在recyclerview android studio中动态显示按钮

lsmd5eda  于 2022-11-25  发布在  Android
关注(0)|答案(4)|浏览(207)

我正在开发一个学生追踪器应用程序,我正在尝试显示在每个学生下创建的动态按钮。我将在下面粘贴一个我希望它看起来像什么的图像。

现在,我正在硬编码第一张图片的按钮。我从我的firbase数据库中获取学生的图片和他们的名字。现在我的问题是如何为每个学生生成复选框,并确保它像上面一样直接位于他们的图片和名字下面。
在我看来,我认为算法应该是这样的
1.循环访问学生数组列表
1.为每个学生生成复选框
1.将它们放到我的recyclerView上。
我将粘贴相关代码在下面。
daily_grading.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".DailyGrading">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recyclerView"
        android:layout_width="409dp"
        android:layout_height="729dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <CheckBox
        android:id="@+id/checkBox"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="PASS"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="@+id/recyclerView"
        app:layout_constraintHorizontal_bias="0.046"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.499" />

    <CheckBox
        android:id="@+id/checkBox2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="FAIL"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.261"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.499" />

</androidx.constraintlayout.widget.ConstraintLayout>

student_item.xml

<?xml version="1.0" encoding="utf-8"?>
    <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        xmlns:tools="http://schemas.android.com/tools"
        android:layout_width="match_parent"
        android:layout_height="wrap_content">
    
    
        <androidx.cardview.widget.CardView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginTop="50dp"
            android:foreground="?android:attr/selectableItemBackground"
            app:cardElevation="2dp"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent">
    
        </androidx.cardview.widget.CardView>
    
        <RelativeLayout
            android:id="@+id/relativeLayout2"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:padding="5dp"
    
            tools:layout_editor_absoluteX="0dp"
            tools:layout_editor_absoluteY="52dp">
    
            <ImageView
                android:id="@+id/imageView"
                android:layout_width="match_parent"
                android:layout_height="200dp"
                android:layout_marginTop="50dp"
                android:paddingTop="20dp"
                android:scaleType="centerCrop" />
    
            <TextView
                android:id="@+id/textView"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_below="@+id/imageView"
                android:layout_margin="10dp"
                android:textSize="16sp" />
    
        </RelativeLayout>
    
    </androidx.constraintlayout.widget.ConstraintLayout>

DailyGrading.class

public class DailyGrading extends AppCompatActivity{

    RecyclerView recyclerView;
    Button addStudent;

    private DatabaseReference myRef;

    public ArrayList<Students> students;
    private RecyclerAdapter recyclerAdapter;
    private Button orderStudents;

    private EditText mEditTextAge;
    private EditText mEditTextAssignment;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.daily_grading);

        recyclerView = findViewById(R.id.recyclerView);
        addStudent = findViewById(R.id.addStudentButton);
        mEditTextAge = findViewById(R.id.EditTextAge);
        mEditTextAssignment = findViewById(R.id.EditTextAssignment);

        recyclerView.setLayoutManager(new GridLayoutManager(this, 2));
        recyclerView.setHasFixedSize(true);

        myRef = FirebaseDatabase.getInstance().getReference();

        students = new ArrayList<>();

        ClearAll();

        GetDataFromFirebase();


    }
    // fetches images and name from firebase
    private void GetDataFromFirebase() {
        Query query = myRef.child("student");

        query.addValueEventListener(new ValueEventListener() {
            @Override
            public void onDataChange(@NonNull DataSnapshot dataSnapshot) {
                ClearAll();
                for(DataSnapshot snapshot: dataSnapshot.getChildren()) {
                    Students student = new Students();
                    if (snapshot.child("url").getValue() == null) {
                        student.setImageUrl(snapshot.child("imageUrl").getValue().toString());
                    }
                    else {
                        student.setImageUrl(snapshot.child("url").getValue().toString());

                    }
                    student.setName(snapshot.child("name").getValue().toString());
                    students.add(student);
                }
                recyclerAdapter = new RecyclerAdapter(getApplicationContext(), students);
                recyclerView.setAdapter(recyclerAdapter);
                recyclerAdapter.notifyDataSetChanged();
            }

            @Override
            public void onCancelled(@NonNull DatabaseError databaseError) {

            }
        });
    }
    // will clear recyclerAdapter
    private void ClearAll() {
        if (students != null) {
            students.clear();

            if(recyclerAdapter != null) {
                recyclerAdapter.notifyDataSetChanged();
            }
        }
        students = new ArrayList<>();
    }

    // method to generate checkboxes dynamically
    public void generateButtonsDynamically() {
        for(int i = 0; i < students.size(); i++){
        }
    }

RecyclerAdapter.class

package com.example.studenttracker;

import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.ImageView;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

import com.bumptech.glide.Glide;

import java.util.ArrayList;

public class RecyclerAdapter extends RecyclerView.Adapter<RecyclerAdapter.ViewHolder> {
    private OnItemClickListener mListener;
    public interface OnItemClickListener {
        void onItemClick(int position);
    }
    public void setOnItemClickListener(OnItemClickListener listener) {
        mListener = listener;
    }
    private static final String Tag = "RecyclerView";
    private Context mContext;
    private ArrayList<Students> studentsArrayList;

    public RecyclerAdapter(Context mContext, ArrayList<Students> studentsArrayList) {
        this.mContext = mContext;
        this.studentsArrayList = studentsArrayList;
    }

    @NonNull
    @Override
    public RecyclerAdapter.ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext())
                .inflate(R.layout.student_item,parent,false);
        return new ViewHolder(view);

    }

    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        //TextView
        holder.textView.setText(studentsArrayList.get(position).getName());

        Glide.with(mContext).load(studentsArrayList.get(position).getImageUrl()).into(holder.imageView);

    }

    @Override
    public int getItemCount() {
        return studentsArrayList.size();
    }

    public class ViewHolder extends RecyclerView.ViewHolder {
        ImageView imageView;
        TextView textView;

        public ViewHolder(@NonNull View itemView) {
            super(itemView);

            imageView = itemView.findViewById(R.id.imageView);
            textView = itemView.findViewById(R.id.textView);
            itemView.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    if (mListener != null) {
                        int position = getAdapterPosition();
                        
                    }
                }
            });
        }
    }
}
kgsdhlau

kgsdhlau1#

student_item.xml 的代码更改为:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="wrap_content">

    <androidx.cardview.widget.CardView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="50dp"
        android:foreground="?android:attr/selectableItemBackground"
        app:cardElevation="2dp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

    </androidx.cardview.widget.CardView>

    <RelativeLayout
        android:id="@+id/relativeLayout2"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:padding="5dp"

        tools:layout_editor_absoluteX="0dp"
        tools:layout_editor_absoluteY="52dp">

        <ImageView
            android:id="@+id/imageView"
            android:layout_width="match_parent"
            android:layout_height="200dp"
            android:layout_marginTop="50dp"
            android:paddingTop="20dp"
            android:scaleType="centerCrop" />

        <TextView
            android:id="@+id/textView"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/imageView"
            android:layout_margin="10dp"
            android:textSize="16sp" />

        <CheckBox
            android:id="@+id/passc"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@id/textView"
            android:text="pass" />

        <CheckBox
            android:id="@+id/failc"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@id/textView"
            android:layout_toRightOf="@+id/passc"
            android:text="fail" />

    </RelativeLayout>

</androidx.constraintlayout.widget.ConstraintLayout>

并控制 RecyclerAdapter.class 中复选框的行为

gc0ot86w

gc0ot86w2#

试试看:

<CheckBox
        android:id="@+id/checkBox"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="PASS"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="@+id/recyclerView"
        app:layout_constraintHorizontal_bias="0.046"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.499"
        android:visibility="gone" />

    <CheckBox
        android:id="@+id/checkBox2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="FAIL"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.261"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.499"
        android:visibility="gone" />

@Override
public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
    //TextView
    holder.textView.setText(studentsArrayList.get(position).getName());

    Glide.with(mContext).load(studentsArrayList.get(position).getImageUrl()).into(holder.imageView);

    if (studentsArrayList.get(position).displayButtons()) { //check if you need the buttons or not
        holder.checkBox.setVisibility(View.VISIBLE);
        holder.checkBox2.setVisibility(View.VISIBLE);
    } else {
        holder.checkBox.setVisibility(View.GONE);
        holder.checkBox2.setVisibility(View.GONE);
    }
}
jq6vz3qz

jq6vz3qz3#

步骤1:在一个xml文件中添加recyclerview。
步骤2:必须在另一个xml文件中的reecyclerview内的元素(在这里添加您需要的按钮)。
步骤3:链接这两个xml文件。

因此,每次插入后都会动态添加一个按钮。
希望你能找到解决办法。

6ioyuze2

6ioyuze24#

在student_item. xml而不是daily_grading. xml中添加复选框

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