為什么我的if語句在此for循環中不起作用？

Question

題：

我正在設計一個小型的Android應用程序，當您按下看起來像特定樂器的imageButton時會播放聲音（音符），並且可以在6個imageButtons中最多播放10個音符。 它將音符編號存儲在數組中，並將元素設置為特定編號。 這部分似乎工作正常

該應用程序具有一項功能，可讓您播放最近播放的內容。 由於某種原因，它只會播放前一個音符10次-似乎不了解新的數組值，因此它總是掛在for循環中的第一個if語句上。 我需要它來讀取新的數組值，以便可以播放用戶在給定樂器上演奏的內容。

碼：

public void drum1button(View view) { //This code snippet works as expected
    if (studio.drumCount < 10){
        new Thread(drum.drum1).start();
        drum.drums[studio.drumCount] = 0;
        Toast.makeText(getApplicationContext(),studio.drumCount + " drum.drums[studio.drumCount] = " + drum.drums[studio.drumCount],2).show();

        studio.drumCount++;
    }
    else {
    Toast.makeText(getApplicationContext(),"Record limit reached. Head to the studio!",5).show();
    }
}


public void drum2button(View view) {
if (studio.drumCount < 10){
    new Thread(drum.drum2).start();
    drum.drums[studio.drumCount] = 1;
    Toast.makeText(getApplicationContext(),studio.drumCount + " drum.drums[studio.drumCount] = " + drum.drums[studio.drumCount],2).show();

    studio.drumCount++;

}
else {
Toast.makeText(getApplicationContext(),"Record limit reached. Head to the studio!",5).show();
}
}


public void drum3button(View view) {
    if (studio.drumCount <10 ) {
    new Thread(drum.drum3).start();
    drum.drums[studio.drumCount] = 2;
    Toast.makeText(getApplicationContext(),studio.drumCount + " drum.drums[studio.drumCount] = " + drum.drums[studio.drumCount],2).show();

    studio.drumCount++;
    }
    else {
    Toast.makeText(getApplicationContext(),"Record limit reached. Head to the studio!",5).show();
    }

}

public void drum4button(View view) {
    if (studio.drumCount < 10) {
    new Thread(drum.drum4).start();
    drum.drums[studio.drumCount] = 3;
    Toast.makeText(getApplicationContext(),studio.drumCount + " drum.drums[studio.drumCount] = " + drum.drums[studio.drumCount],2).show();

    studio.drumCount++;
    }
    else {
    Toast.makeText(getApplicationContext(),"Record limit reached. Head to the studio!",5).show();
    }
}

public void drum5button(View view) {
    if (studio.drumCount < 10) {
    new Thread(drum.drum5).start();
    drum.drums[studio.drumCount] = 4;
    Toast.makeText(getApplicationContext(),studio.drumCount + " drum.drums[studio.drumCount] = " + drum.drums[studio.drumCount],2).show();

    studio.drumCount++;
    }

    else {
    Toast.makeText(getApplicationContext(),"Record limit reached. Head to the studio!",5).show();
    }
}

public void drum6button(View view) {
    if (studio.drumCount < 10){
    new Thread(drum.drum6).start();
    drum.drums[studio.drumCount] = 5;
    Toast.makeText(getApplicationContext(),studio.drumCount + " drum.drums[studio.drumCount] = " + drum.drums[studio.drumCount],2).show();

    studio.drumCount++;
    }
    else {
        Toast.makeText(getApplicationContext(),"Record limit reached. Head to the studio!",5).show();

    }
}

---

Runnable drumPlayback = new Runnable() {

    public void run() {
    for (int i = 0; i < 10; i++) { //(was i = 10, typo in formatting when //pasting. Still does not work with i = 0
        //handler.postDelayed(drumPlayback, 5000);

        try {Thread.sleep(1000);} catch(Exception e) {}
         if (drum.drums[i] == 0) { 
          new Thread(drum.drum1).start(); //this is the only one that plays

          }
          if (drum.drums[i] == 1) { 
          new Thread(drum.drum2).start(); 
          } 
         if (drum.drums[i] == 2) { 
          new Thread(drum.drum3).start(); 
          } 
           if (drum.drums[i] == 3) { 
          new Thread(drum.drum4).start(); 
          } 
           if (drum.drums[i] == 4) { 
          new Thread(drum.drum5).start(); 
          } 
           if (drum.drums[i] == 5) {
          new Thread(drum.drum6).start(); 
                    }
                }
            }
    };

Answer 1

循環條件是i < 10但是您使用10初始化i。因此循環將永遠不會開始。