在Preference裏動態加載layout

在string.xml裏:

 

<com.android.deskclock.settings.AlarmVolumePreference
            android:key="volume_setting"
            android:layout="@layout/alarm_volume_preference"
            android:title="@string/alarm_volume_title" />

 自定義了Prefernce，加載的默認layout爲alarm_volume_preference.xml

 

 

但是因爲需要適應其它平臺[因爲特殊設備的分辨率的原因]，需要在AlarmVolumePreference裏根據不同情況加載layout.

 

查詢/frameworks/base/core/java/android/preference/Preference.java

    /**
     * Sets the layout resource that is inflated as the {@link View} to be shown
     * for this Preference. In most cases, the default layout is sufficient for
     * custom Preference objects and only the widget layout needs to be changed.
     * <p>
     * This layout should contain a {@link ViewGroup} with ID
     * {@link android.R.id#widget_frame} to be the parent of the specific widget
     * for this Preference. It should similarly contain
     * {@link android.R.id#title} and {@link android.R.id#summary}.
     *
     * @param layoutResId The layout resource ID to be inflated and returned as
     *            a {@link View}.
     * @see #setWidgetLayoutResource(int)
     */
    public void setLayoutResource(@LayoutRes int layoutResId) {
        if (layoutResId != mLayoutResId) {
            // Layout changed
            mRecycleEnabled = false;
        }

        mLayoutResId = layoutResId;
    }

 將新增的layout放置到overlay裏，然後在AlarmVolumePreference的構造方法裏調用setLayoutResource：

public AlarmVolumePreference(Context context, AttributeSet attrs) {
        super(context, attrs);
        if(滿足xx條件) {
            setLayoutResource(R.layout.alarm_volume_preference_xx); //不滿足該條件則加載默認layout.
        }
    }