Question

我再一次得到了一个无法完成的阵列！我得到它填充和我输入的信息，但我希望它也给我一个整个quizgrade的平均值。基本上每当我向数组添加一个测验成绩时，我希望它将它们全部加在一起然后给我平均值。我出于好的想法，无法弄清楚这一部分。请有人帮忙吗。所有帮助表示赞赏！感谢

给出一点历史：此代码将人员命名为其编号和等级，将其全部添加到数组中，然后将其显示在列表框中。但是，我需要它来平均我放入阵列的等级，但我尝试过的任何作品都没有。以下是代码，也许有人可能会提供帮助。

public partial class Form1 : Form
{

    public Form1()
    {
        InitializeComponent();
    }
    int[] quizGrade = new int[1];
    string[] studentName = new string[1];
    string[] studentNumber = new string[1];
    int numberOfEntries = 0;

    private void button1_Click(object sender, EventArgs e)
    {
        addToArray();
        txtStudentName.Clear();
        txtStudentNumber.Clear();
        txtQuizGrade.Clear();
        addArrayElementsToListbox();
    }
    public void addArrayElementsToListbox()
    {
        listBox1.Items.Clear();
        listBox1.Items.Add("Student Name \t Student Number \t Quiz Grade");
        for (int i = 0; i < studentName.Length; i++)
        {
            listBox1.Items.Add(studentName[i] + "\t" + studentNumber[i] + "\t\t" + quizGrade[i]);
        }
    }
    public void addToArray()
    {
        if (numberOfEntries == 0)
        {
            quizGrade[0] = Convert.ToInt32(txtQuizGrade.Text);
            studentName[0] = txtStudentName.Text;
            studentNumber[0] = txtStudentNumber.Text;
            numberOfEntries += 1;
        }
        else
        {
            numberOfEntries += 1;
            Array.Resize(ref quizGrade, numberOfEntries);
            Array.Resize(ref studentName, numberOfEntries);
            Array.Resize(ref studentNumber, numberOfEntries);
            quizGrade[numberOfEntries - 1] = Convert.ToInt32(txtQuizGrade.Text);
            studentName[numberOfEntries - 1] = txtStudentName.Text;
            studentNumber[numberOfEntries - 1] = txtStudentNumber.Text;
        }
    }
    public void txtAverage_TextChanged(object sender, EventArgs e)
        {
        }

    private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
        }

    private void ClearButton_Click(object sender, EventArgs e)
        {
            listBox1.Items.Clear();
            txtStudentName.Clear();
            txtStudentNumber.Clear();
            txtQuizGrade.Clear();
            Array.Clear(studentName, 0,studentName.Length);
            Array.Clear(studentNumber, 0,studentNumber.Length);
            Array.Clear(quizGrade, 0,quizGrade.Length);
        }

}

}

Answer 1

您可以使用其中一个Enumerable.Average(TSource)函数。

Answer 2

你可以做一个Foreach循环并将它们全部加在一起然后除以条目数。如下。

int total = 0;

foreach(int a in quizGrade)
{
    total = total + a;
}

然后

除以数组的总数。

total = total / numberOfEntries;

这样的事情。我希望这有帮助！

Answer 3

首先，让我们通过将成绩记录捆绑在一起来摆脱大部分复杂性。

public class StudentQuizGrade {
    public string StudentName {get; set;}
    public string StudentNumber {get; set;}
    public int QuizGrade {get; set;}
}

我们在重复数组大小时删除了“不要重复自己”的错误。这让我们可以编写你已经拥有的内容

public partial class Form1 : Form
{

    public Form1()
    {
        InitializeComponent();
    }
    StudentQuizGrade [] quizGrades = new StudentQuizGrade [0];

    private void button1_Click(object sender, EventArgs e)
    {
        addToArray();
        txtStudentName.Clear();
        txtStudentNumber.Clear();
        txtQuizGrade.Clear();
        addArrayElementsToListbox();
    }
    public void addArrayElementsToListbox()
    {
        listBox1.Items.Clear();
        listBox1.Items.Add("Student Name \t Student Number \t Quiz Grade");
        foreach (StudentQuizGrade quizGrade in quizGrades)
        {
            listBox1.Items.Add(quizGrade.StudentName + "\t" + quizGrade.StudentNumber + "\t\t" + quizGrade.QuizGrade);
        }
    }
    public void addToArray()
    {
        Array.Resize(ref quizGrades, quizGrades.Count + 1);
        quizGrade[quizGrades.Count- 1] = new StudentQuizGrade() {
            QuizGrade = Convert.ToInt32(txtQuizGrade.Text);
            StudentName = txtStudentName.Text;
            StudentNumber = txtStudentNumber.Text;
        }
    }

    public void txtAverage_TextChanged(object sender, EventArgs e)
        {
        }

    private void listBox1_SelectedIndexChanged(object sender, EventArgs e)
        {
        }

    private void ClearButton_Click(object sender, EventArgs e)
        {
            listBox1.Items.Clear();
            txtStudentName.Clear();
            txtStudentNumber.Clear();
            txtQuizGrade.Clear();
            Array.Clear(quizGrades, 0,quizGrades.Length);
        }

}

接下来，我们将清理重复更改阵列时发生的事情。我们将通过在我们更改数组中的内容时添加一个事件来实现此目的。需要通知的事项可以添加到QuizGradesChanged，更改quizGrades的内容应该调用QuizGradesChanged()。我们还将使用新方法clearAddInputs()重构清除添加输入，并删除一些不必要的方法。

public delegate void EventHandler();

public partial class Form1 : Form
{
    public event EventHandler QuizGradesChanged;

    public Form1()
    {
        InitializeComponent();
        QuizGradesChanged += addArrayElementsToListbox;
    }
    StudentQuizGrade [] quizGrades = new StudentQuizGrade [0];

    private void button1_Click(object sender, EventArgs e)
    {
        addToArray();
        clearAddInputs();
    }

    private void clearAddInputs()
    {
        txtStudentName.Clear();
        txtStudentNumber.Clear();
        txtQuizGrade.Clear();
    }

    public void addArrayElementsToListbox()
    {
        listBox1.Items.Clear();
        listBox1.Items.Add("Student Name \t Student Number \t Quiz Grade");
        foreach (StudentQuizGrade quizGrade in quizGrades)
        {
            listBox1.Items.Add(quizGrade.StudentName + "\t" + quizGrade.StudentNumber + "\t\t" + quizGrade.QuizGrade);
        }
    }

    public void addToArray()
    {
        Array.Resize(ref quizGrades, quizGrades.Count + 1);
        quizGrade[quizGrades.Count- 1] = new StudentQuizGrade() {
            QuizGrade = Convert.ToInt32(txtQuizGrade.Text);
            StudentName = txtStudentName.Text;
            StudentNumber = txtStudentNumber.Text;
        }
        QuizGradesChanged();
    }

    private void ClearButton_Click(object sender, EventArgs e)
    {
        clearAddInputs();
        Array.Clear(quizGrades, 0,quizGrades.Length);
        QuizGradesChanged();
    }    
}

最后，我们可以添加测验成绩的平均值。我们将有一个方法recalculateAverage()重新计算平均值，并将其显示在txtAverage控件中。

    public Form1()
    {
        InitializeComponent();
        QuizGradesChanged += addArrayElementsToListbox;
        QuizGradesChanged += recalculateAverage
    }

    public void recalculateAverage() {
        if (quizGrades.Count > 0) {
           txtAverage.Text = quizGrades.Select(x => (decimal) x.QuizGrade).Average().ToString();
        } else {
           txtAverage.Text = "No grades to average";
        }
    }

编辑：数组......呃

中可能存在错误

private void ClearButton_Click(object sender, EventArgs e)
{
    clearAddInputs();
    Array.Clear(quizGrades, 0,quizGrades.Length);
    QuizGradesChanged();
}

我更有信心这是正确的：

private void ClearButton_Click(object sender, EventArgs e)
{
    clearAddInputs();
    quizGrades = new StudentQuizGrade[0];
    QuizGradesChanged();
}

平均数组中的测验等级

3 个答案: