Question

我目前正在做一项我正在努力的家庭作业。该计划的目标是：

创建一个程序，允许用户记录和查看最多1000个事件的名称。事件的名称将存储在数组中。名称只能按顺序存储和查看：I，e，用户第一次按“Set”存储名称时，它将被放置在数组的索引0中;第二次用户存储名称，它将存储在索引1等中。类似地，当用户第一次按下“查看”时，在用户显示在数组的索引0中找到的项目;第二次用户按下“View”时，会显示在数组的索引1中找到的项目等。

当用户按下“设置”按钮（btnSet）时，如上所述，顺序地将事件名称插入到下一个空闲索引中的数组中。要插入到数组的名称取自txtEventName。
当用户按下“查看”按钮（btnView）时，向用户显示要顺序查看的下一个事件的名称（如上所述）。事件名称以txtName显示给用户。

我目前有代码：

namespace ArrayHW
{
    public partial class Form1 : Form
    {

        int[] eventsArray;
        const int SIZE = 1000;

        public Form1()
        {
            InitializeComponent();
        }

        private void btnSet_Click(object sender, EventArgs e)
        {
            eventsArray = new int[SIZE];

            for (int index = 0; index < eventsArray.Length - 1; index++)
            {
                eventsArray[index] = Convert.ToInt32(txtEventName.Text);
            }

        }

        private void btnView_Click(object sender, EventArgs e)
        {
            for (int index = 0; index < eventsArray.Length- 1; index++)
            {
                Debug.WriteLine(eventsArray[index]);
                txtName.Text = Convert.ToString(eventsArray[index]);
            }

        }
    }
}

当我运行表单时，我只得到index = 0,1,2,3等的结果或者我刚刚输入到数组中的任何内容

private void btnSet_Click(object sender, EventArgs e)
{
    eventsArray = new int[SIZE];

    for (int index = 0; index < eventsArray.Length - 1; index++)
    {
        eventsArray[index] = Convert.ToInt32(txtEventName.Text);
    }

}

而不是像它应该的那样按顺序显示。谁能告诉我一个更好的方法来解决这个问题，或者帮助我找出我做错了什么？非常感谢你。

Answer 1

请阅读代码块中的注释。希望这能帮助您解决问题。

public partial class Form1 : Form
{
    const int SIZE = 1000;
    int[] eventsArray = new int[SIZE];

    //as per your requirement, you would need these 
    //to display and set items at proper index in the array.
    int _setIndex = 0;
    int _viewIndex = 0;

    public Form1()
    {
        InitializeComponent();
    }

    private void btnSet_Click(object sender, EventArgs e)
    {
        //this is where your problem is. Every time the Set btn is clicked,
        //you are creating a new array. Therefore you are only seeing what you added in the 
        //last click. Anything that was added to the array on the prior clicks are lost because
        //you just created a new array with the line below.
        //eventsArray = new int[SIZE];
        //You would need to comment the line above because this is code block is being 
        //executed on every btnSet click. New up this array only once by moving this to global scope.

        //for (int index = 0; index < eventsArray.Length - 1; index++)
        //{
        //    eventsArray[index] = Convert.ToInt32(txtEventName.Text);
        //}

        //Since we have created fields to keep track of _setIndex, all we need to do is:
        if (_setIndex < SIZE)
        {
            eventsArray[_setIndex] = Convert.ToInt32(txtEventName.Text);
            _setIndex++;
        }
    }

    private void btnView_Click(object sender, EventArgs e)
    {
        //this wont be necessary.
        //for (int index = 0; index < eventsArray.Length - 1; index++)
        //{
        //    Debug.WriteLine(eventsArray[index]);
        //    txtName.Text = Convert.ToString(eventsArray[index]);
        //}
        if(eventsArray.Length > _viewIndex)
        {
            txtName.Text = Convert.ToString(eventsArray[_viewIndex]);
            //this is to fulfill the requirement below:
            // Similarly, the first time the user presses “View”, the item found in index 0 
            // of the array is shown to the user; the second time the user presses “View”,
            // the item found in index 1 of the array is shown, etc.
            _viewIndex++;
        }
    }
}

Answer 2

试试这个：

int[] eventsArray = new int[SIZE];
int index = 0;
const int SIZE = 1000;

private void btnSet_Click(object sender, EventArgs e)
{
    eventsArray[index++] = Convert.ToInt32(txtEventName.Text);
}

来自Windows的C＃数组输入表单文本框

2 个答案: