C# 如何从同一个表单中获取数据打开多次，每个表单中都有不同的数据？

Question

我在 MDI 容器中有 Form1，当我提交名称和年龄时，Form2 在同一个容器内打开，名称和年龄写在 2 个标签上，我可以根据需要多次执行此操作。

我的问题是当我单击 Form1 中的保存按钮时，如何从 3 Form2 中获取数据并将其写入 a.txt 文件。

Answer 1

我看到了结合 Form2 字段名称和年龄并存储打开的 Form2 的愚蠢解决方案。 也许是这样：

// Example of Form1
public class Form1 : Form
{ 
    // In this collection we will store all Form2 which would be opened
    List<Form2> openedForms2 = new List<Form2>();
    
    private void ButtonOpenForm2_Click(object sender, EventArgs e)
    {
        string name = nicknameBox.Text;
        string age = ageBox.Text;
    
        // Open Form2 with some values and store it in a List
        Form2 form2 = new Form2(name, age);
        // Subscribe to FormClosed event to be able to remove it from List of opened forms after closing
        form2.FormClosed += (sender, args) => { openedForms2.Remove(form2); };
        form2.Show();
        openedForms2.Add(form2);
    }
    
    private void ButtonSave_Click(object sender, EventArgs e)
    {   
        StringBuilder sb = new StringBuilder(); // Reference to System.Text should be provided
        
        // Here you getting opened forms, which are stored in List
        foreach (Form2 form2 in openedForms2)
        {   
            // And you able to get values of fields Name and Age of each opened form
            string name = form2.Name;
            string age = form2.Age;
            
            // Combine them in a way you wish
            sb.AppendLine("Name: " + name + " | Age: " + age);
        }
        
        // Finally save all combined lines in StringBuilder to some file
        // Don't forget about System.IO reference
        File.WriteAllText("PathToYourFile", sb.ToString());
    }
}


// Example of Form2
public class Form2 : Form
{
    // This fields will be available for access from Form1 after Form2 opened
    private string Name = string.Empty;
    private string Age = string.Empty;
   
    public Form2(string name, string age)
    {  
       // Set fields values
       Name = name;
       Age = age;
        
       // Set labels text
       form2Name.Text = name;
       form2Age.Text = age;
    }
}

Answer 2

我认为您要做的是Winform将 Winform 的文本框值作为 a.txt 文件？

如果是这样，您可以使用System.IO创建TextWriter的实例。 这将采用给定的字符串输入并将其写入您选择的destination.txt 文件，如果该文件尚不存在则创建该文件。

确保在您的 class 顶部有：

using System.IO;

您必须将您的方法放在try/catch块中，因为它在写入时可能会遇到很多错误。 这篇文章告诉你关于获取文本框值

       static void WriteOutput()
        {
    //A using statement uses the object once, then disposes of it's resources after the block
            using (StreamWriter writer = File.CreateText("YOURPATH/YOURFILE.txt"))
            {
                writer.WriteLine(this.textbox1.Text + "\n");
                writer.WriteLine(this.textbox2.Text);
            }
        }