处理中按键的问题

Question

对于示例代码，我用200个随机数字的序列替换了文本：在键盘上上下按压时，条形图会滚动，而屏幕的另一半应该显示每次按下R键时随机选择的200个数字中的一个，或者在按下H键时显示一个“你好”的文本。

在一些帮助下，我能够使我的数字正确地显示在屏幕上，但我不确定如何使这两个不同的按键交互工作，我需要在两者之间周旋：随机数和文本。

我试过这样做，但我似乎不能让它在文本部分起作用：

String numbers[];
String randomnumber;
String h;

//PANNING VARIABLES
float yPan = 0;
boolean panUp = false;
boolean panDown = false;

void setup() {
  fullScreen();
  smooth(2);
  concordance = new IntDict();

  String numberString = "74,34,62,41,81,11,36,76,37,14,54,57,50,57,95,35,82,100,49,67,48,18,11,97,14,41,85,53,80,72,61,91,93,67,72,73,72,20,32,45,62,9,36,70,99,47,6,98,36,26,65,32,75,8,93,71,72,55,95,7,1,36,93,9,21,100,43,22,30,58,21,4,9,4,35,12,57,26,3,90,16,65,36,11,67,4,22,14,63,89,45,10,51,60,3,32,12,41,83,37,100,91,74,76,73,69,6,22,26,100,59,16,24,30,41,77,79,91,86,37,88,26,10,49,32,95,79,50,46,49,45,58,74,22,53,44,82,61,60,61,73,31,41,5,94,38,48,5,90,77,91,6,45,11,1,16,13,23,10,52,45,8,48,16,96,24,61,25,59,40,44,6,13,51,88,42,62,43,94,8,24,47,96,71,10,30,22,68,54,87,70,45,8,78,77,81,24,7,21,7";
  String[] numbers = splitTokens(numberString, ",");

  //FREQUENCY COUNT
  for (int i = 0; i < numbers.length; i++) {
    String s=(numbers[i].toLowerCase());
    concordance.increment(s);
  }
}


void draw() {
  background(0);

  concordance.sortValuesReverse();
  String[] keys = concordance.keyArray();
  for (int i = 0; i < keys.length; i++) {
    String num = keys[i];
    int frequency = concordance.get(num);

    //DRAW GRAPH
    fill(255);
    rect(35, (((i*13)+9)+(yPan)), (frequency*2.2), 6);

    fill(255);
    textAlign(RIGHT);
    textSize(13);
    text(frequency, 30, ((i*13)+16)+(yPan));

    fill(255);
    textAlign(LEFT);
    text(num, (frequency*2.2)+40, ((i*13)+16)+(yPan));
  }
  if (randomnumber!=null) {
    fill(0);
    rect(width/2, 0, width/2, height);

    fill(255);
    textAlign(TOP);
    textSize(60);
    text (randomnumber, width/2+10, 9, width/2, height);
  }

  if (h!=null) {
    fill(0);
    rect(width/2, 0, width/2, height);

    fill(255);
    textAlign(TOP);
    textSize(60);
    text (h, width/2+30, 9, width/2, height);
  }
}

void keyPressed() {

  //SCROLL GRAPH
  if (keyCode == UP) {
    if (panUp) {
      yPan +=35;
    }
    panUp = true;
    panDown = false;
  }

  if (keyCode == DOWN) {
    if (panDown) {
      yPan -=35;
    }
    panUp=false;
    panDown = true;

    //PICK AND SHOW A RANDOM NUMBER WHEN R IS PRESSED
  } else if (key == 'R' || key == 'r') { 
    String numberString = "74,34,62,41,81,11,36,76,37,14,54,57,50,57,95,35,82,100,49,67,48,18,11,97,14,41,85,53,80,72,61,91,93,67,72,73,72,20,32,45,62,9,36,70,99,47,6,98,36,26,65,32,75,8,93,71,72,55,95,7,1,36,93,9,21,100,43,22,30,58,21,4,9,4,35,12,57,26,3,90,16,65,36,11,67,4,22,14,63,89,45,10,51,60,3,32,12,41,83,37,100,91,74,76,73,69,6,22,26,100,59,16,24,30,41,77,79,91,86,37,88,26,10,49,32,95,79,50,46,49,45,58,74,22,53,44,82,61,60,61,73,31,41,5,94,38,48,5,90,77,91,6,45,11,1,16,13,23,10,52,45,8,48,16,96,24,61,25,59,40,44,6,13,51,88,42,62,43,94,8,24,47,96,71,10,30,22,68,54,87,70,45,8,78,77,81,24,7,21,7";
    String[] numbers = splitTokens(numberString, ",");

    int index = int(random(numbers.length));
    randomnumber = numbers[index];

  } else if (key == 'H' || key == 'h') { 
    String h = "hello there";
  }
}

Answer 1

你们很亲密。

首先：

  } else if (key == 'H' || key == 'h') { 
    // String h = "hello there"; -> delete this
    h = "hello there";
  }

之前，当您按下“h”键时，您正在创建一个新的字符串对象h，然后它在任何地方都不能使用。删除h前面的字符串。

  } else if (key == 'R' || key == 'r') { 
    //initialize h string to null
    if (h != null) {
      h = null;  
    }

    String numberString = "74,34...";
    String[] numbers = splitTokens(numberString, ",");

    int index = int(random(numbers.length));
    randomnumber = numbers[index];

  } else if (key == 'H' || key == 'h') { 
    //initialize random number to null
    if (randomnumber != null) {
      randomnumber = null;  
    }

    h = "hello there";
  }