Android - Fragment 控件Activity里的控件并的显示与隐藏

问题 : 

     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.

基本结构: 

      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;

效果演示 :

解决步揍:

   1. FloatingActionButton 在 BaseActivity 中

      (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;
}

     

   2.回调实现

      (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);

}

     (2) 实现 RecyclerView ScrollListener 监听事件
          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);
}

}
}

   (3)整个 Fragment的 代码 : 
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<Object> mContentItems = new ArrayList<>();
TestScrollState TScrollState;

public RecyclerViewFragment(TestScrollState TScrollState) {
this.TScrollState = TScrollState;
}

// public static RecyclerViewFragment newInstance() {
// return new RecyclerViewFragment(TScrollState);
// }

@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_wei_recyclerview, container, false);
}

@Override
public void onViewCreated(View view, @Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
mRecyclerView = (RecyclerView) view.findViewById(R.id.recyclerView);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getActivity());
mRecyclerView.setLayoutManager(layoutManager);
mRecyclerView.setHasFixedSize(true);

mAdapter = new RecyclerViewMaterialAdapter(new WeiRecyclerViewAdapter(mContentItems));
mRecyclerView.setAdapter(mAdapter);

{
for (int i = 0; i < ITEM_COUNT; ++i)
mContentItems.add(new Object());
mAdapter.notifyDataSetChanged();
}
mRecyclerView.addOnScrollListener(new ScrollListListener());
MaterialViewPagerHelper.registerRecyclerView(getActivity(), mRecyclerView, null);
}

/**
* 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);
}

}
}

public interface TestScrollState {
//滑动的状态 true 为 向上滑动,false 向下滑动
public void upAndDownState(boolean b);

}

}

3.在Adapter中作为参数传递

private RecyclerViewFragment.TestScrollState testScrollState;

public WeiViewPagerAdapter(FragmentManager fm,RecyclerViewFragment.TestScrollState testScrollState) {
super(fm);
this.testScrollState=testScrollState;
}

4.在子 Activity 中实现 接口

      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();
}
}

    显示和隐藏的两个方法 :
public void hideFloatingButton(){
if(getFloatingActionsMenu().getVisible()==false) {
getFloatingActionsMenu().show(true);
}
}

public void showFloatingButton(){
if(getFloatingActionsMenu().getVisible()==true) {
getFloatingActionsMenu().show(false);
}
}