自定义首选项样式填充问题

Question

我正在尝试创建一个 Spinner 首选项，例如在 http://www.hidroh.com/2015/11/30/building-custom-preferences-v7/

到目前为止，我已经像这样扩展了 Preference：

public class SpinnerPreference extends Preference {
    protected String[] mEntries = new String[0];
    protected String[] mEntryValues = new String[0];
    private int mSelection = 0;

    private final LayoutInflater mLayoutInflater;

    public SpinnerPreference(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public SpinnerPreference(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        setWidgetLayoutResource(R.layout.spinner_preference);
        mLayoutInflater = LayoutInflater.from(getContext());
        init(context, attrs);

    }

    private void init(Context context, AttributeSet attrs) {
        TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.SpinnerPreference);
        int entriesResId = ta.getResourceId(R.styleable.SpinnerPreference_entries, 0);
        if (entriesResId != 0) {
            mEntries = context.getResources().getStringArray(entriesResId);
        }
        int valuesResId = ta.getResourceId(R.styleable.SpinnerPreference_entryValues, 0);
        if (valuesResId != 0) {
            mEntryValues = context.getResources().getStringArray(valuesResId);
        }
        ta.recycle();
    }

    @Override
    protected Object onGetDefaultValue(TypedArray a, int index) {
        return a.getString(index);
    }

    @Override
    protected void onSetInitialValue(boolean restorePersistedValue, Object defaultValue) {
        super.onSetInitialValue(restorePersistedValue, defaultValue);
        String value = restorePersistedValue ? getPersistedString(null) : (String) defaultValue;
        for (int i = 0; i < mEntryValues.length; i++) {
            if (TextUtils.equals(mEntryValues[i], value)) {
                mSelection = i;
                break;
            }
        }
    }

    @Override
    public void onBindViewHolder(PreferenceViewHolder holder) {
        super.onBindViewHolder(holder);
        final Spinner spinner = (Spinner) holder.findViewById(R.id.spinner);
        holder.itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                spinner.performClick();
            }
        });
        spinner.setAdapter(new SpinnerAdapter() {
            @Override
            public View getDropDownView(int position, View convertView, ViewGroup parent) {
                if (convertView == null) {
                    convertView = createDropDownView(position, parent);
                }
                bindDropDownView(position, convertView);
                return convertView;
            }

            @Override
            public void registerDataSetObserver(DataSetObserver observer) {
                // no op
            }

            @Override
            public void unregisterDataSetObserver(DataSetObserver observer) {
                // no op
            }

            @Override
            public int getCount() {
                return mEntries.length;
            }

            @Override
            public Object getItem(int position) {
                return null; // not applicable
            }

            @Override
            public long getItemId(int position) {
                return position;
            }

            @Override
            public boolean hasStableIds() {
                return true;
            }

            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                return getDropDownView(position, convertView, parent);
            }

            @Override
            public int getItemViewType(int position) {
                return 0;
            }

            @Override
            public int getViewTypeCount() {
                return 1;
            }

            @Override
            public boolean isEmpty() {
                return false;
            }
        });
        spinner.setSelection(mSelection);
        spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                mSelection = position;
                persistString(mEntryValues[position]);
            }

            @Override
            public void onNothingSelected(AdapterView<?> parent) {
                // no op
            }
        });
    }

    protected View createDropDownView(int position, ViewGroup parent) {
        return mLayoutInflater.inflate(R.layout.spinner_pref_dropdown, parent, false);
    }

    /**
     * Customize dropdown view for given spinner item
     * @param position  item position
     * @param view      item view
     */
    protected void bindDropDownView(int position, View view) {
        TextView textView = (TextView) view.findViewById(android.R.id.text1);
        textView.setText(mEntries[position]);
    }
}

但是这会导致以下结果：

正如您所见，“服务器”标题看起来与其他首选项不同，尽管我没有触及它的风格。填充也非常不同。为什么会发生这种情况？如何修改此样式？

另外，在同一张图片中，你可以看到一个图标，是否可以将此图标与顶部对齐？

偏好 XML：

<android.support.v7.preference.PreferenceScreen
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto">


    <android.support.v7.preference.ListPreference
        android:key="prefs-preferred-quality"
        android:icon="@drawable/ic_soccer"
        android:summary="Bitrate determines the quality of the stream. Auto is recommended."
        android:title="Streaming bitrate"/>


      <android.support.v7.preference.SwitchPreferenceCompat
        android:defaultValue="false"
        android:key="prefs-record-locally"
        android:summary="Should videos also be saved to the device?"
        android:title="Record Locally"/>


    <tv.mycujoo.mycujoobroadcast.settings.preferences.SpinnerPreference
        android:key="prefs-preferred-server"
        android:icon="@drawable/ic_record_dark"
        app:entries="@array/stream_bitrate"
        app:entryValues="@array/stream_bitrate_values"
        android:summary="Streaming region to stream to"
        android:title="Server"/>


</android.support.v7.preference.PreferenceScreen>

编辑：我发布了一个示例代码，只有这个屏幕展示了这两个问题：

https://github.com/kelmer44/prefs-test

Answer 1

我遇到了同样的问题，并在这篇文章中发布了答案：

Custom Preference shows differently on Preference screen than native Preferences

它会解决你的问题。

在您的代码中，只需将代码从 3 参数构造函数移动到 2 参数构造函数（调用 super(context, attrs);）并删除 3 参数构造函数，基类 Preference 将为您选择正确的样式。