Question

问题

如何从RecyclerViewHolder访问工具栏及其子代？我想使用LongClick从RecyclerViewHolder更改toolbar_main中的textView。

我所知道的

我知道如何使用

从onCreate内部的activty访问工具栏

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayShowTitleEnabled(false);
    txtTitle = (TextView) toolbar.findViewById(R.id.txtTitle);
    rbSelectAll = (RadioButton)toolbar.findViewById(R.id.rbSelectAll);
    rbSelectAll.setVisibility(GONE);
    txtTitle.setText("Gallerie");

RecyclerViewAdapter.java

public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewHolders> {

    private List<ItemObject> itemList;
    private Context context;
    private boolean isDir;

    public RecyclerViewAdapter(Context context, List<ItemObject> itemList, boolean isDir) {
        this.itemList = itemList;
        this.isDir = isDir;
        this.context = context;
    }

    @Override
    public RecyclerViewHolders onCreateViewHolder(ViewGroup parent, int viewType) {
        View layoutView = LayoutInflater.from(parent.getContext()).inflate(R.layout.card_view_list, null);
        RecyclerViewHolders rcv = new RecyclerViewHolders(layoutView, itemList, context);
        return rcv;
    }

    @Override
    public void onBindViewHolder(final RecyclerViewHolders holder, int position) {

        if(isDir){
            File[] fileNames = null;
            Log.v("Folder: ", itemList.get(position).getName());

            File path = new File(itemList.get(position).getName());
            if(path.exists()){
                fileNames = path.listFiles();
            }

            int i = 0;
            while(fileNames[i].isDirectory()){
                i++;
            }

            Glide.with(context).asBitmap()
                    .load(fileNames[i])
                    .thumbnail(0.2f)
                    .into(holder.countryPhoto);

            holder.selected.setVisibility(GONE);
            holder.albumName.setText(itemList.get(position).getName().substring(itemList.get(position).getName().lastIndexOf("/")+1));
            holder.countImages.setText(""+listFiles(itemList.get(position).getName()).size());

        }else {
            holder.selected.setVisibility(GONE);
            holder.albumName.setVisibility(GONE);
            holder.countImages.setVisibility(GONE);
            Glide.with(context).asBitmap()
                    .load(itemList.get(position).getName())
                    .thumbnail(0.2f)
                    .into(holder.countryPhoto);
        }
    }
}

RecyclerViewHolders.java

public class RecyclerViewHolders extends RecyclerView.ViewHolder implements View.OnClickListener, View.OnLongClickListener{

    public TextView albumName, countImages, txtName;
    public ImageView countryPhoto;
    private List<ItemObject> itemList;
    public RadioButton selected, selectAll;

    public RecyclerViewHolders(View itemView, List<ItemObject> itemList, Context context) {
        super(itemView);
        itemView.setOnClickListener(this);
        itemView.setOnLongClickListener(this);
        this.itemList = itemList;

        selected = (RadioButton)itemView.findViewById(R.id.rbSelected);
        albumName = (TextView)itemView.findViewById(R.id.albumName);
        countImages = (TextView)itemView.findViewById(R.id.countImages);
        countryPhoto = (ImageView)itemView.findViewById(R.id.country_photo);
    }

    @Override
    public void onClick(View view) {
        Toast.makeText(view.getContext(), "Clicked " + getPosition() + " " + itemList.get(getPosition()).getName(), Toast.LENGTH_SHORT).show();
    }

    @Override
    public boolean onLongClick(View view) {
        Toast.makeText(view.getContext(), "Long Clicked " + getPosition() + " " + itemList.get(getPosition()).getName(), Toast.LENGTH_SHORT).show();
        if(selected.isChecked()){
            selected.setVisibility(View.GONE);
            selected.setChecked(false);
        }else{
            selected.setVisibility(VISIBLE);
            selected.setChecked(true);
        }
        return true;
    }

}

activity_main.xml中

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/container"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context="com.spicysoftware.myapplication.MainActivity">

    <include
        android:id="@+id/toolbarPictures"
        layout="@layout/toolbar_main"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>

    <FrameLayout
        android:id="@+id/content"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1">

        <RelativeLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:padding="8dp"
            tools:context=".MainActivity">

            <android.support.v7.widget.RecyclerView
                android:id="@+id/recycler_view"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:scrollbars="vertical" />

        </RelativeLayout>

    </FrameLayout>

    <android.support.design.widget.BottomNavigationView
        android:id="@+id/navigation"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:background="?android:attr/windowBackground"
        app:menu="@menu/navigation" />

</LinearLayout>

toolbar_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.design.widget.AppBarLayout
        android:id="@+id/appBarLayout"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:theme="@style/AppTheme.AppBarOverlay">


        <android.support.v7.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="?attr/actionBarSize"
            android:background="#5fb0c9"
            android:elevation="4dp"
            android:theme="@style/ThemeOverlay.AppCompat.ActionBar"
            app:popupTheme="@style/ThemeOverlay.AppCompat.Light">

            <TextView
                android:id="@+id/txtTitle"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_weight="1"
                android:text="TextView"
                android:textColor="@android:color/white"
                android:textSize="18sp"
                android:textStyle="bold" />

        </android.support.v7.widget.Toolbar>
    </android.support.design.widget.AppBarLayout>
</LinearLayout>

Answer 1

步骤1：为RecyclerViewOnItemClick

创建一个类和接口

RecyclerTouchListener.java

public class RecyclerTouchListener implements RecyclerView.OnItemTouchListener{

    private IOnRecyclerItemClickedListener clicklistener;
    private GestureDetector gestureDetector;

    public RecyclerTouchListener(Context context, final RecyclerView recycleView, final IOnRecyclerItemClickedListener clicklistener){

        this.clicklistener=clicklistener;
        gestureDetector=new GestureDetector(context,new GestureDetector.SimpleOnGestureListener(){
            @Override
            public boolean onSingleTapUp(MotionEvent e) {
                return true;
            }

            @Override
            public void onLongPress(MotionEvent e) {
                View child=recycleView.findChildViewUnder(e.getX(),e.getY());
                if(child!=null && clicklistener!=null){
                    clicklistener.onLongClick(child,recycleView.getChildAdapterPosition(child));
                }
            }
        });
    }

    @Override
    public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
        View child=rv.findChildViewUnder(e.getX(),e.getY());
        if(child!=null && clicklistener!=null && gestureDetector.onTouchEvent(e)){
            clicklistener.onClick(child,rv.getChildAdapterPosition(child));
        }

        return false;
    }

    @Override
    public void onTouchEvent(RecyclerView rv, MotionEvent e) {

    }
    @Override
    public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {

    }
}

接口IOnRecyclerItemClickedListener.java

public interface IOnRecyclerItemClickedListener {
    public void onRecyclerItemClick(View view, int position);
    public void onRecyclerItemLongClick(View view,int position);
}

第2步：在您的活动中实施IOnRecyclerItemClickedListener

YourActivity.java

public class YourActivity extends Fragment implements IOnRecyclerItemClickedListener{

private Toolbar toolbar;
@Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setDisplayShowTitleEnabled(false);
        txtTitle = (TextView) toolbar.findViewById(R.id.txtTitle);
        rbSelectAll = (RadioButton)toolbar.findViewById(R.id.rbSelectAll);
    rbSelectAll.setVisibility(GONE);
    txtTitle.setText("Gallerie");
    }

@Override
    public void onRecyclerItemLongClick(View view, int position) {
       toolbar.setTitle("Title that you want to display");
    }


    @Override
    public void onRecyclerItemClick(View v) {

        }
    }
}

我希望这个答案可以帮到你!!

Answer 2

你不应该把两个完全独立的视图结合起来。您应该定义Activity应该实现的onLongClick接口，并在ViewHolder的构造函数内的每个itemView上设置它，然后执行工具栏功能。

Answer 3

((MainActivity) context).toolbar

或者（（MainActivity）context）.findViewById（R.id.toolbar）

Answer 4

您可以使用界面来实现您的目标，如下所示。

创建一个界面。

public interface DummyInterface {
    public void doSomethingWithToolbar();
}

然后在您的活动上实施此界面。

public class DummyActivity extends Activity implements DummyInterface {
    .
    .
    .
    public void doSomethingWithToolbar() {
        //do something with toolbar
    }
}

然后在构造函数中创建recycleler视图时传递this（activity）的引用。像，

new DummyRecyclerView(..., this);

然后在RecyclerView的构造函数中添加一个参数。像，

DummyInterface dummy = new DummyInterface();
public DummyRecyclerView(..., DummyInterface d) {
    dummy = d;
}

然后将dummy传递给RecyclerViewHolder的构造函数，并将它添加到RecyclerViewHolder的构造函数中的参数，就像我们从Activity到RecyclerView一样。您可以使用doSomethingWithToolbar从RecyclerViewHolder调用方法dummy.doSomethingWithToolbar()。

Android：如何从RecyclerViewHolder访问工具栏？

4 个答案: