如何优化C#中DataGridView批量文本匹配的多分支if语句？

Great question! That long chain of if-else is definitely a pain to maintain—here's how you can clean this up nicely while making the code more scalable and less error-prone:

Step 1: Extract Reusable Logic & Add Error Handling #

First, pull out the repeated cell value parsing into a helper step, and add checks to avoid crashes if cells are empty or contain non-numeric values (something the original code doesn’t handle).

Step 2: Use a Dictionary for Lookup Instead of if-else #

Replace the rigid if-else chain with a dictionary that maps product names directly to the action of updating the corresponding Global variable. This makes adding new products as simple as adding a new dictionary entry, no more editing the loop logic.

Optimized Code #

private void btnfinalize_Click(object sender, EventArgs e)
{
    // Create a map of product names to their Global variable update actions
    var productUpdateMap = new Dictionary<string, Action<int>>
    {
        { "Manga vol 1-5 ", quantity => Global.Book1 += quantity },
        { "Manga vol 6-15 ", quantity => Global.Book2 += quantity },
        { "Novels 1-199 ", quantity => Global.Book3 += quantity },
        { "Novels 200-400 ", quantity => Global.Book4 += quantity },
        { "Comics series mainstream ", quantity => Global.Book5 += quantity },
        { "Comics series secondary ", quantity => Global.Book6 += quantity },
        { "Text book 1 semester/2 modules ", quantity => Global.Book7 += quantity },
        { "Text book module add-ons ", quantity => Global.Book8 += quantity },
        { "Hardcover ", quantity => Global.Hardcover += quantity }
    };

    // Iterate through each row in POSDGV
    foreach (DataGridViewRow row in POSDGV.Rows)
    {
        // Skip the auto-generated new row (if your DGV allows adding rows)
        if (row.IsNewRow) continue;

        // Get product name with null check
        if (row.Cells[0].Value == null) continue;
        string productName = row.Cells[0].Value.ToString();

        // Parse quantity safely (avoid crashes from bad data)
        if (!int.TryParse(row.Cells[1].Value?.ToString(), out int quantity))
        {
            // Optional: Log an error or show a warning for invalid quantity
            continue;
        }

        // Update the matching Global variable if product exists in our map
        if (productUpdateMap.TryGetValue(productName, out var updateAction))
        {
            updateAction(quantity);
        }
        else
        {
            // Optional: Handle unknown products (log, alert user, etc.)
        }
    }
}

Key Improvements: #

• Less Redundancy: No more repeating parsing and assignment logic across every conditional branch.
• Easier Maintenance: Adding a new product only requires one line in the dictionary—no need to mess with the loop or add more else if blocks.
• Error Resilience: Uses int.TryParse instead of Int32.Parse to avoid crashes from invalid numeric values, and checks for null cell values.
• Clearer Readability: The dictionary makes the product-to-variable mapping explicit at a glance, instead of hiding it in a long conditional chain.

If you want to take this even further:

• Move the productUpdateMap to a class-level variable so it’s initialized only once (instead of every time the button is clicked)
• Store product names in a config file or database instead of hardcoding them, so you can update products without recompiling

内容的提问来源于stack exchange，提问作者Vikil Chandrapati