从另一个类访问表单组件 [英] Access form component from another class

问题描述

我希望标题和这个简单的例子说的一切。

I hope that the title and this simple example says everything.

public partial class Form1 : Form
{
    public Form1()
    {
        InitializeComponent();
    }

    public void UpdateLabel(string str)
    {
        label1.Text = str;
       MessageBox.Show("Hello");
    }

    private void buttonIn_Click(object sender, EventArgs e)
    {
        UpdateLabel("inside");
    }

    private void buttonOut_Click(object sender, EventArgs e)
    {
        MyClass Outside = new MyClass();
        Outside.MyMethod();
    }
}

public class MyClass
{
    public void MyMethod()
    {
         Form1 MyForm1 = new Form1();
         MyForm1.UpdateLabel("outside");
    }
}

当我试图从改变的 lable1 的 MyClass的的它什么都不做。但我可以从外部获取到的 UpdateLable 的方法，它说我打招呼，它只是不改变标签。

When I'm trying to change lable1 from MyClass it does nothing. But I can get to the UpdateLable method from outside, it says Hello to me, it just doesn't change the label.

推荐答案

使用一个委托设置您的标签

Use a delegate for setting your label

public class MyClass {
    Action<String> labelSetter;

    public MyClass(Action<String> labelSetter) {
        this.labelSetter = labelSetter;
    }

    public void MyMethod() {
        labelSetter("outside");
    }
}

public void buttonOut_Click(object sender, EventArgs e) {
    var outside = new MyClass(UpdateLabel);
    outside.MyMethod();
}

这篇关于从另一个类访问表单组件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！