我一直在努力解决这个问题。我有一个SQLiteDatabase，它存储鞋子的品牌名称，鞋子名称和鞋子的字节图像。我能够通过内容提供商将所有信息加载到recyclerview。但是当我尝试将信息加载到Recycler视图中的每个项目的详细信息时，详细信息活动会填充错误的信息，它会返回一个完全不同的条目，而不是我选择的条目。
我在许多YouTube视频中看到的解决方案都包含了我创建ArrayLists来存储信息的方法，但我发现使用我的SQLiteDatabase信息很难做到。
以下是我的课程...... 我的Closet.java类（使用我的getter方法）
<div *ngFor="let item of agendaData | async ">
{{ item.name }}
</div>
我的适配器类（CustomAdapter.java）
package com.example.android.myshoecloset;
import android.database.Cursor;
import android.os.Parcel;
import android.os.Parcelable;
/**
* Created by man on 12/21/2017.
*/
public class Closet
{
private static final String TAG = Closet.class.getSimpleName();
//Brand name
private final String brandName;
//Shoe Name
private final String shoeName;
//Image of the shoe
private final String shoeImage;
public Closet(String brandName, String shoeName, String shoeImage)
{
this.brandName = brandName;
this.shoeName = shoeName;
this.shoeImage = shoeImage;
}
public Closet(Cursor cursor)
{
this.brandName = null;
this.shoeName = null;
this.shoeImage = null;
}
public String getShoeImageName()
{
return shoeImage;
}
public String getBrandName()
{
return brandName;
}
public String getShoeName()
{
return shoeName;
}
}
My ClosetFragment，它将加载器上的信息加载到片段recyclelerview。
package com.example.android.myshoecloset.data;
/*Assume appropriate imports*/
/**
* Created by man on 11/23/2017.
*/
public class CustomAdapter extends RecyclerView.Adapter<CustomAdapter.TaskHolder> {
private Cursor mCursor;
private Context mContext;
public static String shoeName;
public static String brandName;
public static byte[] byteArray;
public CustomAdapter(Context mContext) {
this.mContext = mContext;
}
public CustomAdapter()
{
mContext = null;
}
/* ViewHolder for each task item */
public class TaskHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public TextView shoeBrandName;
public TextView shoeName;
public ImageView shoeImage;
public LinearLayout linearLayout;
public TaskHolder(final View itemView) {
super(itemView);
itemView.setOnClickListener(this);
shoeBrandName = (TextView) itemView.findViewById(R.id.textBrandName);
shoeImage = (ImageView) itemView.findViewById(R.id.shoeImage);
shoeName = (TextView) itemView.findViewById(R.id.textShoeName);
linearLayout = (LinearLayout) itemView.findViewById(R.id.linear_closet);
}
@Override
public void onClick(View v) {
Intent i = new Intent(v.getContext(), ShoeDetailActivity.class);
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
v.getContext().startActivity(i);
}
}
@Override
public TaskHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(mContext);
View itemView = inflater
.inflate(R.layout.text_row_item, parent, false);
return new TaskHolder(itemView);
}
@Override
public void onBindViewHolder(TaskHolder holder, int position) {
int idIndex = mCursor.getColumnIndex(DatabaseContract.ShoeColumns._ID);
int imgValue = mCursor.getColumnIndex(DatabaseContract.ShoeColumns.SHOE_IMAGE);
int shoeBrandName = mCursor.getColumnIndex(DatabaseContract.ShoeColumns.SHOE_BRAND);
int shoeName = mCursor.getColumnIndex(DatabaseContract.ShoeColumns.SHOE_NAME);
mCursor.moveToPosition(position);
final int id = mCursor.getInt(idIndex);
byte[] shoeImg = mCursor.getBlob(imgValue);
String brandNameStr = mCursor.getString(shoeBrandName);
String shoeNameStr = mCursor.getString(shoeName);
Bitmap bmp = BitmapFactory.decodeByteArray(shoeImg, 0, shoeImg.length);
holder.itemView.setTag(id);
holder.shoeImage.setImageBitmap(Bitmap.createScaledBitmap(bmp, 100, 100, false));
holder.shoeBrandName.setText(brandNameStr);
holder.shoeName.setText(shoeNameStr);
holder.getAdapterPosition();
CustomAdapter.shoeName = shoeNameStr;
CustomAdapter.brandName = brandNameStr;
CustomAdapter.byteArray = mCursor.getBlob(imgValue);
}
@Override
public int getItemCount() {
return (mCursor != null) ? mCursor.getCount() : 0;
}
public void swapCursor(Cursor cursor) {
if (mCursor != null) {
mCursor.close();
}
mCursor = cursor;
notifyDataSetChanged();
}
}
最后这是我的DetailsActivity（当点击了recyclerview项目时，这就是点击将带你去的地方）
package com.example.android.myshoecloset;
/*Assume appropriate imports*/
public class ClosetFragment extends Fragment implements LoaderManager.LoaderCallbacks<Cursor> {
private static final String TAG = "ClosetFragment";
protected RecyclerView mRecyclerView;
protected CustomAdapter mAdapter;
private static final int CUSTOM_LOADER_ID = 0;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_closet, container, false);
rootView.setTag(TAG);
mRecyclerView = (RecyclerView) rootView.findViewById(R.id.recyclerView);
mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity().getApplicationContext()));
mAdapter = new CustomAdapter(getActivity().getApplicationContext());
mRecyclerView.setAdapter(mAdapter);
getActivity().getSupportLoaderManager().initLoader(CUSTOM_LOADER_ID, null, this);
return rootView;
}
@Override
public void onResume()
{
super.onResume();
getActivity().getSupportLoaderManager().restartLoader(CUSTOM_LOADER_ID, null, this); }
@Override
public Loader<Cursor> onCreateLoader(int id, final Bundle loaderArgs) {
return new AsyncTaskLoader<Cursor>(getActivity().getApplicationContext()) {
Cursor mTaskData = null;
@Override
protected void onStartLoading()
{
if(mTaskData != null)
{
deliverResult(mTaskData);
}
else
{
forceLoad();
}
}
public Cursor loadInBackground()
{
try
{
return getActivity().getApplicationContext().getContentResolver().query(DatabaseContract.CONTENT_URI,
null,
null,
null,
null);
} catch(Exception e)
{
Log.e("", "Failed to asynchronously load data.");
e.printStackTrace();
return null;
}
}
public void deliverResult(Cursor data)
{
mTaskData = data;
super.deliverResult(data);
}
};
}
@Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data)
{
mAdapter.swapCursor(data);
}
@Override
public void onLoaderReset(Loader<Cursor> loader)
{
mAdapter.swapCursor(null);
}
}
谢谢！
答案 0 :(得分：0)
据我所知，您的代码的相关部分是您的视图持有者中的onClick方法：
@Override
public void onClick(View v) {
Intent i = new Intent(v.getContext(), ShoeDetailActivity.class);
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
v.getContext().startActivity(i);
}
详情活动中的onCreate方法：
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
...
byte[] b = getIntent().getByteArrayExtra("ImageBit");
...
brandShoe.setText(getIntent().getStringExtra("ShoeName"));
nameShoe.setText(getIntent().getStringExtra("BrandName"));
}
在细节活动中，您试图从意图附加信息中提取信息......但您从未提供过该信息。向观看者提供此信息需要重新考虑如何实现视图持有者本身。
我相信你应该能够使用viewholder的“适配器位置”在点击时从光标中获取必要的信息。也许是这样的：
@Override
public void onClick(View v) {
int position = getAdapterPosition();
mCursor.moveToPosition(position);
Intent i = new Intent(v.getContext(), ShoeDetailActivity.class);
i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
int imgValue = mCursor.getColumnIndex(DatabaseContract.ShoeColumns.SHOE_IMAGE);
int shoeBrandName = mCursor.getColumnIndex(DatabaseContract.ShoeColumns.SHOE_BRAND);
int shoeName = mCursor.getColumnIndex(DatabaseContract.ShoeColumns.SHOE_NAME);
i.putExtra("ImageBit", mCursor.getBlob(imgValue));
i.putExtra("ShoeName", mCursor.getString(shoeBrandName));
i.putExtra("BrandName", mCursor.getString(shoeName));
v.getContext().startActivity(i);
}
（请注意，"ShoeName"和"BrandName"似乎已被交换，但它们也会在您的详细信息活动中进行交换，因此我将其留给了他们。）
如果此getAdapterPosition() + mCursor方法不适合您，您始终可以在绑定时将必要信息传递给视图持有者，并在绑定时更新onClick()方法
如果这对您有用，请告诉我。如果没有，我们可以尝试从这里弄明白。