Windows Forms中如何限制选手号码输入次数不超过指定圈数？

Hey there! Let's sort out this inconsistent lap count problem you're facing. The main flaw in your current code is using a single global count variable to track input times for all runners—this leads to mixed-up counts since it doesn't track each runner individually. A Dictionary<int, int> is perfect here because it lets us map each runner's number to their current lap count, keeping everything organized.

Step 1: Replace Global Variables with a Dictionary #

First, remove your existing count and invalid variables, and add this dictionary as a member variable in your form class (outside any method):

// Tracks how many times each runner's number has been entered
private Dictionary<int, int> _runnerLapCounts = new Dictionary<int, int>();

Step 2: Rewrite the textBox2_TextChanged Event #

Here's the corrected event code that fixes the count issues and properly enforces the lap limit:

private void textBox2_TextChanged(object sender, EventArgs e)
{
    textBox2.Focus();
    label3.Text = string.Empty; // Clear previous error messages

    bool result = int.TryParse(textBox2.Text, out int runnerNumber);
    // Validate input: must be integer and in the valid runner list
    if (!result || !ReadRunnerNumbers2.Contains(runnerNumber))
    {
        label3.Text = "Please enter a valid player number from the list";
        return;
    }

    // Check if this runner has already reached the max lap count
    if (_runnerLapCounts.TryGetValue(runnerNumber, out int currentCount) && currentCount >= getLaps2)
    {
        MessageBox.Show("Max number of laps for this runner has been entered");
        textBox2.Clear();
        return;
    }

    // Update the lap count for this runner
    if (_runnerLapCounts.ContainsKey(runnerNumber))
    {
        _runnerLapCounts[runnerNumber]++;
    }
    else
    {
        _runnerLapCounts[runnerNumber] = 1;
    }

    // Check if we just hit the max lap count
    if (_runnerLapCounts[runnerNumber] == getLaps2)
    {
        label3.Text = "Max laps for this runner has been entered";
    }

    // Add to the order list and update stats
    RunnerOrder.Add(runnerNumber);
    PlayerNumbersEntered++;
    label8.Text = PlayerNumbersEntered.ToString(); // Fixed: tracks valid input count as intended
    textBox2.Clear();
}

Key Improvements Explained #

• Per-Runner Count Tracking: The _runnerLapCounts dictionary ensures each runner's input count is tracked independently—no more shared count variable confusion.
• Early Validation Checks: We first validate the input, then immediately block any entries for runners who've hit their lap limit, preventing accidental extra inputs.
• Clean State Management: We clear previous error messages at the start to avoid stale text, and properly handle first-time inputs by adding new entries to the dictionary.
• Fixed Stat Display: Updated label8 to show the valid input count instead of the runner number, matching your original comment's intent.

Additional Notes #

• Ensure ReadRunnerNumbers2 (your valid runner list) is properly initialized before this event runs.
• If you need to reset counts for a new race, just call _runnerLapCounts.Clear(); and reset RunnerOrder and PlayerNumbersEntered.

内容的提问来源于stack exchange，提问作者sJay89