在按钮单击时切换到动态创建的 TabPage

Question

我正在练习我的编码，并试图通过动态预填充存储在文本文件中的项目来创建一个收银台。我可以根据项目的类别动态创建选项卡、按钮和创建菜单按钮。我正在努力的地方是我试图在单击按钮时切换选项卡。选项卡有一个名称，即类别 ID，文本显示类别。如果尝试切换选项卡，我会收到以下错误：

错误 CS0266 无法将类型“object”隐式转换为“System.Windows.Forms.TabPage”。存在显式转换（您是否缺少演员表？）

我假设我需要创建一个标签页或其他东西，但我不知道如何执行此操作。坚持了几个小时！这是我的代码....

public partial class Form1 : Form
{
    private void Form1_Load(object sender, EventArgs e)
    {
        string[] loadedFile = File.ReadAllLines(@"h:\shopItemsV2.txt");
        foreach (string line in loadedFile)
        {
            // Split string and create required variables
            string[] newBtnData = line.Split(',');
            int catID = int.Parse(newBtnData[0]);
            string cat = newBtnData[1];
            string item = newBtnData[2];
            double price = double.Parse(newBtnData[3]);

            // Create tab if needed
            if (tabControl1.TabCount < catID)
            {
                TabPage tp = new TabPage()
                {
                    Text = cat,
                    Name = catID.ToString()
                };
                tabControl1.TabPages.Add(tp);
                // Add FlowLayoutPanel with unique name
                FlowLayoutPanel fp = new FlowLayoutPanel()
                {
                    Name = "fp" + catID.ToString(),
                    Dock = DockStyle.Fill
                };

                // Add FlowLayoutPanel to correct Tab
                tabControl1.TabPages[catID-1].Controls.Add(fp);

                // Create Button for menu
                Button newMenuBtn = new Button()
                {
                    Name = cat + "Btn",
                    Tag = catID,
                    Width = 100,
                    Height = 50,
                    Text = cat,
                };
                newMenuBtn.Click += SwitchTab;
                menuFP.Controls.Add(newMenuBtn);
            }

            // Create Button
            Button newBtn = new Button()
            {
                Name = item,
                Tag = price,
                Width = 100,
                Height = 100,
                Text = item,
            };
            newBtn.Click += AddItem;

            //Add button to correct tab
            foreach (TabPage tabP in tabControl1.TabPages)
            {

                if (tabP.Name == catID.ToString())
                {
                    Control fp = this.Controls.Find("fp"+catID, true).First();
                    fp.Controls.Add(newBtn);
                }
            }
        }
    }

    private void SwitchTab(object sender, EventArgs e)
    {
        // Create button, switch to required Tab
        // Tabs named the same as Tag on the button
        Button clickedBtn = sender as Button;        
        tabControl1.SelectedTab = clickedBtn.Tag;
    }
}

任何帮助将不胜感激。

Answer 1

您可以在按钮的 Tag() 属性中存储任何内容。考虑到这一点，存储对 TabPage 的引用！

变化：

// Create Button for menu
Button newMenuBtn = new Button()
{
    Name = cat + "Btn",
    Tag = catID,
    Width = 100,
    Height = 50,
    Text = cat,
};

收件人：

// Create Button for menu
Button newMenuBtn = new Button()
{
    Name = cat + "Btn",
    Tag = tp; // store the reference to the TabPage you created
    Width = 100,
    Height = 50,
    Text = cat,
};

那么 Uwe Keim 的建议应该可行：

tabControl1.SelectedTab = clickedBtn.Tag as TabPage;

Answer 2

private void AddNewPr_Click(object sender, EventArgs e)
    {
        TabPage tab = new TabPage();
        _list = new ListBox();
        _list2 = new ListBox();
        PictureBox picBox = new PictureBox();
        picBox.Click = picBox_Click;

        //More stuff here

        //Add the controls        
        tabControl1.Controls.Add(tab);
        tab.Controls.Add(list);
        tab.Controls.Add(list2);
        tab.Controls.Add(pictureBox);
    }