我是Android开发的新手。在我的应用程序中,我使用 JSON 从 MySQL 数据库填充 RecyclerView,并创建了多个多个活动。应用程序在我的 PC 上的模拟器上运行流畅,但是当我尝试在我的 Android 手机上运行应用程序时,当我单击回收器视图中的任何项目时,它只是崩溃了。每个列表项都有多个文本视图和图像视图。我无法弄清楚出了什么问题。
根据我的轻描淡写,问题区域是:
holder.llCountryListItem.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//Toast.makeText(context, "You clicked on " + countId, Toast.LENGTH_SHORT).show();
Toast.makeText(context, "You clicked on " + context, Toast.LENGTH_SHORT).show();
Intent intent = new Intent(context, CountryDetails.class);
intent.putExtra("id", countId);
intent.putExtra("name", countryListItem.getName());
intent.putExtra("capital", countryListItem.getCapital());
intent.putExtra("continent", countryListItem.getContinent());
intent.putExtra("population", countryListItem.getPopulation());
context.startActivity(intent);
}
});
回收器适配器和支架的完整代码查看列表项:
public class CountryAdapter extends RecyclerView.Adapter<CountryAdapter.ViewHolder> {
private List<CountryListItem> countryListItems;
private Context context;
public CountryAdapter(List<CountryListItem> countryListItems, Context context) {
this.countryListItems = countryListItems;
this.context = context;
}
@Override
public CountryAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.country_list_item, parent, false);
return new ViewHolder(v);
}
@Override
public void onBindViewHolder(CountryAdapter.ViewHolder holder, int position) {
final CountryListItem countryListItem = countryListItems.get(position);
holder.textViewName.setText(countryListItem.getName());
holder.textViewCapital.setText(countryListItem.getCapital());
holder.textViewId.setText(countryListItem.getContinent() + "nPopulation: " + countryListItem.getPopulation() + " - GDP: " + countryListItem.getGdp());
final int countId;
countId = (Integer) countryListItem.getId();
Picasso.with(context)
.load(imageURL)
.into(holder.imCountry);
holder.llCountryListItem.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Toast.makeText(context, "You clicked on " + context, Toast.LENGTH_SHORT).show();
Intent intent = new Intent(context, CountryDetails.class);
intent.putExtra("id", countId);
intent.putExtra("name", countryListItem.getName());
intent.putExtra("capital", countryListItem.getCapital());
intent.putExtra("continent", countryListItem.getContinent());
intent.putExtra("population", countryListItem.getPopulation());
context.startActivity(intent);
}
});
}
@Override
public int getItemCount() {
return countryListItems.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
public TextView textViewId;
public TextView textViewName;
public TextView textViewCapital;
public ImageView imCountry;
public LinearLayout llCountryListItem;
public ViewHolder(View itemView) {
super(itemView);
textViewId = (TextView) itemView.findViewById(R.id.tvId);
textViewName = (TextView) itemView.findViewById(R.id.tvName);
textViewCapital = (TextView) itemView.findViewById(R.id.tvCapital);
imCountry = (ImageView) itemView.findViewById(R.id.imCountry);
llCountryListItem = (LinearLayout) itemView.findViewById(R.id.llCountryListItem);
}
}
}
我的列表项视图的 XML 是:
<?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="wrap_content"
android:layout_margin="0dp" >
<android.support.v7.widget.CardView
android:layout_margin="5dp"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:id="@+id/llCountryListItem"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:background="@android:color/holo_blue_dark"
android:padding="1dp">
<TextView
android:id="@+id/tvName"
android:text="Name"
android:textSize="16sp"
android:textStyle="bold"
android:textColor="#ffffff"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:padding="2dp"
android:background="@android:color/holo_blue_light">
<ImageView
android:id="@+id/imCountry"
android:layout_gravity="center"
android:layout_width="70dp"
android:layout_height="45dp" />
<LinearLayout
android:paddingLeft="@dimen/activity_horizontal_margin"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<TextView
android:id="@+id/tvCapital"
android:textSize="14sp"
android:textStyle="bold"
android:textColor="#efefef"
android:text="Capital"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
<TextView
android:id="@+id/tvId"
android:text="Asia, Population: 185,963,247"
android:textSize="12sp"
android:textColor="#fafafa"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
</android.support.v7.widget.CardView>
</LinearLayout>
似乎您传递给适配器的上下文可能是应用程序上下文。在这种情况下,请将此行添加到您的意图中
intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
或者确保上下文为活动类型 (YourActivity.this)。
此外,在适配器类中存储上下文不是一个好主意,这可能会导致潜在的内存泄漏。如果可能,在绑定视图时使用 view.getContext()。