安卓SeekBarPreference

Question

我目前正在尝试使用http://android-journey.blogspot.com/2010/01/for-almost-any-application-we-need-to.html教程和RelativeLayout来实现SeekBarPreference类。第一个问题是TextView preferenceText根本没有显示出来。第二个问题是，工具栏不能像常规首选项那样滑动(比如媒体音量栏)？

public class SeekBarPreference extends Preference implements
    OnSeekBarChangeListener {

public static int maximum    = 100;
public static int interval   = 5;
private float oldValue = 25;
private TextView Indicator;

public SeekBarPreference(Context context) {
    super(context);
}

public SeekBarPreference(Context context, AttributeSet attrs) {
    super(context, attrs);
}

public SeekBarPreference(Context context, AttributeSet attrs, int defStyle) {
    super(context, attrs, defStyle);
}

@Override
protected View onCreateView(ViewGroup parent) {

    float scale = getContext().getResources().getDisplayMetrics().density;

    RelativeLayout layout = new RelativeLayout(getContext());

    RelativeLayout.LayoutParams textParams = new RelativeLayout.LayoutParams(
            RelativeLayout.LayoutParams.WRAP_CONTENT,
            RelativeLayout.LayoutParams.WRAP_CONTENT);

    RelativeLayout.LayoutParams sbarParams = new RelativeLayout.LayoutParams(
            Math.round(scale * 160),
            RelativeLayout.LayoutParams.WRAP_CONTENT);

    RelativeLayout.LayoutParams indParams = new RelativeLayout.LayoutParams(
            RelativeLayout.LayoutParams.WRAP_CONTENT,
            RelativeLayout.LayoutParams.WRAP_CONTENT);

    TextView preferenceText = new TextView(getContext());
    preferenceText.setId(0);
    preferenceText.setText(getTitle());
    preferenceText.setTextSize(18);
    preferenceText.setTypeface(Typeface.SANS_SERIF, Typeface.BOLD);


    SeekBar sbar = new SeekBar(getContext());
    sbar.setId(1);
    sbar.setMax(maximum);
    sbar.setProgress((int)this.oldValue);
    sbar.setOnSeekBarChangeListener(this);

    this.Indicator = new TextView(getContext());
    this.Indicator.setTextSize(12);
    this.Indicator.setTypeface(Typeface.MONOSPACE, Typeface.ITALIC);
    this.Indicator.setText("" + sbar.getProgress());

    textParams.addRule(RelativeLayout.ALIGN_PARENT_LEFT);
    sbarParams.addRule(RelativeLayout.RIGHT_OF, preferenceText.getId());
    indParams.setMargins(Math.round(20*scale), 0, 0, 0);
    indParams.addRule(RelativeLayout.RIGHT_OF, sbar.getId());

    preferenceText.setLayoutParams(textParams);
    sbar.setLayoutParams(sbarParams);
    this.Indicator.setLayoutParams(indParams);
    layout.addView(preferenceText);
    layout.addView(this.Indicator);
    layout.addView(sbar);
    layout.setId(android.R.id.widget_frame);

    return layout;
}

@Override
public void onProgressChanged(SeekBar seekBar, int progress,
        boolean fromUser) {
    progress = Math.round(((float) progress)/interval) * interval;

    if(!callChangeListener(progress)) {
        seekBar.setProgress((int) this.oldValue);
        return;
    }

    seekBar.setProgress(progress);
    this.oldValue = progress;
    this.Indicator.setText("" + progress);
    updatePreference(progress);

    notifyChanged();
}

@Override
public void onStartTrackingTouch(SeekBar seekBar) {
}

@Override
public void onStopTrackingTouch(SeekBar seekBar) {
}

@Override
protected Object onGetDefaultValue(TypedArray ta, int index) {
    int dValue = ta.getInt(index, 25);

    return validateValue(dValue);
}

@Override
protected void onSetInitialValue(boolean restoreValue,
        Object defaultValue) {
    int temp = restoreValue ? getPersistedInt(25) : (Integer)defaultValue;
    if(!restoreValue)
        persistInt(temp);

    this.oldValue = temp;
}

private int validateValue(int value) {
    if(value > maximum) 
        value = maximum;
    else if (value < 0)
        value = 0;
    else if (value % interval != 0)
        value = Math.round(((float) value)/interval) * interval;

    return value;
}

private void updatePreference(int newValue) {
    SharedPreferences.Editor editor = getEditor();
    editor.putInt(getKey(), newValue);
    editor.commit();
}

}

Answer 1

这里滑动的问题是由于notifyChange()调用造成的。以某种方式干扰了滑动。我也在开发类似的小部件，因为我不喜欢Dialog方法。

正如我承诺的，下面是我添加到我的开源项目中的解决方案：

我已经编写了一个SeekBarPreference类，它是嵌入在preferences活动中的小部件，而不是弹出对话框。您可以从以下位置下载jar文件：

http://aniqroid.sileria.com/

类的文档和用法在这里：http://aniqroid.sileria.com/doc/api/com/sileria/android/view/SeekBarPreference.html

另外，不要忘记签出方便的伴生类，以便在更改SeekBar：http://aniqroid.sileria.com/doc/api/com/sileria/android/event/PrefsSeekBarListener.html时自动显示摘要

Answer 2

Slider在教程中通过将onProgressChanged更改为

public void onProgressChanged( SeekBar seekBar, int progress, boolean fromUser )
{
    progress = Math.round( ( (float) progress ) / interval ) * interval;
    persistInt(progress);
    callChangeListener( progress );
    seekBar.setProgress( progress );
    this.monitorBox.setText( progress + "" );
    updatePreference( progress );
}

Answer 3

在为它设置了一个合理的宽度，例如400，以及相关的文本视图和一些mod，让它与我的SDK版本编译后，它对我起作用了。与许多其他版本相比，这个版本的一个优势是布局是在代码中完成的，而不是XML，这使得应用程序可以轻松地实例化多个滑块。