在 C# 中，如何将变量的值而不是变量添加到 mouseclick 事件中？

Question

I decided that I'd try creating a simple programming language. Everything's working so far except for one thing - executing code by clicking on a GUI element. This is the line of code responsible for adding the event to a button:

btn[x].MouseClick += (sender, e) => runAct(act_alloc, sender, e);

The problem here is that the runAct(); void requires an ID (act_alloc) to know what code to run, but act_alloc changes every time a new action for a GUI element is created, but I need the MouseClick event to be a constant number, for example:

btn[0].MouseClick += (sender, e) => runAct(2, sender, e);

I need to get the value of the act_alloc variable at the time of adding the event to the element, but just the value, not the variable itself - I don't want the MouseClick event to use a different ID (the value of act_alloc at the time the element is clicked), I want the MouseClick event to use the same ID every time (the value of act_alloc at the time the element's MouseClick event is assigned to runAct(...) .

The app just reads code from a file line by line. The act_alloc integer gets increased by 1 every time a MouseClick event is added to a GUI element.

The runAct void requires int id, object sender, EventArgs e . The last two are there just so that it can be used as a MouseClick. When some code gets added from the code file to the element's MouseClick event, it gets stored in a String[1024,128] - [Event ID, code (<=127 lines)]. This is the runAct void:

public void runAct(int id, object sender, EventArgs e)
{
    for (int x = 1; x <= Convert.ToInt32(act[id, 0]); x++)
        runCode(act[id, x].Split(';'));
}

act is the String[,] in which code is stored. The first string is always the amount of lines stored, which gets converted into an integer so that it won't just call runCode over and over again without any code to run. The runCode void does what it's called - runs a line of code. One of those can be act;(gui_element); , which means that all following code gets stored in the act string[,]. This stops at a endact; line. After the code is stored in the string[,] ( act[act_alloc, line] ), act_alloc gets increased by 1 so that the app's ready to store some more code in the string[,].

This is the code that adds a MouseClick event to a GUI element:

case "act": //add code to an element
    bool wa = true; //keep looping
    int ln = 1; //line number
    while (wa) //loop for adding more code
    {
        string actstr = vars(sr.ReadLine()); //read the next line
        if (actstr == "endact;") //was that all the code?
        {
            wa = false; //stop the loop
        }
        else
        {
            act[act_alloc, ln] = actstr; //store the line
            ln++; //next line
        }
    }
    ln--; //decrease ln by 1 to make sure runAct runs the correct amount of times
    act[act_alloc, 0] = ln.ToString(); //the amount of lines stored gets saved
    switch (cmd[2]) //what GUI element is this code for?
    {
        case "text": //a label
            for (int x = 0; x < label_alloc; x++) //cycle through all the labels
                if (labels[x].Name == cmd[3]) //does the label name match?
                    labels[x].MouseClick += (sender, e) => runAct(act_alloc, sender, e); //add the event
            break;
            case "btn": //a button
                for (int x = 0; x < btn_alloc; x++) //cycle through all the buttons
                    if (btn[x].Name == cmd[3]) //does the button name match?
                        btn[x].MouseClick += (sender, e) => runAct(act_alloc, sender, e); //add the event
            break;
    }
    act_alloc++; //get ready for storing more code
    break;

If that's still not enough info, please let me know.

Answer 1

How about copying the value of act_alloc right before that line, and then use that local variable in runAct(localvariable, sender, e)? (I'm not certain that your problem is actually there in the first place though)

– lucidbrot

That actually solved my problem, thank you! I just added a new int right before adding the MouseClick event to the element:

act[act_alloc, 0] = ln.ToString();
int eid = act_alloc;
switch (cmd[2])
{
    case "text":
        for (int x = 0; x < label_alloc; x++)
            if (labels[x].Name == cmd[3])
                labels[x].MouseClick += (sender, e) => runAct(eid, sender, e);
        break;
    case "btn":
        for (int x = 0; x < btn_alloc; x++)
            if (btn[x].Name == cmd[3])
                btn[x].MouseClick += (sender, e) => runAct(eid, sender, e);
        break;
}
act_alloc++;