如何从片段验证 recyclerview 适配器 TextInputEditText？

Question

我有一个片段，其中包含一个 recyclerview。这个 recyclerview 由一个包含 viewholder 模式的适配器管理。 在片段中我有一个“保存”按钮，此按钮必须检查列表中没有 TextInputEditText 为空。

问题是我无法访问适配器的 TextInputEditText。 ViewHolder 只能通过“onBindViewHolder”方法访问。 我尝试以某种方式从片段访问：

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);

通过这样做，我设法在 TextInputLayout 中标记错误。我还能够获取 TextInputEditText 的文本。一切似乎都正常，但是...

列表更改时出现问题，我需要通过调用notifyDataSetChanged刷新适配器

findViewHolderForAdapterPosition 在列表的某些位置返回 null。

我在一些帖子中读到调用该方法是不安全的 https://stackoverflow.com/a/32840927/1484779

我还了解到，在 onBindViewHolder 方法之外访问 viewholder 不是一个好习惯。

谁能帮我搞定这个？这似乎并不难，但它让我浪费了很多时间。

我只想单击片段中的保存按钮并检查recyclerview 中的项目列表中的TextInputEditText 是否为空

谢谢

Answer 1

试试这个

添加更多适配器

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) {

                }
            });


        }
    }
}

添加更多Pojo

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;
    }
}

我的活动

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>

添加更多布局

<?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>

Answer 2

是的，你是对的，这并不难。

@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) {

            }
        });
    }

并在保存按钮上从列表中获取值。

Answer 3

例如，您可以在模型中使用布尔字段。

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
}

现在在您的列表中使用此模型并将其提供给适配器

    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; 
        }

}

现在在您的片段中，点击您的按钮，像这样调用adapter.setSubmitClick(true);，然后像下面那样验证数据。

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();
}