每次按下C＃循环增量

Question

I googled a few things before posting, but I couldn't find anything like this. Basically, I want to take text from a textbox, save as a variable (say history1) to then be able to call that in the future to display the text. I can do that, but what I'm stuck with is that I want 3 variables (history1, history2 and history3, for example) and each time the button is pressed the string is moved to the next variable.

For example, the button is pressed, the text is saved as variable history1. The text is changed and the button is pressed again, the text from history1 is moved to variable history2, and the new text is saved as history1. This would only need to work for 3 instances though, not infinitely, so when text is stored in history3 and the button is pressed the text is just overwritten.

The way I had thought of approaching this was:

string history1;
string history2;
string history3;

        for (int i = 1; i < 4; i++)
        {
            history1 = txtOutput.Text;
            btnToFile_Click()
            {
                history2=history1;
                btnToFile_Click()
                {
                  history3=history2;
                }

            }
        }

However, this isn't going to work because the btnToFile_Click doesn't take any arguements. Is there an easier way to go about this or just a way to fix the method not taking arguements ?

Thanks in advance!

Answer 1

Make sure that you delcare history1 , history2 , and history3 on the form level (not inside any method).

Then, have the following code inside the handler of the click event of the button:

history3 = history2;
history2 = history1;
history1 = txtOutput.Text;

Answer 2

You don't need to call the btnToFile_Click() method multiple times in your loop, just move the text from end textbox to another in reverse order. Nor do you need a loop because you only have three textboxes.

Why reverse order? So you move the value to the next textbox before it is overwritten by the new value.

So:

history3 = history2;
history2 = history1;
history1 = txtOutput.Text;

Answer 3

您可以尝试保存在字符串数组中并在调用按钮单击事件时在其中移动字符串

Answer 4

btnToFile_Click() is a Click event handler for btnToFile (a button). You're not supposed to call that method yourself, it's called by the UI framework (say WPF or WinForms etc.). By the way, it does receive a parameter, then event source (since you can assign the same event handler to multiple buttons and do something based on which one sent the event)