AppCompatImageView不能投向com.squareup.picasso.Target [关闭] 。

Question

结束了。 这个问题是 不可复制或由错别字造成的。. 目前不接受回答。

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想改进这个问题？ 请更新问题，使之成为 题外话 为Stack Overflow。

已关闭 20天前.

改进这个问题

我正试图将Firebase数据库中的图片上传到一个帖子布局中，每当我上传图片时，应用程序就会崩溃，我得到这个错误。

java.lang.ClassCastException: androidx.appcompat.widget.AppCompatImageView cannot be cast to com.squareup.picasso.Target
    at com.example.app.MainActivity$3.onBindViewHolder(MainActivity.java:164)
    at com.example.app.MainActivity$3.onBindViewHolder(MainActivity.java:159)
    at com.firebase.ui.database.FirebaseRecyclerAdapter.onBindViewHolder(FirebaseRecyclerAdapter.java:149)
    at androidx.recyclerview.widget.RecyclerView$Adapter.onBindViewHolder(RecyclerView.java:7065)
    at androidx.recyclerview.widget.RecyclerView$Adapter.bindViewHolder(RecyclerView.java:7107)
    at androidx.recyclerview.widget.RecyclerView$Recycler.tryBindViewHolderByDeadline(RecyclerView.java:6012)
    at androidx.recyclerview.widget.RecyclerView$Recycler.tryGetViewHolderForPositionByDeadline(RecyclerView.java:6279)
    at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:6118)
    at androidx.recyclerview.widget.RecyclerView$Recycler.getViewForPosition(RecyclerView.java:6114)
    at androidx.recyclerview.widget.LinearLayoutManager$LayoutState.next(LinearLayoutManager.java:2303)
    at androidx.recyclerview.widget.LinearLayoutManager.layoutChunk(LinearLayoutManager.java:1627)
    at androidx.recyclerview.widget.LinearLayoutManager.fill(LinearLayoutManager.java:1587)
    at androidx.recyclerview.widget.LinearLayoutManager.onLayoutChildren(LinearLayoutManager.java:665)
    at androidx.recyclerview.widget.RecyclerView.dispatchLayoutStep2(RecyclerView.java:4134)
    at androidx.recyclerview.widget.RecyclerView.dispatchLayout(RecyclerView.java:3851)
    at androidx.recyclerview.widget.RecyclerView.consumePendingUpdateOperations(RecyclerView.java:1897)
    at androidx.recyclerview.widget.RecyclerView$1.run(RecyclerView.java:414)
    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:966)
    at android.view.Choreographer.doCallbacks(Choreographer.java:790)
    at android.view.Choreographer.doFrame(Choreographer.java:721)
    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:951)
    at android.os.Handler.handleCallback(Handler.java:883)
    at android.os.Handler.dispatchMessage(Handler.java:100)
    at android.os.Looper.loop(Looper.java:214)
    at android.app.ActivityThread.main(ActivityThread.java:7356)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

我不知道这意味着什么，我也没有找到类似问题的人。以下是我的style.xml

<resources>

<!-- Base application theme. -->
<style name="AppTheme" parent="Base.Theme.AppCompat.Light.DarkActionBar">
    <!-- Customize your theme here. -->
    <item name="colorPrimary">@color/colorPrimary</item>
    <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
    <item name="color">#0F2926</item>
    <item name="windowNoTitle">true</item>
    <item name="windowActionBar">false</item>
</style>

最后，这里是涉及到Picasso的代码，我认为错误发生在这里。

  private void DisplayAllUsersPosts()
{
    FirebaseRecyclerOptions<Posts> options =
            new FirebaseRecyclerOptions.Builder<Posts>()
                    .setQuery(PostsRef, Posts.class)
                    .build();

    FirebaseRecyclerAdapter<Posts, PostsViewHolder> firebaseRecyclerAdapter =
            new FirebaseRecyclerAdapter<Posts, PostsViewHolder> (options)
            {
                @Override
                protected void onBindViewHolder(@NonNull PostsViewHolder holder, int position, @NonNull Posts model)
                {
                    holder.Description.setText(model.getDescription());
                    Picasso.get().load(model.getImage()).into((Target) holder.Image);
                }

                @NonNull
                @Override
                public PostsViewHolder onCreateViewHolder(@NonNull ViewGroup viewGroup, int viewType)
                {
                    View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.all_posts_layout, viewGroup, false);
                    PostsViewHolder viewHolder = new PostsViewHolder(view);
                    return viewHolder;
                }
            };

    firebaseRecyclerAdapter.startListening();

    postList.setAdapter(firebaseRecyclerAdapter);
}

Answer 1

你得到的是以下错误。

java.lang.ClassCastException: androidx.appcompat.widget.AppCompatImageView cannot be cast to com.squareup.picasso.Target。

在下面这行代码中。

Picasso.get().load(model.getImage()).into((Target) holder.Image);

因为你正在尝试投射一个类型的对象。AppCompatImageView 类型的对象。Target，这在Java中其实是不可能的。要解决这个问题，只需删除不必要的铸造。

Picasso.get().load(model.getImage()).into(holder.Image);