这是一个完整的适配器代码
它显示错误NULL对象请解决请告诉如何错误删除...........
包com.softedge.visioneering.tfd.adapters;
import android.content.Context;
import android.content.Intent;
import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.TextView;
import com.softedge.visioneering.tfd.R;
import com.softedge.visioneering.tfd.fragments.Status_update_Fragment;
import com.softedge.visioneering.tfd.models.OrdersListModel;
import com.softedge.visioneering.tfd.utils.Status_update;
import java.util.List;
import static android.app.PendingIntent.getActivity;
/**
* Created by Atish Agrawal on 04-12-2016.
*/
public class MyOrdersAdapter extends RecyclerView.Adapter<MyOrdersAdapter.MyOrdersViewHolder> {
private List<OrdersListModel> list;
private Context context;
private LayoutInflater layoutInflater;
public MyOrdersAdapter(Context passedContext, List<OrdersListModel> passedModels) {
this.context = passedContext;
this.list = passedModels;
}
@Override
public MyOrdersViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View convertview = LayoutInflater.from(parent.getContext())
.inflate(R.layout.inner_list_orders, parent, false);
return new MyOrdersViewHolder(convertview);
}
@Override
public void onBindViewHolder(MyOrdersViewHolder holder, int position) {
holder.txtOrderDescription.setText("Title: " + list.get(position).getOrderTitle());
holder.txtOrderQuantity.setText("Order No.: " + list.get(position).getOrderNumber());
holder.txtOrderStatus.setText("Status: " + list.get(position).getOrderStatus());
holder.txtOrderDate.setText("Order Date: " + list.get(position).getOrderCreationDate());
holder.txtExpectedDate.setText("Exp. Date: " + list.get(position).getExpectedOrderCompletionDate());
holder.txtCreatedBy.setText("Assign to: " + list.get(position).getAssignToFirstName() + " " + list.get(position).getAssignToLastName());
holder.txtOrderStatus_Per.setText(list.get(position).getOrderStatusPercentage()+"%");
if(holder instanceof MyOrdersViewHolder) {
holder.update_btwn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
FragmentManager fragmentManager =getSupportFragmentManager();
//FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentManager.beginTransaction().add(R.id.cardViewStudentList, new Status_update_Fragment().newInstance()).addToBackStack("AddEvent").commit();
//fragmentTransaction.commit();
}
private FragmentManager getSupportFragmentManager() {
return null;
}
});
}
}
@Override
public int getItemCount() {
return list.size();
}
public class MyOrdersViewHolder extends RecyclerView.ViewHolder {
public TextView txtOrderDescription, txtOrderQuantity, txtOrderStatus, txtOrderDate, txtExpectedDate, txtCreatedBy,txtOrderStatus_Per;
public Button update_btwn;
public MyOrdersViewHolder(View convertView) {
super(convertView);
update_btwn=(Button) convertView.findViewById(R.id.status_update_button);
txtOrderDescription = (TextView) convertView.findViewById(R.id.txtOrderDescription);
txtOrderQuantity = (TextView) convertView.findViewById(R.id.txtOrderQuantity);
txtOrderStatus = (TextView) convertView.findViewById(R.id.txtOrderStatus);
txtOrderStatus_Per=(TextView)convertView.findViewById(R.id.txtOrder_Status_per);
txtOrderDate = (TextView) convertView.findViewById(R.id.txtOrderDate);
txtExpectedDate = (TextView) convertView.findViewById(R.id.txtExpectedDate);
txtCreatedBy = (TextView) convertView.findViewById(R.id.txtCreatedBy);
/*update_btwn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentManager.beginTransaction().add(R.id.cardViewStudentList, new Status_update_Fragment().newInstance()).addToBackStack("AddEvent").commit();
fragmentTransaction.commit();
}
private FragmentManager getSupportFragmentManager() {
return null;
}
});*/
}
}
}
代码是适配器代码： 鞋子错误，我尝试了很多次，但它没有解决。 我正在使用RecylerView显示文本。 在那里我放置了一个按钮，想要在Button Click上调用片段 请告诉我解决方案
这是我的JAVA API类从我称之为适配器类：
public class OrdersListAPI扩展了AsyncTask {
private static final String TAG = OrdersListAPI.class.getSimpleName();
private ProgressDialog progressDialog = null;
private String jsonString, response = "";
private OrdersListModel ordersListModel;
private RecyclerView recyclerViewOrders;
private List<OrdersListModel> ordersListModels;
private MyOrdersAdapter myOrdersAdapter;
private Context context;
/**
* @param callingContext Context of the calling activity
*/
public OrdersListAPI(Context callingContext, RecyclerView passedRecyclerViewOrders,
List<OrdersListModel> passedOrderListModels,
MyOrdersAdapter passedAdapter, String passedJSON) {
// Initializing the variables
this.context = callingContext;
this.recyclerViewOrders = passedRecyclerViewOrders;
this.myOrdersAdapter = passedAdapter;
this.ordersListModels = passedOrderListModels;
this.jsonString = passedJSON;
}
@Override
protected void onPreExecute() {
// Displaying a progressBar
super.onPreExecute();
progressDialog = new ProgressDialog(context);
progressDialog.setMessage("Please wait...");
progressDialog.setCancelable(false);
progressDialog.show();
}
/*
* (non-Javadoc)
*
* @see android.os.AsyncTask#doInBackground(Params[])
*/
@Override
protected Boolean doInBackground(Void... arg0) {
// Checking Internet connection
if (ProjectUtils.isConnectedToInternet(context)) {
// Connected to internet
try {
/**
* Preparing the URL of the Webserver API
*/
DefaultHttpClient client = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(ApplicationUtils.RECIEVED_ORDERS_LIST_API);
httpPost.setHeader("Accept", "application/json");
httpPost.setHeader("Content-type", "application/json");
/**
*
* Adding the JSON object to the HTTP-POST
*/
StringEntity entity = new StringEntity(jsonString.toString());
httpPost.setEntity(entity);
/**
* Making call to the server
*/
HttpResponse httpResponse = client.execute(httpPost);
/**
* Checking the response from the server
*/
int statusCode = httpResponse.getStatusLine().getStatusCode();
if (statusCode == HttpURLConnection.HTTP_OK || statusCode == HttpURLConnection.HTTP_CREATED) {
HttpEntity httpEntity = httpResponse.getEntity();
/**
* Fetching response from the server
*/
response = EntityUtils.toString(httpEntity);
if (ApplicationUtils.isLogEnabled)
Log.d(TAG, "Response: " + response.trim());
// Processing the response
JSONArray ordersArray = new JSONArray(response);
for (int i = 0; i < ordersArray.length(); i++) {
JSONObject orderJSONObject = ordersArray
.getJSONObject(i);
/**
* Initialising Orders Model
*/
ordersListModel = new OrdersListModel();
JSONObject order_det_JSONObject=orderJSONObject.getJSONObject(JSONUtils.EO_ORDER_DETAILS);
JSONObject assignToJSONObject = orderJSONObject.getJSONObject(JSONUtils.ASSIGNED_TO);
if (TextUtils.equals(assignToJSONObject.getString("primaryKey"),"11")) {
/**
* Fetching Order Details
*/
ordersListModel.setOrderTitle(order_det_JSONObject.getString(JSONUtils.ORDER_TITLE));
ordersListModel.setOrderNumber(order_det_JSONObject.getString(JSONUtils.ORDER_NUMBER));
ordersListModel.setOrderStatus(order_det_JSONObject.getString(JSONUtils.ORDER_STATUS));
ordersListModel.setOrderCreationDate(order_det_JSONObject.getString(JSONUtils.ORDER_CREATION_DATE));
ordersListModel.setExpectedOrderCompletionDate(order_det_JSONObject.getString(JSONUtils.EXPECTED_ORDER_COMPLETION_DATE));
ordersListModel.setOrderStatusPercentage(order_det_JSONObject.getString(JSONUtils.ORDER_STATUS_PERCENTAGE));
/**
* Fetching User Details
*/
//This Show Assign not Created_By
//JSONObject createdByJSONObject = orderJSONObject.getJSONObject(JSONUtils.ASSIGNED_TO);
ordersListModel.setAssignToFirstName(assignToJSONObject.getString(JSONUtils.FIRST_NAME));
ordersListModel.setAssignToLastName(assignToJSONObject.getString(JSONUtils.LAST_NAME));
ordersListModels.add(ordersListModel);
}
}
return true;
}
} catch (Exception e) {
e.printStackTrace();
}
}
return null;
}
@Override
protected void onPostExecute(Boolean result) {
// Moving to new activity and removing the progress dialog
super.onPostExecute(result);
if (progressDialog != null && progressDialog.isShowing())
progressDialog.dismiss();
// context.startActivity(new Intent(context, Dashboard.class));
//((Activity) context).finish();
if (result == null) {
// User not connected to internet
Toast.makeText(context, "No Internet connection",
Toast.LENGTH_SHORT).show();
return;
}
if (result) {
// Server returned true
/**
* Process Response
*/
myOrdersAdapter = new MyOrdersAdapter(context, ordersListModels);
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(context);
recyclerViewOrders.setLayoutManager(mLayoutManager);
recyclerViewOrders.setItemAnimator(new DefaultItemAnimator());
recyclerViewOrders.setAdapter(myOrdersAdapter);
myOrdersAdapter.notifyDataSetChanged();
}
}
}
这是一个JAVA API，它来自Load Recyler Adapter
答案 0 :(得分：1)
将listener代码移至onBindViewHolder()：
@Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
if(holder instanceof MyOrdersViewHolder) {
holder.update_btwn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentManager.beginTransaction().add(R.id.cardViewStudentList, new Status_update_Fragment().newInstance()).addToBackStack("AddEvent").commit();
fragmentTransaction.commit();
}
private FragmentManager getSupportFragmentManager() {
return null;
}
});
}
}
编辑，对于您的其他错误，我猜这个上下文是android.app.Activity，然后在导入android.app.Activity后在适配器中执行此操作：
((Activity)context).getSupportFragmentManager();
OR 只需使用您调用适配器的活动的类名：
((YOUR_ACTIVITY_NAME)context).getSupportFragmentManager();
而不是：getSupportFragmentManager();
答案 1 :(得分：0)
Solutions is :
final FragmentManager fragmentManager = ((FragmentActivity) context).getSupportFragmentManager();