Question

我一直收到错误：

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

每当执行以下操作时：

@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);
}

什么时候没有意义，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，因此inflater应该返回LinearLayout，它在哪里得到FrameLayout？

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);

修改

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项，例如LinearLayout，您必须从findViewById访问它，例如：

您的商品布局

<?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>

您的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);
 }

layoutInflater.inflate（...）上的ClassCastException

1 个答案: