按钮对象访问

Question

我对我的 C# 技能非常生疏，但基本上我需要关闭我以编程方式创建的按钮以“返回”到主菜单。我无法访问我的按钮，我忘记了什么？这是导致问题的行：ikr1.visible = false;

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace Locker_Rental
{    
public partial class Form1 : Form
{
    public object ikr1 { get; private set; }

    public Form1()
    {
        InitializeComponent();
        button4.Visible = false;
        Button lkr1 = new Button();
    }

    private void button1_Click(object sender, EventArgs e)
    {
        hide_buttons();
        build_LL1_Key_Lockers();
    }

    private void button2_Click(object sender, EventArgs e)
    {
        hide_buttons();
        build_LL1_Combo_Lockers();
    }

    private void button3_Click(object sender, EventArgs e)
    {
        hide_buttons();
        build_L2_Combo_Lockers();
    }

    private void hide_buttons()
    {
        button1.Visible = false;
        button2.Visible = false;
        button3.Visible = false;
    }

    private void show_buttons()
    {
        button1.Visible = true;
        button2.Visible = true;
        button3.Visible = true;
    }

    private void build_LL1_Key_Lockers()
    {
        button4.Visible = true;
        Button lkr1 = new Button();
        lkr1.Location = new Point(25, 25);
        lkr1.Text = "1";
        lkr1.Size = new Size(50, 50);
        lkr1.BackColor = System.Drawing.SystemColors.ButtonFace;
        Controls.Add(lkr1);

    }

    private void build_LL1_Combo_Lockers()
    {
        button4.Visible = true;
    }

    private void build_L2_Combo_Lockers()
    {
        button4.Visible = true;
    }

    private void button4_Click(object sender, EventArgs e)
    {
        button4.Visible = false;
        //turn off ikr1
        **ikr1.visible = false;**

        show_buttons();
    }
}

}

Answer 1

这是因为您引用的是object ikr1，而不是Button（因为它根本不存在！）。该按钮在内部方法中被实例化，因此您无法从 private void button4_Click 方法访问。您需要在此方法之外声明按钮，并在您的事件方法中创建 instance。

试试这个：

namespace Locker_Rental
{    
public partial class Form1 : Form
    {
        public object ikr1 { get; private set; }
        public Button myButton;

        public Form1()
        {
            InitializeComponent();
            button4.Visible = false;
            myButton = new Button();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            hide_buttons();
            build_LL1_Key_Lockers();
        }

        private void button2_Click(object sender, EventArgs e)
        {
            hide_buttons();
            build_LL1_Combo_Lockers();
        }

        private void button3_Click(object sender, EventArgs e)
        {
            hide_buttons();
            build_L2_Combo_Lockers();
        }

        private void hide_buttons()
        {
            button1.Visible = false;
            button2.Visible = false;
            button3.Visible = false;
        }

        private void show_buttons()
        {
            button1.Visible = true;
            button2.Visible = true;
            button3.Visible = true;
        }

        private void build_LL1_Key_Lockers()
        {
            button4.Visible = true;
            myButton = new Button();
            myButton.Location = new Point(25, 25);
            myButton.Text = "1";
            myButton.Size = new Size(50, 50);
            myButton.BackColor = System.Drawing.SystemColors.ButtonFace;
            Controls.Add(myButton);

        }

        private void build_LL1_Combo_Lockers()
        {
            button4.Visible = true;
        }

        private void build_L2_Combo_Lockers()
        {
            button4.Visible = true;
        }

        private void button4_Click(object sender, EventArgs e)
        {
            button4.Visible = false;
            //turn off ikr1
            myButton.Visible = false;

            show_buttons();
        }
    }
}