将项添加到数组时C＃nullReferenceException

Question

当我尝试将项目添加到数组时，我收到此错误，它会添加1个项目没有问题，但是当有更多项目停止并出错时。

的NullReferenceException 对象引用未设置为对象的实例。

public void btnZoek_Click(object sender, EventArgs e)
{
    if (search == false)
    {
        OpenFiles[index] = new AddFileClass();

        System.IO.DirectoryInfo di = new System.IO.DirectoryInfo(Application.StartupPath + "\\Saves");
        System.IO.FileInfo[] rgFiles = di.GetFiles("*.txt");//add only .txt files

        foreach (System.IO.FileInfo fi in rgFiles)
        {
            OpenFiles[index].setNewItem(index, fi.Name, Convert.ToString(di));//send the info to the array (Number, filename, filelocation)
            index++;
        }
        search = true; //make sure it doens'nt add something double
    }
    if (search == true)
    {
        Form3_Zoeken_ frmSearch = new Form3_Zoeken_();
        frmSearch.Show();
    }
}

这是一张照片，显示fi（FileInfo）和di（DirectoryInfo）不为空：

Answer 1

在我看来，你永远不会初始化OpenFiles数组项 - 也就是说，你只是初始化第一项。

试试这个：

public void btnZoek_Click(object sender, EventArgs e)
{
    if (search == false)
    {
        System.IO.DirectoryInfo di = new System.IO.DirectoryInfo(Application.StartupPath + "\\Saves");
        System.IO.FileInfo[] rgFiles = di.GetFiles("*.txt");//add only .txt files

        foreach (System.IO.FileInfo fi in rgFiles)
        {
            OpenFiles[index] = new AddFileClass();
            OpenFiles[index].setNewItem(index, fi.Name, Convert.ToString(di));//send the info to the array (Number, filename, filelocation)
            index++;
        }
        search = true; //make sure it doens'nt add something double
    }
    if (search == true)
    {
        Form3_Zoeken_ frmSearch = new Form3_Zoeken_();
        frmSearch.Show();
    }
}