Android.View.ContextThemeWrapper不能强制转换为Android.App.Activity

Question

我不是一个设计师，但当我得到这个项目，我不能打开特别的一些屏幕，我认为他们是屏幕，我们只重用一些布局已经创建。不管怎么说谁能帮帮我吗？@override public void onBindViewHolder(@nonnull final ProductsAdapter.ViewHolder holder,final int position）{String imageUrl=ProductsList.Get（position）.GetImage（）；

    holder.itemName.setText(ProductsList.get(position).getName());
    Picasso.with(context).load(imageUrl).into(holder.itemImage);

    holder.parentLayot.setOnClickListener(new View.OnClickListener() {
        public String currentActivity;

        @Override
        public void onClick(View v) {
            Activity activity = (Activity) v.getContext();
            activity.runOnUiThread(bd);
            String activityName = activity.getClass().getSimpleName();
            // Toast.makeText(activity,ProductsList.get(position).getId(),Toast.LENGTH_SHORT).show();

            if (activityName.equals("Product_View")){
                // Toast.makeText(activity,"Click and pass",Toast.LENGTH_SHORT).show();

                Intent intent = new Intent(activity, Second_Product_View.class);
                intent.putExtra("item_name", ProductsList.get(position).getName());
                intent.putExtra("item_id", ProductsList.get(position).getId());
                intent.putExtra("item_category_name", ProductsList.get(position).getName());
                intent.putExtra("item_category_id", ProductsList.get(position).getId());

                activity.startActivity(intent);
            } else if(activityName.equals("Second_Product_View")){
                Intent intent = new Intent(activity, Third_Product_View.class);

                intent.putExtra("item_category_name", activity.getIntent().getStringExtra("item_category_name"));
                intent.putExtra("item_category_id", activity.getIntent().getStringExtra("item_category_id"));

                intent.putExtra("item_subcategory_name", ProductsList.get(position).getName());
                intent.putExtra("item_subcategory_id", ProductsList.get(position).getId());

                intent.putExtra("item_name", ProductsList.get(position).getName());
                intent.putExtra("item_id", ProductsList.get(position).getId());

                activity.startActivity(intent);
            } else if(activityName.equals("Third_Product_View")){
                Intent intent = new Intent(activity, Fourth_Product_View.class);

                intent.putExtra("item_category_name", activity.getIntent().getStringExtra("item_category_name"));
                intent.putExtra("item_category_id", activity.getIntent().getStringExtra("item_category_id"));

                intent.putExtra("item_subcategory_name", activity.getIntent().getStringExtra("item_subcategory_name"));
                intent.putExtra("item_subcategory_id", activity.getIntent().getStringExtra("item_subcategory_id"));

                intent.putExtra("item_section_name", ProductsList.get(position).getName());
                intent.putExtra("item_section_id", ProductsList.get(position).getId());

                intent.putExtra("item_name", ProductsList.get(position).getName());
                intent.putExtra("item_id", ProductsList.get(position).getId());
                activity.startActivity(intent);
            } else if(activityName.equals("Fourth_Product_View")){
                holder.downloadManager = (DownloadManager)activity.getSystemService(Context.DOWNLOAD_SERVICE);
                String file = activity.getString(R.string.base_url) + "files/example-" + ProductsList.get(position).getId() + ".pdf";
                Uri uri = Uri.parse(file);
                DownloadManager.Request request = new DownloadManager.Request(uri);
                request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
                Long reference = holder.downloadManager.enqueue(request);
            } else if (activityName.equals("Formation_View")){
                Intent intent = new Intent(activity, Second_Formation_View.class);
                intent.putExtra("item_name", ProductsList.get(position).getName());
                intent.putExtra("item_id", ProductsList.get(position).getId());
                intent.putExtra("item_category_name", ProductsList.get(position).getName());
                intent.putExtra("item_category_id", ProductsList.get(position).getId());

                activity.startActivity(intent);
            } else if(activityName.equals("Second_Formation_View")){
                Intent intent = new Intent(activity, Third_Formation_View.class);

                intent.putExtra("item_category_name", activity.getIntent().getStringExtra("item_category_name"));
                intent.putExtra("item_category_id", activity.getIntent().getStringExtra("item_category_id"));

                intent.putExtra("item_subcategory_name", ProductsList.get(position).getName());
                intent.putExtra("item_subcategory_id", ProductsList.get(position).getId());

                intent.putExtra("item_name", ProductsList.get(position).getName());
                intent.putExtra("item_id", ProductsList.get(position).getId());

                activity.startActivity(intent);
            } else if(activityName.equals("Third_Formation_View")){
                holder.downloadManager = (DownloadManager)activity.getSystemService(Context.DOWNLOAD_SERVICE);
                String file = activity.getString(R.string.base_url) + "files/example-" + ProductsList.get(position).getId() + ".pdf";
                Uri uri = Uri.parse(file);
                DownloadManager.Request request = new DownloadManager.Request(uri);
                request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
                Long reference = holder.downloadManager.enqueue(request);
            } else if (activityName.equals("Tools_View")){
                Intent intent = new Intent(activity, Second_Tools_View.class);
                intent.putExtra("item_name", ProductsList.get(position).getName());
                intent.putExtra("item_id", ProductsList.get(position).getId());
                intent.putExtra("item_category_name", ProductsList.get(position).getName());
                intent.putExtra("item_category_id", ProductsList.get(position).getId());

                activity.startActivity(intent);
            } else if(activityName.equals("Second_Tools_View")){
                holder.downloadManager = (DownloadManager)activity.getSystemService(Context.DOWNLOAD_SERVICE);
                String file = activity.getString(R.string.base_url) + "files/example-" + ProductsList.get(position).getId() + ".pdf";
                Uri uri = Uri.parse(file);
                DownloadManager.Request request = new DownloadManager.Request(uri);
                request.setNotificationVisibility(DownloadManager.Request.VISIBILITY_VISIBLE_NOTIFY_COMPLETED);
                Long reference = holder.downloadManager.enqueue(request);
            }

        }
    });
} 

logcat显示了这一点

java.lang.ClassCastException: android.view.ContextThemeWrapper cannot be cast to android.app.Activity

    at android.view.View.performClick(View.java:6256)
    at android.view.View$PerformClick.run(View.java:24701)
    at android.os.Handler.handleCallback(Handler.java:789)
    at android.os.Handler.dispatchMessage(Handler.java:98)
    at android.os.Looper.loop(Looper.java:164)
    at android.app.ActivityThread.main(ActivityThread.java:6541)
    at java.lang.reflect.Method.invoke(Native Method)
    at 

Answer 1

Kotlin中的递归解法；

fun Context.getActivity(): Activity? {
    return when (this) {
        is Activity -> this
        is ContextWrapper -> this.baseContext.getActivity()
        else -> null
    }
}

在使用view.getContext()的情况下选中。

Answer 2

这句台词很可能就是罪魁祸首：

Activity activity = (Activity) v.getContext();

传递给onClick()方法的视图V与您为侦听器分配的视图相同，因此V与Holder.ParentLayot相同。我不知道holder.parentlayot到底从何而来，但很有可能（在XML中）这个视图（或其父视图之一）具有android:theme属性。

当视图具有android:theme属性时，它不会直接使用其activity的上下文。相反，android框架将activity的上下文“包装”在ContextThemeWrapper中，以便修改视图的主题。

要从这个包装器访问activity，您必须“打开”它。试试这样的方法：

private static Activity unwrap(Context context) {
    while (!(context instanceof Activity) && context instanceof ContextWrapper) {
        context = ((ContextWrapper) context).getBaseContext();
    }

    return (Activity) context;
}

然后，您可以在onclick()中使用此方法，而不是直接强制转换上下文：

Activity activity = unwrap(v.getContext());