通过循环数组设置button的id

Question

通过循环设置5个button的id，每次都随机分配。

随机分配没有问题。

在使用两个方法，随机设置button的id以及设置文本的时候出现错误。

弄得很混乱不知道问题出在哪里了？

Button b1, b2, b3, b4, b5;
Button[] buttons = { b1, b2, b3, b4, b5 };

public void shuffleButtons() {

        Integer[] Id = { R.id.bChoice1, R.id.bChoice2, R.id.bChoice3,
                R.id.bChoice4, R.id.bChoice5 };

        ArrayList<Integer> buttonId = new ArrayList<Integer>(Arrays.asList(Id));

        Collections.shuffle(buttonId);


            for (int x = 0; x < 5; x++) {

                for (Button b : buttons) {

                    b = (Button) findViewById(buttonId.get(x));

                }

            }


    }

---

public void setButtonTxt() {


            for (Button b : buttons) {

                for (int x = 0; x <= buttons.length; x++) {

                    b.setText(textList.get(x));

                }
            }

    }

Answer 1

我认为你的循环中x <= buttons.length应该是x < buttons.length,但是你好像要将5个button设置给textList.get(5)

可以用xml预设button：

<Button android:id="@+id/bChoice1" ... />
<!-- etc -->
<Button android:id="@+id/bChoice5" ... />

然后在后面的代码中，随机文本：

Button b1 = (Button)findViewById(R.id.bChoice1);
Button b2 = (Button)findViewById(R.id.bChoice2);
Button b3 = (Button)findViewById(R.id.bChoice3);
Button b4 = (Button)findViewById(R.id.bChoice4);
Button b5 = (Button)findViewById(R.id.bChoice5);

// assuming textList is an ArrayList of text items
// the next two lines will randomize your textList order
// so you don't need to do it yourself and much less
// error-prone
long seed = System.nanoTime();
Collections.shuffle(textList, new Random(seed));

b1.setText(textList.get(0));
b2.setText(textList.get(1));
b3.setText(textList.get(2));
b4.setText(textList.get(3));
b5.setText(textList.get(4));