我试图在一个类中创建一个方法，并试图在单击按钮时从另一个类(窗体)调用 [英] I am trying to create a method in one class and trying to call from another class (form) on click of a button

问题描述

这是我的第一堂课:

namespace WindowsFormsApplication2 
{

    public partial class Form1 : Form    
    {
        public Form1()
        {
            InitializeComponent();
            /*_enemy = new Class1(this);
            int y = Class1.MyMethod(0);
            textBox1.Text = Convert.ToString (y);*/
        }
        private Class1 _enemy;

        private void button1_Click(object sender, EventArgs e)
        {
            _enemy = new Class1(this);
            int y = Class1.MyMethod();
            textBox1.Text = Convert.ToString(y);
        }
    }
}

这是我的第二堂课:

namespace WindowsFormsApplication2
{

    public class Class1    
    {    
        public Class1( Form1 form )
        {
            _form1 = form;
        }
        public static int MyMethod()
        {
            int i = 0;
            for (int j = 1; j <= 20; j++)
            {
                i = j;
                //Thread.Sleep(100);
            }
            return i;
        }
    }

    // DON'T initialize this with new Form1();
    private Form1 _form1;
}

程序正常运行，在 TextBox 中，我只得到20个输出.我想要的是每次循环运行时的输出.

The program is running correctly and I am getting only 20 as output in the TextBox. What I want is the output each time the loop runs.

像 1,2,3，......... 20 并停止.

也许像柜台.我也尝试使用 Timer ，但无法做到这一点.

Like a counter maybe. I also tried using Timer but couldn't do that.

@Mong Zhu我已经交叉检查了代码，仍然遇到异常.

@Mong Zhu I have cross checked the code, still getting the exception.

完整的代码供您参考:

Form1.cpp

Form1.cpp

namespace WindowsFormsApplication2
{
    public partial class Form1 : Form
    {
        Class1 MyCounterClass;
        private void Form1_Load(object sender, EventArgs e)
        {
            MyCounterClass = new Class1();
            // register the event. The method on the right hand side 
            // will be called when the event is fired
            MyCounterClass.CountEvent += MyCounterClass_CountEvent;
        }

        private void MyCounterClass_CountEvent(int c)
        {
            if (textBox1.InvokeRequired)
            {
                textBox1.BeginInvoke(new Action(() => textBox1.Text = c.ToString()));
            }
            else
            {
                textBox1.Text = c.ToString();
            }
        }

        public Form1()
        {
            InitializeComponent();
        }
        private Class1 _enemy;

        private void button1_Click(object sender, EventArgs e)
        {
            MyCounterClass.MyCountMethod(300, 0, 10);
        }

    }
}

和class1.cpp

and class1.cpp

namespace WindowsFormsApplication2
{
    public class Class1
    {
        public delegate void Counter(int c); // this delegate allows you to transmit an integer


public event Counter CountEvent;

public Class1()
    {

    }
         public void MyCountMethod(int interval_msec, int start, int end)
         {
             System.Threading.Thread t = new System.Threading.Thread(() =>
             {
                 for (int i = start; i <= end; i++)
                 {
                     // Check whether some other class has registered to the event
                     if (CountEvent != null)
                     {
                         // fire the event to transmit the counting data
                         CountEvent(i);
                         System.Threading.Thread.Sleep(interval_msec);
                     }
                 }
             });
             // start the thread
             t.Start();
         }

    // DON'T initialize this with new Form1();
        private Form1 _form1;
    }
}

推荐答案

如果您希望将某些对象的进度报告回表单，则可以使用 IProgress< T> 界面.在此处和此处，但要将其转换为您的给定代码，它将看起来像这样:

If you are looking to report progress from some object back to your form you can use the IProgress<T> interface instead. It is well explained here and here but to translate it to your given code it would look something like this:

public partial class Form1 : Form
{
    private async void button1_Click(object sender, EventArgs e)
    {
        Progress<int> reporter = new Progress<int>(number =>
        {
            textBox1.Text = number.ToString();
        });
        await Task.Run(() => MyClass1.MyMethod(reporter));
    }
}

public class Class1
{
    public static int MyMethod(IProgress<int> reporter)
    {
        for (int i = 1; i <= 20; ++i)
        {
            reporter.Report(i);
            //Thread.Sleep(100);
        }
        return i;
    }
}

请注意

• Class1 不需要 Form1 的任何知识.
• 由于 Class1.MyMethod 是静态的，因此您不需要它的实例.如果要修改Class1中的字段/属性，则需要一个实例.正确与否完全取决于您.
• IProgress< T> 需要.NET Framework 4.5

• Class1 does not need any knowledge of Form1.
• Since Class1.MyMethod is static you do not require an instance of it. If you want to modify fields/properties in Class1 you need an instance. It's really up to you if this is correct or not.
• IProgress<T> requires .NET Framework 4.5

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