如何使这种方法可重用？

Question

我已经将此方法复制粘贴到两个类中。 我宁愿从头等课重用它。 这是在Windows窗体应用程序中。

public void defineMapArea()
{
    PictureBox pictureBox1 = new PictureBox();

    // Dock the PictureBox to the form and set its background to white.
    pictureBox1.Dock = DockStyle.Fill;
    pictureBox1.BackColor = Color.White;

    // Connect the Paint event of the PictureBox to the event handler method.
    pictureBox1.Paint += new System.Windows.Forms.PaintEventHandler(this.pictureBox1_Paint);

    // Add the PictureBox control to the Form. 
    this.Controls.Add(pictureBox1);
}

方法上唯一需要从一个类更改为另一个类的是指向该类的“ this”关键字，将鼠标悬停在“ this”上即可确认。 我认为也许“ this”仅适用于调用该方法的类，但是我仍然认为它是指定义该方法的类。将类作为参数简单地传递将是很棒的，但是我在想这是行不通的，因为我已经尝试过了。

任何帮助表示赞赏。 谢谢！

Answer 1

我会这样做：

public static void DefineMapArea(Form form, Action<object, PaintEventArgs> handler)
{
    if (form == null)
    {
        throw new ArgumentNullException("form");
    }

    if (handler == null)
    {
        throw new ArgumentNullException("handler");
    }

    PictureBox pictureBox1 = new PictureBox();

    // Dock the PictureBox to the form and set its background to white.
    pictureBox1.Dock = DockStyle.Fill;
    pictureBox1.BackColor = Color.White;

    // Connect the Paint event of the PictureBox to the event handler method.
    pictureBox1.Paint += new System.Windows.Forms.PaintEventHandler(handler);

    // Add the PictureBox control to the Form. 
    form.Controls.Add(pictureBox1);
}

您可以调用它（假设来自您的表单）：

DefineMapArea(this, (sender, e) =>
{
    // ... put here your code
});

要么

DefineMapArea(this, Handler);

void Handler(object sender, PaintEventArgs e)
{
    // ... put here your code
}

Answer 2

您可以创建一个如下所示的帮助器类：

public static class MapHelper
{
    public static void defineMapArea(this Control parent, PaintEventHandler handler)
    {
        PictureBox pictureBox1 = new PictureBox();

        // Dock the PictureBox to the form and set its background to white.
        pictureBox1.Dock = DockStyle.Fill;
        pictureBox1.BackColor = Color.White;

        // Connect the Paint event of the PictureBox to the event handler method.
        pictureBox1.Paint += handler;

        // Add the PictureBox control to the Form. 
        parent.Controls.Add(pictureBox1);
    }
}

然后这样称呼它：

parentControl.defineMapArea(new PaintEventHandler(this.pictureBox1_Paint));

这是适用于任何控件的扩展方法！ 请注意，您必须将PaintEventHandler作为附加参数传递。

Answer 3

您可以这样写：

class TestClass
{
    internal static void defineMapArea(Form1 form)
    {
        PictureBox pictureBox1 = new PictureBox();

        // Dock the PictureBox to the form and set its background to white.
        pictureBox1.Dock = DockStyle.Fill;
        pictureBox1.BackColor = Color.White;

        // Connect the Paint event of the PictureBox to the event handler method.
        pictureBox1.Paint += new System.Windows.Forms.PaintEventHandler(form.pictureBox1_Paint);

        // Add the PictureBox control to the Form. 
        form.Controls.Add(pictureBox1);
    }
}

并且可以通过这种方式从其他类进行访问：

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

    private void Form1_Load(object sender, EventArgs e)
    {
        TestClass.defineMapArea(this);
    }

    public void pictureBox1_Paint(object sender, EventArgs e)
    {

    }
}

Answer 4

您可以使用表单属性。 在每个表单中添加以下内容：

public Control clsThis {get {return this; }}

那么您可以使用clsThis引用该控件并将其作为参数发送给该方法