使用 SDK 定义的时间参数 Retrieve and cache the system's default animation time or duration

/**
 * The system default "short" animation time duration, in milliseconds. 
 * This duration is ideal for subtle animations or animations that occur very frequently.
 */
private int mShortAnimationDuration = 
    getResources().getInteger(android.R.integer.config_longAnimTime);

sdk/platforms/android-27/data/res/values/config.xml

    <!-- The duration (in milliseconds) of a short animation. -->
    <integer name="config_shortAnimTime">200</integer>

    <!-- The duration (in milliseconds) of a medium-length animation. -->
    <integer name="config_mediumAnimTime">400</integer>

    <!-- The duration (in milliseconds) of a long animation. -->
    <integer name="config_longAnimTime">500</integer>

    <!-- The duration (in milliseconds) of the activity open/close and fragment open/close animations. -->
    <integer name="config_activityShortDur">150</integer>
    <integer name="config_activityDefaultDur">220</integer>

    <!-- The duration (in milliseconds) of the tooltip show/hide animations. -->
    <integer name="config_tooltipAnimTime">150</integer>