Question

我有以下代码：

public Form1()
{
    InitializeComponent();


    string strRadio = Utils.ReadFile(strTemp + @"\rstations.txt");
    string[] aRadio = strRadio.Split(new string[] { "#" }, StringSplitOptions.RemoveEmptyEntries);    
    for (int i = 0; i < aRadio.Length; i += 2)
    {
       listBox.Items.Add(aRadio[i]);
    }

}

private void listBox_SelectedIndexChanged(object sender, EventArgs e)
{
    int index = listBox.SelectedIndex;
    MessageBox.Show(aRadio[(index+1)]);
}

现在错误为The name 'aRadio' does not exist in the current context。哪个来自MessageBox.Show(aRadio[(index+1)]);。我是否需要将aRadio声明为公开或其他内容？如果是这样，将如何做？

Answer 1

您在构造函数中将aRadio声明为局部变量。您需要将其声明为实例变量，并在构造函数中为其赋值：

// TODO: Give this a better name
private readonly string[] aRadio;

// TODO: Give your form a better name too
public Form1()
{
    InitializeComponent();

    // TODO: You might want to reconsider reading files in a GUI constructor, too
    // TODO: Use Path.Combine(strTemp, "rstations.txt" instead of concatenation
    string strRadio = Utils.ReadFile(strTemp + @"\rstations.txt");
    aRadio = strRadio.Split(new string[] { "#" },
                            StringSplitOptions.RemoveEmptyEntries);

    for (int i = 0; i < aRadio.Length; i += 2)
    {
       listBox.Items.Add(aRadio[i]);
    }
}

通过向列表框添加自定义对象（或只是KeyValuePair<string, string>）并通过属性绑定显示部分，我不会感到惊讶。这样你就可以获得所选的项而不是所选的索引......没有必要像这样保留文本/值对。

Answer 2

   private string[] aRadio;

    public Form1() { 
      InitializeComponent();       
      string strRadio = Utils.ReadFile(strTemp + @"\rstations.txt");
      this.aRadio = strRadio.Split(new string[] { "#" }, StringSplitOptions.RemoveEmptyEntries);
      for (int i = 0; i < aRadio.Length; i += 2)
      {
        listBox.Items.Add(aRadio[i]);
      }
    }

    private void listBox_SelectedIndexChanged(object sender, EventArgs e) {
      int index = listBox.SelectedIndex;
      MessageBox.Show(this.aRadio[(index+1)]);
    }

Answer 3

您要访问构造函数form1域中定义的变量，以便您可以执行此操作

//Define the variable as an attribute of class

private string[] strRadio;
public Form1()
{
        InitializeComponent();
        string strRadio = Utils.ReadFile(strTemp + @"\rstations.txt");
        aRadio = strRadio.Split(new string[] { "#" }, StringSplitOptions.RemoveEmptyEntries);

        for (int i = 0; i < aRadio.Length; i += 2)
        {
           listBox.Items.Add(aRadio[i]);
        }

    }

    private void listBox_SelectedIndexChanged(object sender, EventArgs e)
    {
        int index = listBox.SelectedIndex;
        MessageBox.Show(aRadio[(index+1)]);
    }
}

Answer 4

System.StringSplitOptions.RemoveEmptyEntries：以这种方式键入将解决您的问题。

不要问我为什么我知道它是这样运作的。

名称XXXX在当前上下文中不存在

4 个答案: