Question

在我的RecyclerView.ViewHolder中，我想检查是否有网络，如果它返回true，则取消隐藏进度条。

我使用此类检查网络连接：

public class NetworkCheck {

    public static boolean isAvailableAndConnected(Context context) {
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        boolean isNetworkAvailable = cm.getActiveNetworkInfo() != null;
        boolean isNetWorkConnected = isNetworkAvailable && cm.getActiveNetworkInfo().isConnected();

        return isNetWorkConnected;

    }

}

然后在RecyclerView.ViewHolder中我这样做：

public static class ProgressViewHolder extends RecyclerView.ViewHolder {
        Button loadButton;
        ProgressBar progressBar;
        public ProgressViewHolder(View footerView){
            super(footerView);
            loadButton = (Button) footerView.findViewById(R.id.reload_button);
            progressBar = (ProgressBar) footerView.findViewById(R.id.progress_load);

            if(NetworkCheck.isAvailableAndConnected(Context)) {
                loadButton.setVisibility(View.VISIBLE);

            }
        }
    }

在排行榜if(NetworkCheck.isAvailableAndConnected(Context)) { Android Studio红色下划线上下文中显示消息：＆＃34;表达式预期＆＃34;。我尝试过context，getApplicationContext，getBaseContext，this，但似乎都没有。

拜托，我在哪里弄错了？

Answer 1

如您所知，您需要Context inflate itemView onCreateViewHolder对象并使用Context方法创建持有者，因此请在适配器中保留一个实例，这样您就拥有了每次需要时对public class Adapter extends RecyclerView.Adapter<Adapter.ProgressViewHolder> { Context mContext //you need this to inflate views public Adapter(Context context, arguments you need...) { mContext = context; //here you keep an reference to Context object ... } ... static class ProgressViewHolder extends RecyclerView.ViewHolder { //your implementation } }对象的引用，如下所示：

Change:

Answer 2

您可以使用footerView对象检索上下文：

 public static class ProgressViewHolder extends RecyclerView.ViewHolder {
                //...
                 public ProgressViewHolder(View footerView){
                    if(NetworkCheck.isAvailableAndConnected(footerView.getContext())) {
                       // Do stuff

                }
            }

如何向RecyclerView.ViewHolder提供上下文参数

2 个答案: