动态在 Android Studio 的 RecyclerView 中显示按钮。

huangapple
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英文:

Display buttons dynamically in recyclerview android studio

问题

  1. 我正在开发一个学生追踪应用程序，尝试在每个学生下方显示动态按钮。我将在下面粘贴一个图片，展示我希望它看起来的样子。
英文:

I am working on a student tracker app and I am trying to display dynamic buttons that get created under each of my students. I will paste an image below of what I hope for it to look like.

动态在 Android Studio 的 RecyclerView 中显示按钮。

At the moment, I am hardcoding the buttons for the first image. I am getting the picture of the student and their name from my firbase db. Now my questions is how can I generate the checkBox for each of the student's and make sure it's directly under their picture and name like above.

In my mind, I am thinking the algorithm would be something like

  1. Loop through my Students ArrayList
  2. Generate the checkBox for each student
  3. Place them onto my recyclerView.

I will paste relevant code down below.

daily_grading.xml

  1. <?xml version="1.0" encoding="utf-8"?>
  2. <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
  3.     xmlns:app="http://schemas.android.com/apk/res-auto"
  4.     xmlns:tools="http://schemas.android.com/tools"
  5.     android:layout_width="match_parent"
  6.     android:layout_height="match_parent"
  7.     tools:context=".DailyGrading">
  9.     <androidx.recyclerview.widget.RecyclerView
  10.         android:id="@+id/recyclerView"
  11.         android:layout_width="409dp"
  12.         android:layout_height="729dp"
  13.         app:layout_constraintEnd_toEndOf="parent"
  14.         app:layout_constraintStart_toStartOf="parent"
  15.         app:layout_constraintTop_toTopOf="parent" />
  17.     <CheckBox
  18.         android:id="@+id/checkBox"
  19.         android:layout_width="wrap_content"
  20.         android:layout_height="wrap_content"
  21.         android:text="PASS"
  22.         app:layout_constraintBottom_toBottomOf="parent"
  23.         app:layout_constraintEnd_toEndOf="@+id/recyclerView"
  24.         app:layout_constraintHorizontal_bias="0.046"
  25.         app:layout_constraintStart_toStartOf="parent"
  26.         app:layout_constraintTop_toTopOf="parent"
  27.         app:layout_constraintVertical_bias="0.499" />
  29.     <CheckBox
  30.         android:id="@+id/checkBox2"
  31.         android:layout_width="wrap_content"
  32.         android:layout_height="wrap_content"
  33.         android:text="FAIL"
  34.         app:layout_constraintBottom_toBottomOf="parent"
  35.         app:layout_constraintEnd_toEndOf="parent"
  36.         app:layout_constraintHorizontal_bias="0.261"
  37.         app:layout_constraintStart_toStartOf="parent"
  38.         app:layout_constraintTop_toTopOf="parent"
  39.         app:layout_constraintVertical_bias="0.499" />
  41. </androidx.constraintlayout.widget.ConstraintLayout>

student_item.xml

  1.  <?xml version="1.0" encoding="utf-8"?>
  2.     <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
  3.         xmlns:app="http://schemas.android.com/apk/res-auto"
  4.         xmlns:tools="http://schemas.android.com/tools"
  5.         android:layout_width="match_parent"
  6.         android:layout_height="wrap_content">
  7.     
  8.     
  9.         <androidx.cardview.widget.CardView
  10.             android:layout_width="match_parent"
  11.             android:layout_height="wrap_content"
  12.             android:layout_marginTop="50dp"
  13.             android:foreground="?android:attr/selectableItemBackground"
  14.             app:cardElevation="2dp"
  15.             app:layout_constraintEnd_toEndOf="parent"
  16.             app:layout_constraintStart_toStartOf="parent"
  17.             app:layout_constraintTop_toTopOf="parent">
  18.     
  19.         </androidx.cardview.widget.CardView>
  20.     
  21.         <RelativeLayout
  22.             android:id="@+id/relativeLayout2"
  23.             android:layout_width="match_parent"
  24.             android:layout_height="match_parent"
  25.             android:padding="5dp"
  26.     
  27.             tools:layout_editor_absoluteX="0dp"
  28.             tools:layout_editor_absoluteY="52dp">
  29.     
  30.             <ImageView
  31.                 android:id="@+id/imageView"
  32.                 android:layout_width="match_parent"
  33.                 android:layout_height="200dp"
  34.                 android:layout_marginTop="50dp"
  35.                 android:paddingTop="20dp"
  36.                 android:scaleType="centerCrop" />
  37.     
  38.             <TextView
  39.                 android:id="@+id/textView"
  40.                 android:layout_width="wrap_content"
  41.                 android:layout_height="wrap_content"
  42.                 android:layout_below="@+id/imageView"
  43.                 android:layout_margin="10dp"
  44.                 android:textSize="16sp" />
  45.     
  46.         </RelativeLayout>
  47.     
  48.     </androidx.constraintlayout.widget.ConstraintLayout>

DailyGrading.class

  1. public class DailyGrading extends AppCompatActivity{
  3.     RecyclerView recyclerView;
  4.     Button addStudent;
  7.     private DatabaseReference myRef;
  9.     public ArrayList<Students> students;
  10.     private RecyclerAdapter recyclerAdapter;
  11.     private Button orderStudents;
  13.     private EditText mEditTextAge;
  14.     private EditText mEditTextAssignment;
  15.     @Override
  16.     protected void onCreate(Bundle savedInstanceState) {
  17.         super.onCreate(savedInstanceState);
  18.         setContentView(R.layout.daily_grading);
  21.         recyclerView = findViewById(R.id.recyclerView);
  22.         addStudent = findViewById(R.id.addStudentButton);
  23.         mEditTextAge = findViewById(R.id.EditTextAge);
  24.         mEditTextAssignment = findViewById(R.id.EditTextAssignment);
  26.         recyclerView.setLayoutManager(new GridLayoutManager(this, 2));
  27.         recyclerView.setHasFixedSize(true);
  29.         myRef = FirebaseDatabase.getInstance().getReference();
  31.         students = new ArrayList<>();
  33.         ClearAll();
  35.         GetDataFromFirebase();
  39.     }
  40.     // fetches images and name from firebase
  41.     private void GetDataFromFirebase() {
  42.         Query query = myRef.child("student");
  44.         query.addValueEventListener(new ValueEventListener() {
  45.             @Override
  46.             public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
  47.                 ClearAll();
  48.                 for(DataSnapshot snapshot: dataSnapshot.getChildren()) {
  49.                     Students student = new Students();
  50.                     if (snapshot.child("url").getValue() == null) {
  51.                         student.setImageUrl(snapshot.child("imageUrl").getValue().toString());
  52.                     }
  53.                     else {
  54.                         student.setImageUrl(snapshot.child("url").getValue().toString());
  56.                     }
  57.                     student.setName(snapshot.child("name").getValue().toString());
  58.                     students.add(student);
  59.                 }
  60.                 recyclerAdapter = new RecyclerAdapter(getApplicationContext(), students);
  61.                 recyclerView.setAdapter(recyclerAdapter);
  62.                 recyclerAdapter.notifyDataSetChanged();
  63.             }
  65.             @Override
  66.             public void onCancelled(@NonNull DatabaseError databaseError) {
  68.             }
  69.         });
  70.     }
  71.     // will clear recyclerAdapter
  72.     private void ClearAll() {
  73.         if (students != null) {
  74.             students.clear();
  76.             if(recyclerAdapter != null) {
  77.                 recyclerAdapter.notifyDataSetChanged();
  78.             }
  79.         }
  80.         students = new ArrayList<>();
  81.     }
  83.     // method to generate checkboxes dynamically
  84.     public void generateButtonsDynamically() {
  85.         for(int i = 0; i < students.size(); i++){
  86.         }
  87.     }

RecyclerAdapter.class

  1. package com.example.studenttracker;
  3. import android.content.Context;
  4. import android.view.LayoutInflater;
  5. import android.view.View;
  6. import android.widget.ImageView;
  7. import android.view.ViewGroup;
  8. import android.widget.ImageView;
  9. import android.widget.TextView;
  11. import androidx.annotation.NonNull;
  12. import androidx.recyclerview.widget.RecyclerView;
  14. import com.bumptech.glide.Glide;
  16. import java.util.ArrayList;
  18. public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.ViewHolder> {
  19.     private OnItemClickListener mListener;
  20.     public interface OnItemClickListener {
  21.         void onItemClick(int position);
  22.     }
  23.     public void setOnItemClickListener(OnItemClickListener listener) {
  24.         mListener = listener;
  25.     }
  26.     private static final String Tag = "RecyclerView";
  27.     private Context mContext;
  28.     private ArrayList<Students> studentsArrayList;
  30.     public RecyclerAdapter(Context mContext, ArrayList<Students> studentsArrayList) {
  31.         this.mContext = mContext;
  32.         this.studentsArrayList = studentsArrayList;
  33.     }
  35.     @NonNull
  36.     @Override
  37.     public RecyclerAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
  38.         View view = LayoutInflater.from(parent.getContext())
  39.                 .inflate(R.layout.student_item,parent,false);
  40.         return new ViewHolder(view);
  42.     }
  44.     @Override
  45.     public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
  46.         //TextView
  47.         holder.textView.setText(studentsArrayList.get(position).getName());
  49.         Glide.with(mContext).load(studentsArrayList.get(position).getImageUrl()).into(holder.imageView);
  51.     }
  53.     @Override
  54.     public int getItemCount() {
  55.         return studentsArrayList.size();
  56.     }
  58.     public class ViewHolder extends RecyclerView.ViewHolder {
  59.         ImageView imageView;
  60.         TextView textView;
  62.         public ViewHolder(@NonNull View itemView) {
  63.             super(itemView);
  65.             imageView = itemView.findViewById(R.id.imageView);
  66.             textView = itemView.findViewById(R.id.textView);
  67.             itemView.setOnClickListener(new View.OnClickListener() {
  68.                 @Override
  69.                 public void onClick(View v) {
  70.                     if (mListener != null) {
  71.                         int position = getAdapterPosition();
  72.                         
  73.                     }
  74.                 }
  75.             });
  76.         }
  77.     }
  78. }

答案1

得分: 1

在 student_item.xml 而非 daily_grading.xml 中添加复选框。

英文:

Add Check Boxes in student_item.xml instead daily_grading.xml

答案2

得分: 1

请尝试以下代码：

  1. <CheckBox
  2.     android:id="@+id/checkBox"
  3.     android:layout_width="wrap_content"
  4.     android:layout_height="wrap_content"
  5.     android:text="PASS"
  6.     app:layout_constraintBottom_toBottomOf="parent"
  7.     app:layout_constraintEnd_toEndOf="@+id/recyclerView"
  8.     app:layout_constraintHorizontal_bias="0.046"
  9.     app:layout_constraintStart_toStartOf="parent"
  10.     app:layout_constraintTop_toTopOf="parent"
  11.     app:layout_constraintVertical_bias="0.499"
  12.     android:visibility="gone" />
  14. <CheckBox
  15.     android:id="@+id/checkBox2"
  16.     android:layout_width="wrap_content"
  17.     android:layout_height="wrap_content"
  18.     android:text="FAIL"
  19.     app:layout_constraintBottom_toBottomOf="parent"
  20.     app:layout_constraintEnd_toEndOf="parent"
  21.     app:layout_constraintHorizontal_bias="0.261"
  22.     app:layout_constraintStart_toStartOf="parent"
  23.     app:layout_constraintTop_toTopOf="parent"
  24.     app:layout_constraintVertical_bias="0.499"
  25.     android:visibility="gone" />
  1. @Override
  2. public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
  3.     //TextView
  4.     holder.textView.setText(studentsArrayList.get(position).getName());
  6.     Glide.with(mContext).load(studentsArrayList.get(position).getImageUrl()).into(holder.imageView);
  8.     if (studentsArrayList.get(position).displayButtons()) { //check if you need the buttons or not
  9.         holder.checkBox.setVisibility(View.VISIBLE);
  10.         holder.checkBox2.setVisibility(View.VISIBLE);
  11.     } else {
  12.         holder.checkBox.setVisibility(View.GONE);
  13.         holder.checkBox2.setVisibility(View.GONE);
  14.     }
  15. }
英文:

Try this:

  1. &lt;CheckBox
  2.         android:id=&quot;@+id/checkBox&quot;
  3.         android:layout_width=&quot;wrap_content&quot;
  4.         android:layout_height=&quot;wrap_content&quot;
  5.         android:text=&quot;PASS&quot;
  6.         app:layout_constraintBottom_toBottomOf=&quot;parent&quot;
  7.         app:layout_constraintEnd_toEndOf=&quot;@+id/recyclerView&quot;
  8.         app:layout_constraintHorizontal_bias=&quot;0.046&quot;
  9.         app:layout_constraintStart_toStartOf=&quot;parent&quot;
  10.         app:layout_constraintTop_toTopOf=&quot;parent&quot;
  11.         app:layout_constraintVertical_bias=&quot;0.499&quot;
  12.         android:visibility=&quot;gone&quot; /&gt;
  14.     &lt;CheckBox
  15.         android:id=&quot;@+id/checkBox2&quot;
  16.         android:layout_width=&quot;wrap_content&quot;
  17.         android:layout_height=&quot;wrap_content&quot;
  18.         android:text=&quot;FAIL&quot;
  19.         app:layout_constraintBottom_toBottomOf=&quot;parent&quot;
  20.         app:layout_constraintEnd_toEndOf=&quot;parent&quot;
  21.         app:layout_constraintHorizontal_bias=&quot;0.261&quot;
  22.         app:layout_constraintStart_toStartOf=&quot;parent&quot;
  23.         app:layout_constraintTop_toTopOf=&quot;parent&quot;
  24.         app:layout_constraintVertical_bias=&quot;0.499&quot;
  25.         android:visibility=&quot;gone&quot; /&gt;

and

  1. @Override
  2. public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
  3.     //TextView
  4.     holder.textView.setText(studentsArrayList.get(position).getName());
  6.     Glide.with(mContext).load(studentsArrayList.get(position).getImageUrl()).into(holder.imageView);
  8.     if (studentsArrayList.get(position).displayButtons()) { //check if you need the buttons or not
  9.         holder.checkBox.setVisibility(View.VISIBLE);
  10.         holder.checkBox2.setVisibility(View.VISIBLE);
  11.     } else {
  12.         holder.checkBox.setVisibility(View.GONE);
  13.         holder.checkBox2.setVisibility(View.GONE);
  14.     }
  15. }

答案3

得分: 1

把你的 student_item.xml 代码改成这样：

  1. <?xml version="1.0" encoding="utf-8"?>
  2. <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
  3.     xmlns:app="http://schemas.android.com/apk/res-auto"
  4.     xmlns:tools="http://schemas.android.com/tools"
  5.     android:layout_width="match_parent"
  6.     android:layout_height="wrap_content">
  8.     <androidx.cardview.widget.CardView
  9.         android:layout_width="match_parent"
  10.         android:layout_height="wrap_content"
  11.         android:layout_marginTop="50dp"
  12.         android:foreground="?android:attr/selectableItemBackground"
  13.         app:cardElevation="2dp"
  14.         app:layout_constraintEnd_toEndOf="parent"
  15.         app:layout_constraintStart_toStartOf="parent"
  16.         app:layout_constraintTop_toTopOf="parent">
  18.     </androidx.cardview.widget.CardView>
  20.     <RelativeLayout
  21.         android:id="@+id/relativeLayout2"
  22.         android:layout_width="match_parent"
  23.         android:layout_height="match_parent"
  24.         android:padding="5dp"
  26.         tools:layout_editor_absoluteX="0dp"
  27.         tools:layout_editor_absoluteY="52dp">
  29.         <ImageView
  30.             android:id="@+id/imageView"
  31.             android:layout_width="match_parent"
  32.             android:layout_height="200dp"
  33.             android:layout_marginTop="50dp"
  34.             android:paddingTop="20dp"
  35.             android:scaleType="centerCrop" />
  37.         <TextView
  38.             android:id="@+id/textView"
  39.             android:layout_width="wrap_content"
  40.             android:layout_height="wrap_content"
  41.             android:layout_below="@+id/imageView"
  42.             android:layout_margin="10dp"
  43.             android:textSize="16sp" />
  45.         <CheckBox
  46.             android:id="@+id/passc"
  47.             android:layout_width="wrap_content"
  48.             android:layout_height="wrap_content"
  49.             android:layout_below="@id/textView"
  50.             android:text="通过" />
  52.         <CheckBox
  53.             android:id="@+id/failc"
  54.             android:layout_width="wrap_content"
  55.             android:layout_height="wrap_content"
  56.             android:layout_below="@id/textView"
  57.             android:layout_toRightOf="@+id/passc"
  58.             android:text="失败" />
  60.     </RelativeLayout>
  62. </androidx.constraintlayout.widget.ConstraintLayout>

然后从 RecyclerAdapter.class 控制复选框的行为。

英文:

Change the code of your student_item.xml to this :

  1. &lt;?xml version=&quot;1.0&quot; encoding=&quot;utf-8&quot;?&gt;
  2. &lt;androidx.constraintlayout.widget.ConstraintLayout xmlns:android=&quot;http://schemas.android.com/apk/res/android&quot;
  3.     xmlns:app=&quot;http://schemas.android.com/apk/res-auto&quot;
  4.     xmlns:tools=&quot;http://schemas.android.com/tools&quot;
  5.     android:layout_width=&quot;match_parent&quot;
  6.     android:layout_height=&quot;wrap_content&quot;&gt;
  9.     &lt;androidx.cardview.widget.CardView
  10.         android:layout_width=&quot;match_parent&quot;
  11.         android:layout_height=&quot;wrap_content&quot;
  12.         android:layout_marginTop=&quot;50dp&quot;
  13.         android:foreground=&quot;?android:attr/selectableItemBackground&quot;
  14.         app:cardElevation=&quot;2dp&quot;
  15.         app:layout_constraintEnd_toEndOf=&quot;parent&quot;
  16.         app:layout_constraintStart_toStartOf=&quot;parent&quot;
  17.         app:layout_constraintTop_toTopOf=&quot;parent&quot;&gt;
  19.     &lt;/androidx.cardview.widget.CardView&gt;
  21.     &lt;RelativeLayout
  22.         android:id=&quot;@+id/relativeLayout2&quot;
  23.         android:layout_width=&quot;match_parent&quot;
  24.         android:layout_height=&quot;match_parent&quot;
  25.         android:padding=&quot;5dp&quot;
  27.         tools:layout_editor_absoluteX=&quot;0dp&quot;
  28.         tools:layout_editor_absoluteY=&quot;52dp&quot;&gt;
  30.         &lt;ImageView
  31.             android:id=&quot;@+id/imageView&quot;
  32.             android:layout_width=&quot;match_parent&quot;
  33.             android:layout_height=&quot;200dp&quot;
  34.             android:layout_marginTop=&quot;50dp&quot;
  35.             android:paddingTop=&quot;20dp&quot;
  36.             android:scaleType=&quot;centerCrop&quot; /&gt;
  38.         &lt;TextView
  39.             android:id=&quot;@+id/textView&quot;
  40.             android:layout_width=&quot;wrap_content&quot;
  41.             android:layout_height=&quot;wrap_content&quot;
  42.             android:layout_below=&quot;@+id/imageView&quot;
  43.             android:layout_margin=&quot;10dp&quot;
  44.             android:textSize=&quot;16sp&quot; /&gt;
  46.         &lt;CheckBox
  47.             android:id=&quot;@+id/passc&quot;
  48.             android:layout_width=&quot;wrap_content&quot;
  49.             android:layout_height=&quot;wrap_content&quot;
  50.             android:layout_below=&quot;@id/textView&quot;
  51.             android:text=&quot;pass&quot; /&gt;
  53.         &lt;CheckBox
  54.             android:id=&quot;@+id/failc&quot;
  55.             android:layout_width=&quot;wrap_content&quot;
  56.             android:layout_height=&quot;wrap_content&quot;
  57.             android:layout_below=&quot;@id/textView&quot;
  58.             android:layout_toRightOf=&quot;@+id/passc&quot;
  59.             android:text=&quot;fail&quot; /&gt;
  61.     &lt;/RelativeLayout&gt;
  63. &lt;/androidx.constraintlayout.widget.ConstraintLayout&gt;

and control the behaviour of the checkboxes from RecyclerAdapter.class

答案4

得分: 1

步骤1：在一个XML文件中添加RecyclerView。

步骤2：在另一个XML文件中，将必须放在RecyclerView内部的元素添加进去（在此处添加所需的按钮）。

步骤3：将这两个XML文件链接起来。

这样，每次动态插入后，都会添加一个按钮。

希望您能找到解决方案。

英文:

Step 1: Add the recyclerview in one xml file.

Step 2: The elements that must be inside a reecyclerview in another xml file (Here add a button that you need).

Step 3: Link these two xml files.

Thus after each insertion dynamically a button will be added.

Hope you will find the solution.

huangapple
  • 本文由 发表于 2020年7月27日 03:55:44
  • 转载请务必保留本文链接：https://java.coder-hub.com/63105037.html
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