c# – 将文本框值添加到数组并在列表框中显示.单击按钮时刷新阵

public partial class Form1 : Form        
{

    string[] Brands = new string[10];
    Brands[0] = "Yamaha"; //fail
    Brands[1] = "Suzuki"; //fail
    Brands[2] = "Harley"; //fail
    Brands[3] = "Kawasaki"; //fail

在课堂上下文中.相反,你应该做这样的事情

public partial class Form1 : Form        
{

    string[] Brands = new string[10] { "Yamaha","Suzuki","Harley","Kawasaki","","" };

然后,如果您将Brands声明为Form1类字段,那么在

private void buttonAddbrand_Click(object sender,EventArgs e)
{
    //Brands will be recognized
}

品牌将得到认可.如果你需要做的是向数组添加一些东西(你必须使用数组).那么你还应该保留当前数组中元素的数量,如下所示：

public partial class Form1 : Form        
{

    string[] Brands = new string[10] { "Yamaha","" };
    int brandNo = 4;

然后,当您向数组添加新项目时,请执行以下操作：

private void buttonAddbrand_Click(object sender,EventArgs e)
{
    if(brandNo >= 10)
        return; //cannot add more brand
    Brands[brandNo++] = "NewBrand"; //at the brandNo AFTER you put "NewBrand",see post-increment.
}

编辑：

至于构造函数中的数组初始化,这就是你的老师想要的 – 它实际上是更长的方法.但是为了教学,我只会展示它：

public partial class Form1 : Form        
{
    string[] Brands = new string[10];
    int brandNo; //This is a must
    public Form1(){
        InitializeComponent();
        Brands[0] = "Yamaha"; //ok
        Brands[1] = "Suzuki"; //ok
        Brands[2] = "Harley"; //ok
        Brands[3] = "Kawasaki"; //ok
        brandNo = 4; //This is a must
    }