I have a class to take data from a database and every time I create a variable in the debug mode the name of the variable appears with the message 'this' is not available and I cannot save any type of data in it.
public class DatosPerfilUsuario {
RequestQueue requestQueue;
SharedPreferencias sharedPreferencias = new SharedPreferencias();
String[] StringSplit;
public void RetirarPerfilUsuario(final Context context, final ImageView imageView, final EditText nombre, final EditText nombreusuario, final EditText sexo, final EditText edad, final EditText email, final EditText bio){
StringRequest getRequest = new StringRequest(Request.Method.POST, DatosBase.CONEXION_DB_RETIRAR_PERFILUSUARIO, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
if(response.equals("0")){
}else {
StringSplit = response.split("/");
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
}
}) {
protected Map<String,String> getParams(){
Map<String, String> params = new HashMap<String, String>();
params.put("NombreUsuario",sharedPreferencias.obtenerValorString(context,"Usuario").toLowerCase());
return params;
}
};
requestQueue = Volley.newRequestQueue(context);
requestQueue.add(getRequest);
}
Code
This situation happens to me with each type of variable that I create int, string, bool ...
I have different classes that do the same, but the problem only arises in this.
I have looked for a solution to the problem in google but there is very little information about this problem, if someone has the solution or understands why this problem is due I would appreciate your help.
UPDATED
It looks like this is not preventing you from compiling and running the code, only that you can't view the variable's contents in the debug window. Sorry. This is not uncommon. The debugger can't determine the this in the current context.
It looks like you may be using Android Studio? If so, check this: https://stackoverflow.com/a/37273436/12431728
OLD / WRONG
Your Response.Listener<String> is an anonymous class, so this refers to the anonymous class. Since StringSplit is a field of the outer class, you should be able to access it as:
OuterClassName.this.StringSplit = ...
Where OuterClassName is the name of the class that contains this code (and StringSplit).
Related
How to create field variable automatically when I create method used that field. I've create template like this:
void $METHOD_NAME$() {
$FIELD_NAME$ = true;
}
when I type field name (e.g. mState) in method will create field as:
private boolean mState = false;
Hope someone help. Sorry my bad.
Given the screenshot of your template, you can also create a field with the following live template:
private boolean $param$ = false;
#Override
public void onBackPressed() {
if ($param$) super.onBackPressed();
android.widget.Toast.makeText(this, "$message$",
android.widget.Toast.LENGTH_SHORT).show();
$param$ = true;
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
$param$ = false;
}
}, 100);
}
Where $param$ and $message$ are regular variables without anything special.
However, like I said in the comment on your question, I suggest to split it up in several smaller templates.
Consider to split it up in:
field + method with just:
private boolean $param$ = false;
#Override
public void onBackPressed() {
if ($param$) super.onBackPressed();
$param$ = true;
}
Then create a template for the message:
android.widget.Toast.makeText(this, "$message$", android.widget.Toast.LENGTH_SHORT).show();
And last but not least, create a template for the postDelayed:
final Handler handler = new Handler();
handler.postDelayed(new Runnable() {
#Override
public void run() {
$END$
}
}, $delay$);
Note: the $delay$ as a bonus you can even give it a default value or create a list of predefined values for ease of use.
Note2: Instead of $param$ = false; I've replaced it with $END$. This will position your cursor here once you've selected the delay. Now you can type mState = false manually here, or whatever code you need in the context at that moment. This makes the template much more flexible and easier to use.
PS. I suppose you want to call super.onBackPressed() only when the value is false (on the first invocation). In that case use if (!$param$) instead.
// Update:
In order to group the newly added field with the other fields and not halfway somewhere in your class between other methods, rearrange the code
via the menu with: Code -> rearrange code.
To customise this, check your arrangement settings under: settings -> code style -> <language> -> arrangement
public static class SimpleItemRecyclerViewAdapter
extends RecyclerView.Adapter<SimpleItemRecyclerViewAdapter.ViewHolder> {
private final ItemListActivity mParentActivity;
private final List<DummyContent.DummyItem> mValues;
private final boolean mTwoPane;
private final View.OnClickListener mOnClickListener = new View.OnClickListener() {
#Override
public void onClick(View view) {
DummyContent.DummyItem item = (DummyContent.DummyItem) view.getTag();
if (mTwoPane) {
Bundle arguments = new Bundle();
arguments.putString(WebpageDetailFragment.ARG_ITEM_ID, item.id);
WebpageDetailFragment fragment = new WebpageDetailFragment();
fragment.setArguments(arguments);
mParentActivity.getSupportFragmentManager().beginTransaction()
.replace(R.id.webpage_detail_container, fragment)
.commit();
This happens when you change the default item names during the wizard of creating the activity.
just rename the ItemListActivity to the name of your Activity . ( the name of the file that has that code error).
use refactor rename to change it everywhere it's mentioned.
If the ItemListActivity (or whatever you ended up calling it) extends from Activity and not AppCompatActivity then try changing the line
mParentActivity.getSupportFragmentManager().beginTransaction()
to
mParentActivity.getFragmentManager().beginTransaction()
My CardView duplicate elements upon data change, the vardView is within a tab, and the way i declared that tab fragment as following;
in the onCreateView, i declared all the necessary firebase links and value events listeners to retrieve the required data related to the elements displayed on the cards.
ref.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot snapshot) {
if(snapshot !=null){
for (DataSnapshot child: snapshot.getChildren()) {
Log.i("MyTag", child.getValue().toString());
imagesfeedsList.add(child.child("address").getValue(String.class));
authorfeedsList.add(child.child("author").getValue(String.class));
ratingfeedsList.add(child.child("rating").getValue(String.class));
locationfeedsList.add(child.child("location").getValue(String.class));
publicIDfeedsList.add(child.child("public_id").getValue(String.class));
}
Log.i("MyTag_imagesDirFinal", imagesfeedsList.toString());
mImages = imagesfeedsList.toArray(new String[imagesfeedsList.size()]);
author = authorfeedsList.toArray(new String[authorfeedsList.size()]);
ratingV = ratingfeedsList.toArray(new String[ratingfeedsList.size()]);
locationV = locationfeedsList.toArray(new String[locationfeedsList.size()]);
publicID = publicIDfeedsList.toArray(new String[publicIDfeedsList.size()]);
numbOfAdrs = Long.valueOf(imagesfeedsList.size());
LENGTH = Integer.valueOf(String.valueOf(numbOfAdrs));
}
right after the snippet the adapter setup;
ContentAdapter adapter = new ContentAdapter(recyclerView.getContext());
recyclerView.setAdapter(adapter);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
return recyclerView;
}
Then comes the view holder with a RecycleView, declaring the cardView elements. One of the elements is a ratingBar, and here where the ratingbar Listener is to submit the user rating on a specific picture.
after that the content adapter;
public static class ContentAdapter extends RecyclerView.Adapter<ViewHolder> {
// Set numbers of List in RecyclerView.
private Context mContext;
public ContentAdapter(Context context) {
this.mContext = context;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
return new ViewHolder(LayoutInflater.from(parent.getContext()), parent);
}
#Override
public void onBindViewHolder(final ViewHolder holder, int position) {
holder.authorName.setText(author[position]);
holder.ratingValue.setText(ratingV[position]);
holder.locationValue.setText(locationV[position]);
Picasso.with(mContext).load(mImages[position]).into(holder.picture);
#Override
public int getItemCount() {
return LENGTH;
}
}
My problem is whenever the user submits a rating or even when the data related to any of the elements on anycard changes, the view gets duplicated ( i mean by the view, the cards ), a repetition of the cards, with the new data chnages displayed ?
i a not sure what is in my above code structure causing this and how to fix this repetitions, i mean i need the cards to be updated with the new data but not duplicated?
All right, so the problem was that every time the data changes, in the onCreate the imagesFeedList, ratingFeedList, etc does not get rid of the old information stored in it from the initial build, so when the refresh happens triggered by onDataChange, the new information gets added to the previous information, which cause the view to repeat the cards, thus just at the beginning of onDataChange and before storing any information in the several feedLists, it must be cleared;
imagesfeedsList.clear();
authorfeedsList.clear();
ratingfeedsList.clear();
locationfeedsList.clear();
publicIDfeedsList.clear();
and by that i made sure the view does not repeat build up based on old information.
I want to use RazorEngine to generate some html files. It's easy to generate strings first, then write them to files. But if the generated strings are too large, that will cause memory issues.
So I wonder is there a non-cached way to use RazorEngine, like using StreamWriter as its output rather than a string.
I google this for a while, but with no luck.
I think use a custom base template should be the right way, but the documents are so few(even out of date) on the offcial homepage of RazorEngine.
Any hint will be helpful!
OK. I figured it out.
Create a class that inherits TemplateBase<T>, and take a TextWrite parameter in the constructor.
public class TextWriterTemplate<T> : TemplateBase<T>
{
private readonly TextWriter _tw;
public TextWriterTemplate(TextWriter tw)
{
_tw = tw;
}
// override Write and WriteLiteral methods, write text using the TextWriter.
public override void Write(object value)
{
_tw.Write(value);
}
public override void WriteLiteral(string literal)
{
_tw.Write(literal);
}
}
Then use the template as this:
private static void Main(string[] args)
{
using (var sw = new StreamWriter(#"output.txt"))
{
var config = new FluentTemplateServiceConfiguration(c =>
c.WithBaseTemplateType(typeof(TextWriterTemplate<>))
.ActivateUsing(context => (ITemplate)Activator.CreateInstance(context.TemplateType, sw))
);
using (var service = new TemplateService(config))
{
service.Parse("Hello #Model.Name", new {Name = "Waku"}, null, null);
}
}
}
The content of output.txt should be Hello WAKU.
As I'm learning the new world of JavaFX2 I stumbled on another annoying problem. I'm developing a program with multiple scenes (~10 scenes). For that I created a small class like this:
public class SceneSelector {
...
public void setScene(Stage stage, String fxmlfilename, ObservableList ol) throws Exception{
String s = "../" + fxmlfilename;
Parent root = FXMLLoader.load(getClass().getResource(s));
root.setUserData(ol);
Scene scene = new Scene(root);
stage.setScene(scene);
//show the stage
stage.show();
}
}
This class works good enough for switching between the scenes.
Now the problem is that I sometimes need to pass data from Scene1 to Scene2. I'm trying to do this by setting the setUserData() for the new scene which basicly works exept for one thing. How can I get the userdata when the new Scene is beeing initialized? (because the Nodes are still null at that time)
Code at scene1:
//Code connected to a button that opens the new Scene
private void openLabID(ActionEvent event) throws Exception {
final Stage primaryStage = (Stage) btnNewScene.getScene().getWindow();
ObservableList<Koe> olAfTeWerkenKoeien = DA_Koe.getAfTeWerkenKoeien();
ss.setScene(primaryStage, "GUI/scenes/koe/Koe.fxml", olAfTeWerkenKoeien);
}
Code at scene2:
public void initialize(URL url, ResourceBundle rb) {
Scene s = lbl.getScene();
ObservableList<Koe> olAfTeWerkenKoeien = (ObservableList<Koe>) s.getRoot().getUserData();
System.out.println(olAfTeWerkenKoeien.size());
}
Of course Scene s gives a null value at this point (because lbl is null at this point), so I wonder, is there a method that is beeing fired right after initialize?
When I attach this code to a button on Scene2, it works like a charm, but it should be loaded automatically.
EDIT:
The setting of the data with the setMyData() method is not a problem, however retrieving it is:
public ObservableList<Koe> getMyData() {
return this.myData;
}
How can I get the CustomScene object when a controller initializes? Because doing this below will result in a NullPointerException (because btnSluiten is not initialized just yet):
#Override
public void initialize(URL url, ResourceBundle rb) {
...
Stage stage = (Stage) btnSluiten.getScene().getWindow();
CustomScene cs = (CustomScene) stage.getScene();
ObservableList<Koe> olKoe = cs.getMyData();
System.out.println(olKoe.size());
}
I believe you missed the point within the Scene object. From the Scene class documentation we can see that:
The JavaFX Scene class is the container for all content in a scene graph.
Which means that the Scene object is just a container and as such it's not supposed to hold any data.
With that in mind, you can make another static object with a field such as
private static Label lbl;
...
public static Label getLbl()
{
return MyStaticObject.Lbl;
}
...
and use it to store your lbl (or whatever object suits your information) and then statically retrieve it.
I'm doing that to set the owner of my other Stage objects from my application. I hope it helps. Cheers
If you really want your scene to be meaningful (aka store specific user data) you can extend it:
public class FooScene extends Scene {
private ObservableList myData;
public setMyData(ObservableList data) {
this.myData = data;
//handle data
}
}
The easiest way to make sure setup code is called after scene initialized it to call it by yourself:
public class SceneSelector {
...
public void setScene(Stage stage, String fxmlfilename, ObservableList ol) throws Exception{
String s = "../" + fxmlfilename;
Parent root = FXMLLoader.load(getClass().getResource(s));
// first: add root to scene
FooScene scene = new FooScene(root);
// second: apply data to scene (or root)
scene.setMyData(ol);
stage.setScene(scene);
//show the stage
stage.show();
}
}
You can use controller for scenes and pass the data through controller:
String filePath1 = "../" + fxmlfilename;
URL location1 = YourController1.class.getResource(filePath1);
FXMLLoader fxmlLoader = new FXMLLoader();
fxmlLoader.setLocation(location1);
fxmlLoader.setBuilderFactory(new JavaFXBuilderFactory());
Parent root = (Node) fxmlLoader.load(location1.openStream());
YourController1 ctrl1 = (YourController1) fxmlLoader.getController();
Then you can assign data to the controller:
ctrl1.setUserData();
Finally, just show the scene as you want:
Scene scene = new Scene(root);
stage.setScene(scene);
//show the stage
stage.show();
In the initialize() method in the controller, just get data from controller as usual data object.
Some Addition of #Sergey Grinev :
Create A custom Scene :
package sample;
import javafx.scene.Parent;
import javafx.scene.Scene;
public class DataPassingScene extends Scene {
public DataPassingScene(Parent parent) {
super(parent);
}
String tafsir;
public String getTafsir() {
return tafsir;
}
public void setTafsir(String tafsir) {
this.tafsir = tafsir;
}
}
Suppose your Main Class Name is App.java, Then Create a method to show new Stage :
public static void showLayout (Stage primaryStage, String fxmlFileName, String stringData) throws IOException {
Parent root = FXMLLoader.load(Objects.requireNonNull(App.class.getClassLoader().getResource(fxmlFileName)));
DataPassingScene scene = new DataPassingScene(root);
scene.setTafsir(stringData); // Here we pass the data
primaryStage.setScene(scene);
primaryStage.show();
}
Now When you want to pass the Data, Call the above method from any Where / any class in your app with some Data :
String tafsir = "This My Data" ;
try {
App.showLayout(new Stage(), "showTafsirFxml.fxml",tafsir);
} catch (IOException e) {
e.printStackTrace();
}
Then Get the data in your controller. To get the scene you have to get the stage, and to get the stage you have use one of your elements of FXML, suppose here your element is a button, called closeButton, So :
#FXML
private Button closeButton;
#Override
public void initialize(URL url, ResourceBundle rb) {
Platform.runLater(new Runnable() {
#Override public void run() {
Stage stage = (Stage) closeButton.getScene().getWindow();
DataPassingScene scene = (DataPassingScene) stage.getScene();
String s = scene.getTafsir(); // Here we get the Data
if(s!=null)
System.out.println("This is Tafsir From Highlight Table: "+s);
else
System.out.println("Data Passing Null");
}});
}
because, You have to wait some Times in above runLater, because for initializing scene take some time. Other wise scene will be null.