Question

我有一个包含12个值的数组，我想一个接一个地显示它。最初在应用程序运行时，我显示6个值。在按钮上单击我想逐个显示其他6个值。

prevbutton-> value1 value2 value3 value4 value5 value6 -> nextbutton

所以在下一个按钮上单击它应该是这样的。

prevbutton-> value2 value3 value4 value5 value6 value7 -> nextbutton

这应该持续到12个值，并且在上游按钮的情况下应该反过来。

我使用过这段代码，但它无效：

public void onClick(View v) {
    switch (v.getId()) {
    case R.id.radionextstn:
        forwardtune();
        break;
    }
}

public void forwardtune(){
    Button[] buttons = new Button[5];
    buttons[0] = (Button)findViewById(R.id.radiostation1);
    buttons[1] = (Button)findViewById(R.id.radiostation2);
    buttons[2] = (Button)findViewById(R.id.radiostation3);
    buttons[3] = (Button)findViewById(R.id.radiostation4);
    buttons[4] = (Button)findViewById(R.id.radiostation5);
    buttons[5] = (Button)findViewById(R.id.radiostation6);
    if(currentlyDisplayingFromPosition + 6 >= arraySize)
        return;
    for(int i=0; i<arraySize; i++) {
        buttons[i].setText("");
    }
    for(int i=currentlyDisplayingFromPosition; i<=currentlyDisplayingFromPosition+6; i++){
        if (frequency[i] == 0.0)
            buttons[i].setText("");
        else
            buttons[i].setText("" + frequency[0]);
    }
}

我正在显示前6个值：

public void autoTune() {
    Log.i("autotune", " called");

    if (frequency[0] == 0.0)
        station1.setText(""); // station1 is a button
    else
        station1.setText("" + frequency[0]); // station1 is a button
    if (frequency[1] == 0.0)
        station2.setText(""); // station2 is a button
    else
        station2.setText("" + frequency[1]);  // station2 is a button
    if (frequency[2] == 0.0)
        station3.setText("");  // station3 is a button
    else
        station3.setText("" + frequency[2]); // station3 is a button
    if (frequency[3] == 0.0)
        station4.setText("");   // station4 is a button
    else
        station4.setText("" + frequency[3]);  // station4 is a button
    if (frequency[4] == 0.0)
        station5.setText("");  // station5 is a button
    else
        station5.setText("" + frequency[4]);   // station5 is a button
    if (frequency[5] == 0.0)
        station6.setText("");  // station6 is a button
    else
        station6.setText("" + frequency[5]);  // station6 is a button
}

@Override
protected Boolean doInBackground(Context... params) {
    // TODO Auto-generated method stub
    Log.i("in autotune", " before freq length");
    int[] freq = { 911, 943, 947, 932, 901, 964, 843, 835, 946,904,908,873 };
    freqCounter = 0;
    Log.i("in autotune", "after freq length : " + freq.length);
    frequency = new double[freq.length];
    Log.i("in autotune", "after frequency length : " + frequency.length);
    for (int k = 0; k < freq.length; k++) {
        Log.i("In Radio.java", "Freq : " + freq[k]);
        frequency[k] = freq[k];
        frequency[k] = frequency[k] / 10;
        if (frequency[k] == 0.0)
            break;
        freqCounter++;
        Log.i("In Radio.java", "Frequency : " + frequency[k]);
    }
}

Answer 1

我看到第一个错误，你声明了一个5个按钮的数组并尝试放入6个按钮：

Button[] buttons = new Button[5];

你应该这样做：

Button[] buttons = new Button[6];

Answer 2

解决方案：

if(currentlyDisplayingFromPosition + 6 >= arraySize)
    return;

for(int i=0; i<6; i++){
    buttons[i].setText("" + frequency[currentlyDisplayingFromPosition+i]);
}

Answer 3

根据您的需要进行修改。

Button[] btns = new Button[8];
List<String> pages = new ArrayList<String>();
int mStart = 1;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_dialog_activiy);
    btns[0] = (Button) findViewById(R.id.pr);
    btns[1] = (Button) findViewById(R.id.b1);
    btns[2] = (Button) findViewById(R.id.b2);
    btns[3] = (Button) findViewById(R.id.b3);
    btns[4] = (Button) findViewById(R.id.b4);
    btns[5] = (Button) findViewById(R.id.b5);
    btns[6] = (Button) findViewById(R.id.b6);
    btns[7] = (Button) findViewById(R.id.nt);

    btns[0].setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            rearrangeBy(-1);
        }
    });
    btns[btns.length - 1].setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            rearrangeBy(1);
        }
    });
    // setup listeners
    for (int i = 1; i < btns.length - 1; i++) {
        btns[i].setOnClickListener(mClickListener);
    }
    for (int i = 0; i < 12; i++) {
        pages.add((i + 1) + "");
    }
    setUpButtons();
}

final View.OnClickListener mClickListener = new OnClickListener() {

    @Override
    public void onClick(View v) {
        Toast.makeText(DialogActiviy.this, v.getTag() + "",
                Toast.LENGTH_SHORT).show();

    }
};

private void rearrangeBy(int by) {
    mStart += by;
    setUpButtons();
}

private void setUpButtons() {
    // setup previous button
    btns[0].setEnabled(!(mStart == 1));
    // setup next button
    int end = pages.size() - btns.length + 2 + 1;
    btns[btns.length - 1].setEnabled(!(mStart == end));
    // setup intermediate buttons
    for (int i = 1; i < btns.length - 1; i++) {
        String text = (mStart + i - 1) + "";
        btns[i].setText(text);
        btns[i].setTag(text);
    }
}

向按钮显示值数组

3 个答案: