c# - 我如何制作一个全局数组

Question

我正在尝试使用文件中的数据创建一个全局数组，并将该数组用于不同函数中的计算，例如按钮单击处理程序。当我使用我的计算按钮时，它显示“值不能为空”。

public partial class Form1 : Form
{
    double size = 0;
    double[] temperture;

    public Form1()
    {
        InitializeComponent();
        OpenFileDialog fileDialog = new OpenFileDialog();
        if (fileDialog.ShowDialog() == DialogResult.OK)
        {
            StreamReader sr = new StreamReader(fileDialog.OpenFile());
            string line = sr.ReadLine();
            double size = Convert.ToDouble(line);
            //create array
            double[] temperture = new double[(int)size];
            for (int i = 0; i < size; i++)
            {
                line = sr.ReadLine();
                //convert line to double and store in the array
                temperture[i] = Convert.ToDouble(line);
            }
        }
    }

    private void calculateAverageTempertureToolStripMenuItem1_Click(object sender, System.EventArgs e)
    {
        double sum = temperture.Sum();
        double average = ((double)sum) / temperture.Length;
        textBox1.Text = "Average Temperature = " + average;
    }
}

标签： c#arrayswinforms

Answer 1

不要为 重新声明局部变量temperture：

double[] temperture = new double[(int)size];

重新使用已声明为类实例的实例变量：

temperture = new double[(int)size];