隐藏查看Propolis to RecyclerView滚动

在我的android应用程序中，我有一个recyclerview和LinearLayout。 LinearLayout位于顶部，而recyclerview位于线性布局。我的要求是什么时候recyclerview开始滚动最后一个项目，linearlayout应该开始隐藏在propotion中滚动数量。隐藏查看Propolis to RecyclerView滚动

我做了一点，它的工作原理。但它与滚动量不成比例。这里是我的代码

ScrollListener

public class MyScrollListener extends OnScrollListener { 

    private LinearLayoutManager mLayoutManager; 

    public MyScrollListener(LinearLayoutManager manager) { 
     this.mLayoutManager = manager; 
    } 

    @Override 
    public void onScrolled(RecyclerView recyclerView, int dx, int dy) { 

     int visibleItemCount = mLayoutManager.getChildCount(); 
     int totalItemCount = mLayoutManager.getItemCount(); 
     int firstVisibleItem = mLayoutManager.findFirstVisibleItemPosition(); 

     if (visibleItemCount + firstVisibleItem >= totalItemCount) { 
      scrollTheShit(dy * -1, ((View) recyclerView.getChildAt(visibleItemCount - 1)).getWidth()); 
     } 
    } 

    public void scrollTheShit(int dy, int widthOfLastChild) {} 


}

MainActivity

public class MainActivity extends AppCompatActivity { 

    RecyclerView recyclerView; 
    LinearLayout linearLayout; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     linearLayout = (LinearLayout) findViewById(R.id.container); 
     recyclerView = (RecyclerView) findViewById(R.id.my_recycler_view); 
     recyclerView.setHasFixedSize(true); 
     final LinearLayoutManager mgr = new LinearLayoutManager(this); 
     recyclerView.setLayoutManager(mgr); 
     recyclerView.setAdapter(new RecyclerAdapter()); 


     recyclerView.addOnScrollListener(new MyScrollListener(mgr) { 

      @Override 
      public void scrollTheShit(int dy, int widthOfLastChild) { 

       linearLayout.setY(linearLayout.getY() + dy); 
      } 
     }); 
    } 


    private class RecyclerAdapter extends Adapter<RecyclerAdapter.ViewHolder> { 


     @Override 
     public int getItemCount() { 
      return 10; 
     } 

     @Override 
     public void onBindViewHolder(ViewHolder viewHolder, 
            int position) { 
     } 

     @Override 
     public ViewHolder onCreateViewHolder(ViewGroup parent, int position) { 
      View v = LayoutInflater.from(MainActivity.this) 
        .inflate(R.layout.child, parent, false); 
      ViewHolder holder = new ViewHolder(v); 
      return holder; 
     } 

     public class ViewHolder extends RecyclerView.ViewHolder { 

      public ViewHolder(View arg0) { 
       super(arg0); 
      } 

     } 
    } 

}

我不得不隐藏在下面RecyclerView滚动

我怎么纠正顶部这个？请人帮我

来源

2015-09-02 droidev

我如果你可以显示一些图片或视频来说明你在上面的图片中究竟是什么 –

，那么hello world textview和编辑文本在linearlayout中，当用户开始滚动recyclerview的最后一项时，t会更好。然后顶视图必须隐藏 – droidev

好吧，我做了一个小例子，你看看它http://amolsawant88.blogspot.in/2015/09/hideshow-view-or-layout-propotionalto.html –

这可能会帮助你

QuickReturnRecyclerView.java

import android.content.Context; 
import android.os.Build; 
import android.support.v7.widget.RecyclerView; 
import android.util.AttributeSet; 
import android.view.Gravity; 
import android.view.View; 
import android.view.ViewGroup; 
import android.view.animation.TranslateAnimation; 
import android.widget.FrameLayout; 

public class QuickReturnRecyclerView extends RecyclerView { 
    private static final String TAG = QuickReturnRecyclerView.class.getName(); 

    private View mReturningView; 
    private static final int STATE_ONSCREEN = 0; 
    private static final int STATE_OFFSCREEN = 1; 
    private static final int STATE_RETURNING = 2; 
    private int mState = STATE_ONSCREEN; 
    private int mMinRawY = 0; 
    private int mReturningViewHeight; 
    private int mGravity = Gravity.BOTTOM; 

    public QuickReturnRecyclerView(Context context) { 
     super(context); 
     init(); 
    } 

    public QuickReturnRecyclerView(Context context, AttributeSet attrs) { 
     super(context, attrs); 
     init(); 
    } 

    public QuickReturnRecyclerView(Context context, AttributeSet attrs, int defStyle) { 
     super(context, attrs, defStyle); 
     init(); 
    } 

    private void init(){ 
    } 

    /** 
    * The view that should be showed/hidden when scrolling the content. 
    * Make sure to set the gravity on the this view to either Gravity.Bottom or 
    * Gravity.TOP and to put it preferable in a FrameLayout. 
    * @param view Any kind of view 
    */ 
    public void setReturningView(View view) { 
     mReturningView = view; 

     try { 
      FrameLayout.LayoutParams params = (FrameLayout.LayoutParams) mReturningView.getLayoutParams(); 
      mGravity = params.gravity; 
     } catch (ClassCastException e) { 
      throw new RuntimeException("The return view need to be put in a FrameLayout"); 
     } 

     measureView(mReturningView); 
     mReturningViewHeight = mReturningView.getMeasuredHeight(); 
     addOnScrollListener(new RecyclerScrollListener()); 
    } 

    private void measureView(View child) { 
     ViewGroup.LayoutParams p = child.getLayoutParams(); 
     if (p == null) { 
      p = new ViewGroup.LayoutParams(
        ViewGroup.LayoutParams.FILL_PARENT, 
        ViewGroup.LayoutParams.WRAP_CONTENT); 
     } 

     int childWidthSpec = ViewGroup.getChildMeasureSpec(0, 0, p.width); 
     int lpHeight = p.height; 
     int childHeightSpec; 
     if (lpHeight > 0) { 
      childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY); 
     } else { 
      childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED); 
     } 
     child.measure(childWidthSpec, childHeightSpec); 
    } 

    private class RecyclerScrollListener extends OnScrollListener { 
     private int mScrolledY; 

     @Override 
     public void onScrolled(RecyclerView recyclerView, int dx, int dy) { 
      if(mGravity == Gravity.BOTTOM) 
       mScrolledY += dy; 
      else if(mGravity == Gravity.TOP) 
       mScrolledY -= dy; 

      if(mReturningView == null) 
       return; 

      int translationY = 0; 
      int rawY = mScrolledY; 

      switch (mState) { 
       case STATE_OFFSCREEN: 
        if(mGravity == Gravity.BOTTOM) { 
         if (rawY >= mMinRawY) { 
          mMinRawY = rawY; 
         } else { 
          mState = STATE_RETURNING; 
         } 
        } else if(mGravity == Gravity.TOP) { 
         if (rawY <= mMinRawY) { 
          mMinRawY = rawY; 
         } else { 
          mState = STATE_RETURNING; 
         } 
        } 

        translationY = rawY; 
        break; 

       case STATE_ONSCREEN: 
        if(mGravity == Gravity.BOTTOM) { 

         if (rawY > mReturningViewHeight) { 
          mState = STATE_OFFSCREEN; 
          mMinRawY = rawY; 
         } 
        } else if(mGravity == Gravity.TOP) { 

         if (rawY < -mReturningViewHeight) { 
          mState = STATE_OFFSCREEN; 
          mMinRawY = rawY; 
         } 
        } 
        translationY = rawY; 
        break; 

       case STATE_RETURNING: 
        if(mGravity == Gravity.BOTTOM) { 
         translationY = (rawY - mMinRawY) + mReturningViewHeight; 

         if (translationY < 0) { 
          translationY = 0; 
          mMinRawY = rawY + mReturningViewHeight; 
         } 

         if (rawY == 0) { 
          mState = STATE_ONSCREEN; 
          translationY = 0; 
         } 

         if (translationY > mReturningViewHeight) { 
          mState = STATE_OFFSCREEN; 
          mMinRawY = rawY; 
         } 
        } else if(mGravity == Gravity.TOP) { 
         translationY = (rawY + Math.abs(mMinRawY)) - mReturningViewHeight; 

         if (translationY > 0) { 
          translationY = 0; 
          mMinRawY = rawY - mReturningViewHeight; 
         } 

         if (rawY == 0) { 
          mState = STATE_ONSCREEN; 
          translationY = 0; 
         } 

         if (translationY < -mReturningViewHeight) { 
          mState = STATE_OFFSCREEN; 
          mMinRawY = rawY; 
         } 
        } 
        break; 
      } 

      /** this can be used if the build is below honeycomb **/ 
      if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.HONEYCOMB) { 
       TranslateAnimation anim = new TranslateAnimation(0, 0, translationY, translationY); 
       anim.setFillAfter(true); 
       anim.setDuration(0); 
       mReturningView.startAnimation(anim); 
      } else { 
       mReturningView.setTranslationY(translationY); 
      } 
     } 
    } 
}

activity_main.xml中

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" 
    xmlns:app="http://schemas.android.com/apk/res-auto" 
    android:layout_width="fill_parent" 
    android:layout_height="fill_parent"> 

    <yourpackagename.QuickReturnRecyclerView 
     android:id="@+id/recycler_view" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     android:scrollbars="vertical" /> 

    <LinearLayout 
     android:id="@+id/linear" 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:layout_gravity="top" 
     android:background="@android:color/darker_gray" 
     android:orientation="horizontal" 
     android:padding="15dp"> 

     <Button 
      android:id="@+id/button" 
      android:layout_width="0dp" 
      android:layout_height="wrap_content" 
      android:layout_gravity="left|top" 
      android:layout_weight="1" 
      android:text="New Button" /> 

     <Button 
      android:id="@+id/button2" 
      android:layout_width="0dp" 
      android:layout_height="wrap_content" 
      android:layout_gravity="center_horizontal|top" 
      android:layout_weight="1" 
      android:text="New Button" /> 

     <Button 
      android:id="@+id/button3" 
      android:layout_width="0dp" 
      android:layout_height="wrap_content" 
      android:layout_gravity="right|top" 
      android:layout_weight="1" 
      android:text="New Button" /> 
    </LinearLayout> 


</FrameLayout>

在MainActivity.java只需添加以下行

 mRecyclerView = (QuickReturnRecyclerView) findViewById(R.id.recycler_view); 
     linear = (LinearLayout) findViewById(R.id.linear); 
     // use this setting to improve performance if you know that changes 
     // in content do not change the layout size of the RecyclerView 
     mRecyclerView.setHasFixedSize(true); 

     // use a linear layout manager 
     mLayoutManager = new LinearLayoutManager(getApplicationContext()); 
     mRecyclerView.setLayoutManager(mLayoutManager); 

     mRecyclerView.setReturningView(linear);

来源

2015-09-02 07:38:47

隐藏查看Propolis to RecyclerView滚动

回答

相关问题