将文本框字符串从一种形式发送到另一种形式的列表框

Question

我已经在下面上传了我的代码。我面临的问题是试图将文本从 form2 中的 textBox1 和 textBox2 获取到 form1 中的列表框。当用户打开第二个表单时，他们应该将文本放入文本框并单击按钮 - 它应该关闭 form2 并将文本插入 form1 的 listBox

我尝试了很多事情，但我似乎做不到。我对 c# 编码也很陌生，刚刚开始使用 windows 表单，因此非常感谢任何帮助。

下面的表格 1 代码

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 ToDoList
{
    public partial class Form1 : Form
    {
        List<string> _items = new List<string>();
        public Form1()
        {
            InitializeComponent();
            Form2 form2 = new Form2();
            _items.Add("TITLE\t\t\tDESCRIPTION\t\t\t\t\t\tPRIORITY\tDUE DATE");
            listBox1.DataSource = _items;


        }

        private void filesToolStripMenuItem_Click(object sender, EventArgs e)
        {

        }

        private void openToolStripMenuItem_Click(object sender, EventArgs e)
        {
            Form2 form2 = new Form2();
            form2.Show();
        }

        private void exitToolStripMenuItem_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        public void listView1_SelectedIndexChanged(object sender, EventArgs e)
        {



        }

        public void button2_Click(object sender, EventArgs e)
        {


        }

        public void listBox1_SelectedIndexChanged(object sender, EventArgs e)
        {

        }

        public void listView1_SelectedIndexChanged_1(object sender, EventArgs e)
        {

        }

        private void listBox1_SelectedIndexChanged_1(object sender, EventArgs e)
        {

        }
    }
}

下面的表格 2 代码

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 ToDoList
{
    public partial class Form2 : Form
    {
        List<string> _items = new List<string>();
        public Form2()
        {
            InitializeComponent();
        }

        public void button2_Click(object sender, EventArgs e, string tbtext)
        {
            //Form1 form1 = new Form1();
            //form1.listBox1.Items.Add(tbtext);
            Form1 form1 = new Form1();
            _items.Add(textBox1.Text);
            _items.Add(textBox2.Text);
            _items.Add(comboBox1.Text);

            form1.listBox1.DataSource = null;
            form1.listBox1.DataSource = _items;

        }

        public void button1_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        public void textBox1_TextChanged(object sender, EventArgs e)
        {


        }

        private void button2_Click(object sender, EventArgs e)
        {






            //IF THE USER DOES NOT ENTER items IN THE SPACES THESE IF STATEMENTS BRING A MESSAGEBOX 
            if (string.IsNullOrWhiteSpace(this.textBox2.Text) && string.IsNullOrWhiteSpace(this.textBox1.Text))
            {
                MessageBox.Show("Please Fill The Entries");

            }

            else
            {
                if (string.IsNullOrWhiteSpace(this.textBox1.Text))
                {
                    MessageBox.Show("Please Enter A Task Name");
                }

                if (string.IsNullOrWhiteSpace(this.textBox2.Text))
                {
                    MessageBox.Show("Please Enter A Description");
                }
            }
        }

        public void textBox1_TextChanged_1(object sender, EventArgs e)
        {

        }

        public void textBox2_TextChanged(object sender, EventArgs e)
        {

        }

        public void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
        {

        }
    }
}

Answer 1

你的大体思路是对的，但你必须理解的是Mark在评论中所说的。在 Form2 中创建 Form1 并将数据添加到该表单将不起作用，因为一旦 Form2 关闭，Form1 的实例将不再存在。 IE。您当前正在做的事情看起来像这样的树层次结构：

Form1 (open Form2)
  |
  +-> Form2 (open and save to Form1)
        |
        +-> Form1 (contains saved data but you never see it)

原Form1为父。它负责打开Form2。用ShowDialog，Form1可能知道Form2怎么关闭。因为它是父窗体，所以它可以访问 Form2 上的任何 public 属性。所以说 Form2 有以下 public 字段：

public TextBox textBox1;
public TextBox textBox2;

然后您可以像这样从中检索数据：

public void SomeMethodInForm1()
{
   Form2 form2 = new Form2();

   // Show form2 as a modal dialog and determine if DialogResult = OK. 
   if (form2.ShowDialog(this) == DialogResult.OK)
   {
      // Read the contents of form2's TextBox. 
      this._items.Add(form2.textBox1.Text);
      this._items.Add(form2.textBox2.Text);

      this.listBox1.DataSource = null;
      this.listBox1.DataSource = _items;
   }

   form2.Dispose();
}

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