如何在recyclerView中显示和隐藏imageview

Question

我正在使用 for 循环，并且我在回收站视图中显示了大约 20 个项目！现在我如何在 for 循环运行时隐藏/显示图像视图...这里 tts 工作正常，但是当我尝试使用它显示/隐藏时它没有发生..

目前使用下面的代码，一旦 for 循环结束整个 imageview 正在影响，我想要它一行 wis（显示当前（image1）和隐藏上一个 imageview（image））

我正在从主 Activity 类调用此方法，但图像视图显示或隐藏没有发生

活动

 ......
 ...... 
private void ConvertTextToSpeech() {
    // TODO Auto-generated method stub
   //items.forEach( Multiples obj ->  System.out.println());
    int z=0;
    View holder=null; ImageView imageView=null;ImageView imageView1=null;
    for (Multiples p : items) {

        if(z>0){

            holder = recyclerView.findViewHolderForAdapterPosition(z).itemView;
            holder.findViewById(R.id.image).setVisibility(View.VISIBLE);
            holder.findViewById(R.id.image1).setVisibility(View.INVISIBLE);
        }
        if(z < items.size()) {
              holder = recyclerView.findViewHolderForAdapterPosition(z).itemView;
              holder.findViewById(R.id.image).setVisibility(View.INVISIBLE);
            holder.findViewById(R.id.image1).setVisibility(View.VISIBLE);

        }
        text = p.first + "  " + p.getSecond() + " Za "+p.getResult()+".";
        tts.speak(text, TextToSpeech.QUEUE_ADD, null);
    z++;
    }

}

xml

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


    <com.balysv.materialripple.MaterialRippleLayout
        android:id="@+id/lyt_parent"
        style="@style/RippleStyleBlack"
        android:layout_width="match_parent"
        android:layout_height="?attr/actionBarSize"
        android:focusable="true">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical">

            <View
                android:layout_width="match_parent"
                android:layout_height="1px"
                android:background="@color/grey_10" />

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_weight="1"
                android:gravity="center_vertical"
                android:orientation="horizontal"
                android:textAlignment="gravity" >

                <View
                    android:layout_width="@dimen/spacing_large"
                    android:layout_height="wrap_content" />

                <ImageView
                    android:id="@+id/image"
                    android:layout_width="35dp"
                    android:layout_height="35dp"
                    android:background="@android:color/transparent"
                    android:src="@drawable/ic_arrow_right" />

                <ImageView
                    android:id="@+id/image1"
                    android:layout_width="51dp"
                    android:layout_height="35dp"
                    android:background="@android:color/transparent"
                    android:src="@drawable/ic_arrow_right"
                    android:visibility="invisible" />

                <LinearLayout
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:orientation="vertical"
                    android:paddingBottom="@dimen/spacing_middle"
                    android:paddingTop="@dimen/spacing_middle">

                    <TextView
                        android:id="@+id/name"
                        android:layout_width="wrap_content"
                        android:layout_height="wrap_content"
                        android:layout_marginEnd="@dimen/spacing_middle"
                        android:layout_marginRight="@dimen/spacing_middle"
                        android:fontFamily="sans-serif-condensed"
                        android:gravity="center|left"
                        android:text="36"
                        android:textAppearance="@style/TextAppearance.AppCompat.Medium"
                        android:textColor="@color/grey_80"
                        android:textSize="30sp"

                        />



                </LinearLayout>





                <View
                    android:layout_width="@dimen/spacing_large"
                    android:layout_height="match_parent" />


            </LinearLayout>

            <View
                android:layout_width="match_parent"
                android:layout_height="1px"
                android:background="@color/grey_10" />

        </LinearLayout>

    </com.balysv.materialripple.MaterialRippleLayout>

</RelativeLayout>

适配器

public class AdapterListAnimation extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

    private List<Multiples> items = new ArrayList<>();

    private Context ctx;
    private OnItemClickListener mOnItemClickListener;
    private int animation_type = 0;
    .........
    ......... 

Answer 1

您只需在适配器中添加字段即可保存当前活动项目。然后拨打notifyDataSetChanged。 你也应该像这样更新你的onBindViewHolder：

private int currentPosition = -1;

@Override
public void onBindViewHolder(@NonNull MyViewHolder holder, int position) {
    holder.textView.setText(items.get(position));
    if (currentPosition == position) {
        holder.img1.setVisibility(View.INVISIBLE);
        holder.img2.setVisibility(View.VISIBLE);
    } else {
        holder.img1.setVisibility(View.VISIBLE);
        holder.img2.setVisibility(View.INVISIBLE);
    }
}

public void setCurrentPosition(int currentPosition) {
    this.currentPosition = currentPosition;
}

我创建了一个测试项目来展示如何实现它。 Here 你可以看到它是如何工作的。 Here 是我的 github 仓库。

Answer 2

您不应使用以下内容直接更改适配器内的项目视图状态：

holder = recyclerView.findViewHolderForAdapterPosition(z).itemView;
holder.findViewById(R.id.image).setVisibility(View.VISIBLE);
holder.findViewById(R.id.image1).setVisibility(View.INVISIBLE);

相反，您需要使用特定方法告诉 RecyclerView 适配器您需要更改项目视图的状态。

请注意，当需要绘制另一个项目时，RecylerView 自然地（以编程方式）将回收它的前一个项目。因此，无论是在模型中使用特定变量还是使用变量来保存每个项目的状态，您都需要保持每个项目的状态。

如果您不想更改模型，可以使用 SparseBooleanArray 来保存状态。您可以在适配器中执行以下操作：

public class YourAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {

    private List<Multiples> mItems;

    // We use this to hold the image state.
    private SparseBooleanArray mImageStates;

    public YourAdapter(List<Multiples> items) {
      this.mItems = items;
      mImageStates = new SparseBooleanArray();

      ...
    }

    @Override
    public YourAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
       ...
       return viewHolder;
    }


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

      int itemPosition = viewHolder.getAdapterPosition();
      Multiples item = mItems.get(itemPosition);

      // Load the state by the previous saved state
      // default value is false.
      if(mImageStates.get(itemPosition)) {
        // show the images or something.
      } else {
        // hide the images or something.
      }

    }

    public void setState(int position, boolean isVisible) {
      mImageStates.put(position, isVisible);

    }

}

现在您可以通过以下方式更改状态项的可见性：

yourAdapter.setState(yourItemPosition, true);

然后将更改通知适配器：

yourAdapter.notifyItemChanged(yourItemPosition);

如果您更改了许多项目，则全部重置：

yourAdapter.notifyDataSetChanged();

Answer 3

你必须在 onbindholder 上写一个逻辑。

onBindHolder(ViewHolder holder, int position){
 if(position %2==0)
  imageview.setVisibility(View.Visible);
 else 
  imageview.setVisibility(View.InVisible);
}

Answer 4

终于找到解决方案了

我在您的倍数中添加了两个参数。在您的循环中，当条件为真时，我正在根据您对图像视图所做的设置变量。在我通知RecyclerView 之后。因此，onBindViewHolder 将出现回调。在那里我添加了显示/隐藏图像视图的条件。

假设左箭头是image，右箭头是image1

注意： Android 默认 TextToSpeech 不提供任何用于完成的事件侦听器。因此，我尝试了一个维护良好并提供Speech recognition 和Text to speech 功能的新库。

Gradle：

implementation 'net.gotev:speech:1.4.0'

初始化：

要开始使用该库，您必须在 Activity 中对其进行初始化。

public class YourActivity extends Activity {

private count = 0;
private maxCount = 0;

    Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.your_layout);

        Speech.init(this, getPackageName());
        maxCount = items.size();

    }

    @Override
    protected void onDestroy() {
        // prevent memory leaks when activity is destroyed
        Speech.getInstance().shutdown();
    }
}

public class Multiples implements Serializable {

        private Boolean isShowimage = false;
        private Boolean isShowimage1 = false;

        public Boolean getShowimage() {
            return isShowimage;
        }

        public void setShowimage(Boolean showimage) {
            isShowimage = showimage;
        }

        public Boolean getShowimage1() {
            return isShowimage1;
        }

        public void setShowimage1(Boolean showimage1) {
            isShowimage1 = showimage1;
        }
    }

private void ConvertTextToSpeech() {

    if (count < maxCount) {

        reset();
        String text = items.get(count).first + "  " + items.get(count).getSecond() + " Za " + items.get(count).getResult() + ".";

        Speech.getInstance().say(text, new TextToSpeechCallback() {
            @Override
            public void onStart() {
                Log.i("speech", "speech started");
                items.get(count).setShowimage(false);
                items.get(count).setShowimage1(true);

                adapter.notifyDataSetChanged();
            }

            @Override
            public void onCompleted() {
                Log.i("speech", "speech completed");
                ConvertTextToSpeech();
                count++;
            }

            @Override
            public void onError() {
                Log.i("speech", "speech error");
            }
        });
    }
}

private void reset() {
    for (Multiples p : items) {
        p.setShowimage(true);
        p.setShowimage1(false);
    }
}
@Override
    public void onBindViewHolder(ViewHolder holder, int position) {

        final Multiples item = items.get(position);

        if (item.getShowimage()) {
            holder.image.setVisibility(View.VISIBLE);
        } else {
            holder.image.setVisibility(View.INVISIBLE);
        }

        if (item.getShowimage1()) {
            holder.image1.setVisibility(View.VISIBLE);
        } else {
            holder.image1.setVisibility(View.INVISIBLE);
        }

    }

public static class ViewHolder extends RecyclerView.ViewHolder {
        private ImageView imageView,imageView1;

        public ViewHolder(View view) {
            super(view);
            this.imageView = (ImageView) view.findViewById(R.id.imageView);
            this.imageView1 = (ImageView) view.findViewById(R.id.imageView1);

        }
    }