我计划CardView
在我的项目中包含一个。我已经RecyclerView
在我的项目中包含了卡片视图。问题是,我想为每张卡调用不同的活动。我为每张卡实现了不同的意图。但它需要我初始化数据。这是我的原始代码:
public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.ViewHolder> {
private Context context;
private String[] titles = {"Add new Research",
"View Your Research"};
private String[] details = {"Add your research files here",
"View all of your posted research"};
private int[] images = { R.drawable.add,
R.drawable.view};
class ViewHolder extends RecyclerView.ViewHolder{
public int currentItem;
public ImageView itemImage;
public TextView itemTitle;
public TextView itemDetail;
public ViewHolder(View itemView) {
super(itemView);
itemImage = (ImageView)itemView.findViewById(R.id.item_image);
itemTitle = (TextView)itemView.findViewById(R.id.item_title);
itemDetail =
(TextView)itemView.findViewById(R.id.item_detail);
itemView.setOnClickListener(new View.OnClickListener() {
@Override public void onClick(View v) {
int position = getAdapterPosition();
Intent intent = new Intent(context, Choose.class);
if(position==0){
intent = new Intent(context, AddFiles.class);
}else if(position==1){
intent = new Intent(context, ViewFiles.class);
}
context.startActivity(intent);
}
});
}
}
当我点击卡片视图时,它表明我的程序没有响应。
即使我将意图初始化为
Intent intent = null;
if(position==0){
intent = new Intent(context, AddFiles.class);
}else if(position==1){
intent = new Intent(context, ViewFiles.class);
}
context.startActivity(intent);
仍然有错误,我该怎么办?还是有更好的方法来做到这一点。这是我的 logcat 错误。
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.user.mcormpelo, PID: 3645
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Context.getPackageName()' on a null object reference
at android.content.ComponentName.<init>(ComponentName.java:128)
at android.content.Intent.<init>(Intent.java:4449)
at com.example.user.mcormpelo.RecyclerAdapter$ViewHolder$1.onClick(RecyclerAdapter.java:46)
at android.view.View.performClick(View.java:5198)
at android.view.View$PerformClick.run(View.java:21147)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)