在Fragment里监听RecycerView 滑动事件,来判断向上滑动和向下滑动, 并控制 FolatingActionButton 的隐藏和显示.
FloatingActionButton 在 BaseActivity 中, 后在子Activity 中控制 显示与隐藏, 需要判断 子Activity 中的 ViewPager中的Fragment的滑动监听事件,从而来判断向上还是向下滑动, 然后实现显示隐藏FloatingActionButton;
解决: 通过 接口回调实现判断;
(1).开源地址 : https://github.com/futuresimple/android-floating-action-button
(2).重写FloatingActionButton , 控制其显示与隐藏
package labelnet.cn.ledou.ui;
import android.content.Context;
import android.util.AttributeSet;
import android.view.ViewGroup;
import com.getbase.floatingactionbutton.FloatingActionsMenu;
/**
* FoaltingActionMenu
* 浮动菜单 , 显示和隐藏
* 应用在LebaseActivity 通过代码控制其隐藏和显示
* 显现:mFloatingActionsMenu.show(true);
* 隐藏:mFloatingActionsMenu.show(false);
*/
public class FloatingActionsMenuHidable extends FloatingActionsMenu {
private boolean isShown = true;
private int ANIM_DURATION = 200;
private boolean mVisible = false;
public FloatingActionsMenuHidable(Context context) {
super(context);
}
public FloatingActionsMenuHidable(Context context, AttributeSet attrs) {
super(context, attrs);
}
public FloatingActionsMenuHidable(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
public void show(boolean isVisible) {
mVisible = isVisible;
int translationX = isVisible ? 0 : (getWidth()/2) + getMarginRight();
this.animate().translationX(translationX).setDuration(ANIM_DURATION).start();
}
public boolean isShown() {
return isShown;
}
private int getMarginRight() {
int marginBottom = 0;
final ViewGroup.LayoutParams layoutParams = getLayoutParams();
if (layoutParams instanceof ViewGroup.MarginLayoutParams) {
marginBottom = ((MarginLayoutParams) layoutParams).rightMargin;
}
return marginBottom;
}
public boolean getVisible(){
return mVisible;
}
}
(3). 一个方法实现 ,返回FloatingActionButton 对象 :
FloatingActionsMenuHidable multiple_actions_up = (FloatingActionsMenuHidable) findViewById(R.id.multiple_actions_up);
public FloatingActionsMenuHidable getFloatingActionsMenu() {
return multiple_actions_up;
}
(1) 在Fragment中实现 回调:
public interface TestScrollState {
//滑动的状态 true 为 向上滑动,false 向下滑动
public void upAndDownState(boolean b);
}
经过测试 , 只需要实现 OnScroll 事件就行了, 当dy 为 负值的时候,向下滑动,为正值的时候 ,向上滑动;
不需要实现OnScrollStateChanged , 这里实现测试用的;
/**
* RecyclerView滑动事件
*/
private class ScrollListListener extends RecyclerView.OnScrollListener {
@Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
switch (newState) {
case RecyclerView.SCROLL_STATE_SETTLING:
//到顶端或低端,不能滑动
Log.i("Ledou", "11111111111111111111");
break;
case RecyclerView.SCROLL_STATE_DRAGGING:
//正在滑动
Log.i("Ledou", "22222222222222222222");
break;
case RecyclerView.SCROLL_STATE_IDLE:
//停止滑动
Log.i("Ledou", "3333333333333333");
break;
}
}
@Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
/**
* 向下滑动 dy为负数 false
* 向上滑动 dy为正数 true
*/
if (dy > 0) {
TScrollState.upAndDownState(true);
}else{
TScrollState.upAndDownState(false);
}
}
}
package labelnet.cn.ledou.fragment;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.github.florent37.materialviewpager.MaterialViewPagerHelper;
import com.github.florent37.materialviewpager.adapter.RecyclerViewMaterialAdapter;
import java.util.ArrayList;
import java.util.List;
import labelnet.cn.ledou.R;
import labelnet.cn.ledou.adpater.WeiRecyclerViewAdapter;
/**
* 内容页实现
* 集成自开源项目 : MaterialViewPager
*/
public class RecyclerViewFragment extends Fragment {
private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private static final int ITEM_COUNT = 100;
private List
private RecyclerViewFragment.TestScrollState testScrollState;
public WeiViewPagerAdapter(FragmentManager fm,RecyclerViewFragment.TestScrollState testScrollState) {
super(fm);
this.testScrollState=testScrollState;
}
Activity 继承自 TestScrollState接口 , 实现对应的方法 ;
@Override
public void upAndDownState(boolean b) {
// getFloatingActionsMenu().show();
Log.i("Ledou", "State :" + b);
Log.i("Ledou","Btn_State :"+getFloatingActionsMenu().getVisible());
if(b==false){
hideFloatingButton();
}else{
showFloatingButton();
}
}
public void hideFloatingButton(){
if(getFloatingActionsMenu().getVisible()==false) {
getFloatingActionsMenu().show(true);
}
}
public void showFloatingButton(){
if(getFloatingActionsMenu().getVisible()==true) {
getFloatingActionsMenu().show(false);
}
}