How to make a delay in processing project?

问题

I'm using Java within a Processing project. I'm trying to make a delay that doesn't stop the program, but stops only a given block of code. That "processing" block of code could for example add 1 to a variable, then wait one second and then add 1 again. The problem is that delay() (see reference) stops the whole program and Thread.sleep() doesn't work in a Processing project.

回答1:

You should not use delay() or Thread.sleep() in Processing unless you're already using your own threads. Don't use it on the default Processing thread (so don't use it in any of the Processing functions).

Instead, use the frameCount variable or the millis() function to get the time that your event starts, and then check that against the current time to determine when to stop the event.

Here's an example that shows a circle for 5 seconds whenever the user clicks:

int clickTime = 0;
boolean showCircle = false;

void draw(){
  background(64);
  if(showCircle){
    ellipse(width/2, height/2, width, height);

    if(clickTime + 5*1000 < millis()){
      showCircle = false;
    }
  }
}

void mousePressed(){
  clickTime = millis();
  showCircle = true;
}

Side note: please try to use proper punctuation when you type. Right now your question is just one long run-on sentence, which makes it very hard to read.

来源：https://stackoverflow.com/questions/44570019/how-to-make-a-delay-in-processing-project