c# - 继承窗体时找不到类型为 ""的构造函数

Question

创建了一个继承自另一个表单的表单，但由于某种原因，我在未找到类型“baseForm”上收到错误构造函数。这是继承类构造函数:

public partial class loadHtmlFormsDatabaseForm :      NEA_Official.createHtmlFormsForm
{
    List<field> listOfFields = new List<field>();
    static string username1;
    int originalListOfFieldsCount;
    htmlFormsProject loadedProject;

    public loadHtmlFormsDatabaseForm(htmlFormsProject loadProject, string username) : base(username1)
    {
        username1 = username;
        loadedProject = loadProject;
        InitializeComponent();
    }

这是基类的构造函数:

    public partial class createHtmlFormsForm : Form
{
    List<field> listOfFields = new List<field>();
    string username = "";

    public createHtmlFormsForm(string username1)
    {
        username = username1;
        InitializeComponent();
    }

Answer 1

你可以通过重载基类中没有参数的构造函数来修复它，如下所示:

public partial class createHtmlFormsForm : Form
{
 List<field> listOfFields = new List<field>();
 string username = "";

 public createHtmlFormsForm(string username1)
 {
    username = username1;
    InitializeComponent();
 }
 public createHtmlFormsForm()
 {
    InitializeComponent();
 }
}

如果您不需要不带参数的构造函数，您可以将其创建为私有(private)的:

public partial class createHtmlFormsForm : Form
{
 List<field> listOfFields = new List<field>();
 string username = "";

 public createHtmlFormsForm(string username1)
 {
    username = username1;
    InitializeComponent();
 }
// private contructor with no parameter
 private createHtmlFormsForm()
 {
    InitializeComponent();
 }
}

或者您可以使用过时的属性:

public partial class createHtmlFormsForm : Form
{
 List<field> listOfFields = new List<field>();
 string username = "";

 public createHtmlFormsForm(string username1)
 {
    username = username1;
    InitializeComponent();
 }

 [Obsolete("Designer only", true)]
 public createHtmlFormsForm()
 {
    InitializeComponent();
 }
}