeamWeapons.SelectedItem != null)
    {
        // Cast the selected item back to your beamWeaponClass type
        beamWeaponClass selectedWeapon = selectedBeamWeapons.SelectedItem as beamWeaponClass;
        
        // Double-check the cast succeeded (in case something unexpected is in the list)
        if (selectedWeapon != null)
        {
            // Sync the UI controls with the stored values
            beamBonus.Text = selectedWeapon.beamBonusValue;
            beamCost.Text = selectedWeapon.beamCostValue;
            beamRange.Text = selectedWeapon.beamRangeValue;
            beamRecycle.Text = selectedWeapon.beamRecycleValue;
            
            // For Beam Arcs, reverse your calculateArcs() logic here
            // Example: Parse selectedWeapon.beamArcsValue and set your arc input controls to match
        }
    }
}

2. Confirm Your Add Logic is Working #

Your current addBeamWeaponButton_Click method is correctly creating and adding the full beamWeaponClass object to the list — that part is solid! The key detail here is that your listBox2 stores the entire object (not just a display string), so casting the selected item back to beamWeaponClass lets you access all stored configuration values.

3. Optional: Clean Up Naming (Best Practice) #

To make your code more readable and maintainable, follow C# naming conventions:

• Rename beamWeaponClass to BeamWeapon (PascalCase for class names)
• Rename properties like beamBonusValue to BeamBonusValue (PascalCase for public properties)

4. Add Remove Functionality (Bonus) #

Since you have an empty removeBeamWeaponButton_Click method, here's how to implement that:

private void removeBeamWeaponButton_Click(object sender, EventArgs e)
{
    if (selectedBeamWeapons.SelectedItem != null)
    {
        selectedBeamWeapons.Items.Remove(selectedBeamWeapons.SelectedItem);
        // Optional: Clear UI controls after removal
        beamBonus.Text = "";
        beamCost.Text = "";
        beamRange.Text = "";
        beamRecycle.Text = "";
    }
}

内容的提问来源于stack exchange，提问作者Trido