ViewPager滑動靈敏度調整
ViewPager 手指滑動切換時會不靈敏,我們檢視ViewPager原始碼,切換的判斷是由mFlingDistance和mMinimumVelocity決定的。
private int determineTargetPage(int currentPage, float pageOffset, int velocity, int deltaX) { int targetPage; if (Math.abs(deltaX) > mFlingDistance && Math.abs(velocity) > mMinimumVelocity) { targetPage = velocity > 0 ? currentPage : currentPage + 1; } else { final float truncator = currentPage >= mCurItem ? 0.4f : 0.6f; targetPage = currentPage + (int) (pageOffset + truncator); } ......
而mFlingDistance和mMinimumVelocity是類內部計算的,並沒有公開介面提供設定。
private static final int MIN_DISTANCE_FOR_FLING = 25; // dips private static final int MIN_FLING_VELOCITY = 400; // dips
void initViewPager() { mMinimumVelocity = (int) (MIN_FLING_VELOCITY * density); mFlingDistance = (int) (MIN_DISTANCE_FOR_FLING * density }
我們可以通過反射來調整這2個值,解決滑動靈敏度的問題
val mFlingDistance: Field mFlingDistance = ViewPager::class.java.getDeclaredField("mFlingDistance") mFlingDistance.setAccessible(true) val distance = mFlingDistance.get(mViewPager)//獲取值 mFlingDistance.set(mViewPager, 10) //你定義的值 val mMinimumVelocity: Field mMinimumVelocity = ViewPager::class.java.getDeclaredField("mFlingDistance") mMinimumVelocity.setAccessible(true) val velocity = mMinimumVelocity.get(mViewPager)//獲取值 mMinimumVelocity.set(mViewPager, 5)//你定義的值