Button.Click EventHandler问题 [英] Button.Click EventHandler problem

问题描述

大家好.
我正在制作一个小程序，每次按下按钮时都可以添加一个分组框(参见图片) .我的问题是，当我按下组框中的添加"按钮时，我需要使用事件处理程序在文本框中获取文本.

Hello all.
I am making a small program where I can add an groupbox every time a button is pushed ( See picture ). The problem I have is that, when I push the Add button in the groupbox, I need to get the text in the textbox with the eventhandler

private void button1_Click(object sender, EventArgs e)
{
    Button button1 = new Button();
    Label lbText = new Label();

    GroupBox groupBox1 = new GroupBox();
    groupBox1.Text = "Pipe pice number " + pipe;
    groupBox1.Size = new System.Drawing.Size(300, 139);

    button1.Location = new Point(220, 100);
    button1.Text = "Add";
    lbText.Text = "Pipe Size: ";
    lbText.Location = new Point(100, 100);
    lbText.Size = new System.Drawing.Size(90, 13);
    lbText.Visible = true;
    TextBox text = new TextBox();
    text.Location = new Point(100, 100);
    text.Size = new System.Drawing.Size(100, 20);
    // Set the FlatStyle of the GroupBox.
    groupBox1.FlatStyle = FlatStyle.Flat;

    // Add the Button to the GroupBox.
    groupBox1.Controls.Add(button1);

    // Add the textbox to the GroupBox
    groupBox1.Controls.Add(text);

    // Add the label to the Groupbox
    groupBox1.Controls.Add(lbText);

    // Add the GroupBox to the Form.
    flowLayoutPanel1.Controls.Add(groupBox1);
    i += 10;
    pipe += 1;
    label1.Text = Convert.ToString(i);
    button1.Click += new EventHandler(b_Click);
    sender = text.Text;
}

private void b_Click(object sender, EventArgs e)
{
    string btn = ((Button)sender).Name;
    Console.WriteLine(btn);
    textbox1.Text("Display the text from groupbox(X)");
}

这可能吗?

最好的问候，
Morten Starck

Is this possible?

Best Regards,
Morten Starck

推荐答案

如果您正在使用v.3.5，并且已经能够在运行时编写代码安排控件，那么该成长为不再使用无助的new EventHandler(...)的成年状态.

现在，您遇到了将TextBox实例传递给按钮单击处理程序的问题.坦率地说，最好的明显方法是将按钮子类化并添加所需的属性:

If you''re using v.3.5 and already able to write code arranging control during run-time, it''s time to grow up to the adult state who no longer use helpless new EventHandler(...).

Now, you problem to pass the TextBox instance to the handler of button click. Frankly, the best obvious way is to subclass the button and add the required property:

class TextAwareButton : Button {
    protected override void OnClick(EventArgs e) {
        if (TextSource != null || TextHandler != null)
           TextHandler(TextSource.Text); //whatever is that
    }
    public Control TextSource { get; set; }
    public Action<string> TextHandler { get; set; }
} //class TextAwareButton

对于给定的TextAwareButton实例，设置其关联的TextBox或其他Control实例和TextHandler动作，就可以完成.


如果您不想继承子类(例如，懒惰:)，或者代码变得垃圾，您很快就需要)，则可以使用Control.Tag并将所需的数据放入此Tag中；它需要转换回您的类型:

For a given instance of you TextAwareButton, set its associated TextBox or other Control instance and TextHandler action and you''re done.


If you don''t want to subclass (lazy, for example :) , or the code goes to junk, you need it fast), you can use Control.Tag and put data you want in this Tag; it will require casting back to your type:

TextBox text = new TextBox();
Button myButton = new Button();

//...

myButton.Tag = text;
myButton.Click += (sender, eventArgs) {
    Button btn = (Button)sender;
    TextBox text = (TextBox)btn.Tag;
    ProcessText(text.Text);
};

—SA

—SA

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