问题
I have a fragment, which contains a recyclerview. This recyclerview is managed with an adapter that includes the viewholder pattern. In the fragment I have a "Save" button, this button must check that no TextInputEditText is empty in the list.
The problem is that I can not access the TextInputEditText of the adapter. ViewHolder is only accessible from the "onBindViewHolder" method. I tried to access from fragment in a way:
for (int i = 0; i < employeeList.size(); i++) {
View employeeView = recyclerEmployees.findViewHolderForAdapterPosition(i).itemView;
if (employeeView != null) {
TextInputLayout textInputLayoutName = employeeView.findViewById(R.id.tilName);
TextInputEditText textInputEditTextName = employeeView.findViewById(R.id.tieName);
By doing this I have managed to mark error in the TextInputLayout. I have also been able to get the text of the TextInputEditText. Everything seemed to work, but ...
The problem appears when the list changes and I need to refresh the adapter by calling notifyDataSetChanged
findViewHolderForAdapterPosition returns null in some positions of the list.
I read in some post that it is not safe to call that method https://stackoverflow.com/a/32840927/1484779
I have also read that it is not a good practice to access the viewholder outside the onBindViewHolder method.
Can anyone help me get this? It does not seem difficult but it is causing me a great waste of time.
I just want to click on my save button in the fragment and check that no TextInputEditText is empty in the list of items in my recyclerview
Thanks
回答1:
Try this
AddMoreAdapter
public class AddMoreAdapter extends RecyclerView.Adapter<AddMoreAdapter.ViewHolder> {
Context context;
ArrayList<AddMorePojo> arrayList;
public AddMoreAdapter(Context context, ArrayList<AddMorePojo> arrayList) {
this.context = context;
this.arrayList = arrayList;
}
@Override
public AddMoreAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.addmorelayout, parent, false);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(AddMoreAdapter.ViewHolder holder, int position) {
Log.e("VALUE ", arrayList.get(position).getUserName());
if (!TextUtils.isEmpty(arrayList.get(position).getUserName())) {
holder.edtName.setText(arrayList.get(position).getUserName());
}
if (!TextUtils.isEmpty(arrayList.get(position).getError())) {
holder.edtName.setError(arrayList.get(position).getError());
} else {
holder.edtName.setError(null);
}
}
@Override
public int getItemCount() {
return arrayList.size();
}
public ArrayList<AddMorePojo> getArrayList() {
return arrayList;
}
public class ViewHolder extends RecyclerView.ViewHolder {
EditText edtName;
public ViewHolder(View itemView) {
super(itemView);
edtName = itemView.findViewById(R.id.edtUname);
edtName.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
arrayList.get(getAdapterPosition()).setUserName(charSequence.toString());
}
@Override
public void afterTextChanged(Editable editable) {
}
});
}
}
}
AddMorePojo
public class AddMorePojo
{
String userName,error;
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getError() {
return error;
}
public void setError(String error) {
this.error = error;
}
}
MyActivity
public class MyActivity extends AppCompatActivity {
RecyclerView myRc;
ArrayList<AddMorePojo> arrayList = new ArrayList<>();
Button btnGetData;
AddMoreAdapter adapter;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my);
myRc = (RecyclerView) findViewById(R.id.myRc);
btnGetData = (Button) findViewById(R.id.btnGetData);
myRc.setHasFixedSize(true);
myRc.setLayoutManager(new LinearLayoutManager(this, LinearLayoutManager.VERTICAL, false));
AddMorePojo addMorePojo = new AddMorePojo();
addMorePojo.setUserName("");
arrayList.add(addMorePojo);
AddMorePojo addMorePojo1 = new AddMorePojo();
addMorePojo1.setUserName("");
addMorePojo1.setError("");
arrayList.add(addMorePojo1);
AddMorePojo addMorePojo2 = new AddMorePojo();
addMorePojo2.setUserName("");
addMorePojo2.setError("");
arrayList.add(addMorePojo2);
adapter = new AddMoreAdapter(this, arrayList);
myRc.setAdapter(adapter);
btnGetData.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
boolean flag=true;
ArrayList<AddMorePojo> pojoArrayList = adapter.getArrayList();
for (int i = 0; i < pojoArrayList.size(); i++) {
if (pojoArrayList.get(i).getUserName().isEmpty()) {
pojoArrayList.get(i).setError("Please enter userName");
flag=false;
}else {
// pojoArrayList.get(i).setError("");
}
}
adapter = new AddMoreAdapter(MyActivity.this, pojoArrayList);
myRc.setAdapter(adapter);
if (flag){
Toast.makeText(MyActivity.this, "Valid data", Toast.LENGTH_SHORT).show();
}else {
Toast.makeText(MyActivity.this, "Invalid data", Toast.LENGTH_SHORT).show();
}
}
});
}
}
layout.activity_my
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<android.support.v7.widget.RecyclerView
android:id="@+id/myRc"
android:layout_width="match_parent"
android:paddingBottom="50dp"
android:layout_height="match_parent" />
<Button
android:id="@+id/btnGetData"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="20dp"
android:gravity="center"
android:layout_alignParentBottom="true"
android:text="Get Data" />
</RelativeLayout>
addmorelayout
<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:cardElevation="10dp"
app:cardUseCompatPadding="true">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<EditText
android:id="@+id/edtUname"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Enter User Name" />
</LinearLayout>
</android.support.v7.widget.CardView>
回答2:
Yes you are right its not difficult.
@Override
public void onBindView(Object object, int pos) {
Employee employee = (Employee) object;
editText.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
employee.setName(charSequence.toString());
}
@Override
public void afterTextChanged(Editable editable) {
}
});
}
And on save button get value from list.
回答3:
You can use a boolean field in your model for example.
class TestData{
private boolean isTextEmpty;
private String textData;
public void setTextEmpty(boolean isTrue){
isTextEmpty = isTrue;
}
public boolean isTextEmpty(){
return isTextEmpty;
}
public void setTextData(String data){
textData = data;
}
public void getData(){
return textData;
}
........
///other fields goes here
}
now use this model in your list and fed it to adapter
public class TestAdapter extends RecyclerView.Adapter<TestAdapter.ViewHolder> {
ArrayList<TestData> arrayList;
boolean isSubmitClick = false;
public AddMoreAdapter(ArrayList<TestData> arrayList) {
this.arrayList = arrayList;
}
@Override
public TestAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.test_data_item, parent, false);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(TestAdapter.ViewHolder holder, int position) {
TestData data = arrayList.get(holder.getAdapterPosition());
if (holder.editText.getText().toString()==null) {
if(isSubmitClick){
holder.inputText.setError("please enter a valid input");
}
data.setTextEmpty(true);
} else {
data.setTextEmpty(false);
//do something else
}
}
@Override
public int getItemCount() {
return arrayList.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextInputLayout textInput;
EditText editName;
public ViewHolder(View itemView) {
super(itemView);
editName = itemView.findViewById(R.id.etTest);
textInput = itemView.findViewById(R.id.tilTest);
editName.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void afterTextChanged(Editable editable) {
arrayList.get(getAdapterPosition()).setTestData(editable.toString());
}
});
}
}
public void setSubmitClick(boolean isTrue){
this.isSubmitClick = isTrue;
}
}
now in your fragment do like this call adapter.setSubmitClick(true); on click of your button and then validate the data like below.
public void isDataValid(){
for(int i = 0; i<arrayList.size(); i++){
TestData data = arrayList.get(i);
if(data.isTextEmpty()){
adapter.notifyItemChanged(i);
return;
}
}
//do something here as all data is valid
callServer();
}
来源：https://stackoverflow.com/questions/51454613/how-can-i-validate-recyclerview-adapter-textinputedittext-from-fragment