LayoutInflater.inflate上的ClassCastException (...)

Question

我一直收到错误：

java.lang.ClassCastException: android.widget.FrameLayout cannot be cast to android.widget.LinearLayout

每当执行以下命令时：

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    LayoutInflater layoutInflater = LayoutInflater.from(parent.getContext());
    LinearLayout mLinearLayout = (LinearLayout) layoutInflater.inflate(R.layout.item, parent, false);
    return new ViewHolder(mLinearLayout);
}

When没有任何意义，因为这是我的xml文件：

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

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/item_text_view"/>

</LinearLayout>

因此，XML文件的根应该是LinearLayout，所以膨胀器应该返回LinearLayout，它从哪里获得FrameLayout呢？

Answer 1

替换

LinearLayout mLinearLayout = (LinearLayout) layoutInflater.inflate(R.layout.item, parent, false);
return new ViewHolder(mLinearLayout);

通过

View view = layoutInflater.inflate(R.layout.item, parent, false);
return new ViewHolder(view);

编辑

ViewHolder的公共构造函数需要View，而不是LinearLayout。如果您需要访问此布局的子级，例如必须从findViewById访问的LinearLayout，例如：

您的项目布局

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

<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/item_text_view"/>

</LinearLayout>

你的ViewHolder

public class ExampleViewHolder extends RecyclerView.ViewHolder{

    public ExampleViewHolder(View itemView) {
        super(itemView);
        LinearLayout linearLayout = (LinearLayout) itemView.findViewById(R.id.your_linear_layout_id);
    }
}

onCreateViewHolder

 @Override
 public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View view = layoutInflater.inflate(R.layout.item, parent, false);
   return new ViewHolder(view);
 }