我有一个 RecyclerView，里面只有一个 TextView。我在它外面有一个添加按钮和一个 EditText，当我按下添加按钮时，它们只接受整数并将它们添加到 RecyclerView。我的问题是如何让它计算我插入到 EditText 中的所有整数的总和。
示例:假设我在第一行的 EditText 中输入 300 将显示 300，然后如果我在 EditText 中插入 200 我想在第二行中显示 500 (300 + 200) 等等。
这是我的代码
activity_main.xml
<?xml version="1.0" encoding="utf-8"?> <LinearLayout 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="com.example.brecyclerview.MainActivity" android:orientation="vertical"> <EditText android:id="@+id/edit_ten" android:layout_width="match_parent" android:layout_height="wrap_content" android:ems="10" android:hint="Score" android:inputType="numberSigned|number" /> <LinearLayout android:orientation="horizontal" android:layout_width="match_parent" android:layout_height="wrap_content"> <Button android:id="@+id/btn_add" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_weight="1" android:onClick="btn_add" android:text="Add" tools:ignore="OnClick" /> <Button android:id="@+id/btn_undo" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_weight="1" android:onClick="btn_undo" android:text="Undo" tools:ignore="OnClick" /> <Button android:id="@+id/btn_new" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_weight="1" android:onClick="btn_new" android:text="New Game" /> </LinearLayout> <androidx.recyclerview.widget.RecyclerView android:id="@+id/recycleViewContainer" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_alignParentStart="true" android:layout_alignParentLeft="true" android:layout_alignParentTop="true" tools:itemCount="8" /> </LinearLayout>
list_item.xml
<RelativeLayout android:id="@+id/singleRow" android:layout_width="match_parent" android:layout_height="wrap_content" android:padding="8dp"> <ImageView android:id="@+id/userImg" android:src="@mipmap/ic_launcher" android:layout_width="60dp" android:layout_height="60dp" /> <TextView android:id="@+id/pNametxt" android:text="User Name" android:textSize="20sp" android:layout_marginTop="6dp" android:maxLines="1" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_alignParentTop="true" android:layout_toRightOf="@+id/userImg" android:layout_toEndOf="@+id/userImg" android:layout_marginLeft="8dp" android:layout_marginStart="8dp" /> </RelativeLayout> <View android:layout_below="@+id/singleRow" android:layout_width="match_parent" android:layout_height="1dp" android:background="#f2f2f2" />
MainActivity.java
import androidx.appcompat.app.AppCompatActivity; import androidx.recyclerview.widget.LinearLayoutManager; import androidx.recyclerview.widget.RecyclerView; import android.content.Intent; import android.os.Bundle; import android.view.View; import android.widget.Button; import android.widget.EditText; import android.widget.TextView; import android.widget.Toast; import java.util.ArrayList; import java.util.List; public class MainActivity extends AppCompatActivity { Button button; Button button1; Button button2; EditText editText; TextView personName; RecyclerView recyclerView; RecyclerView.Adapter mAdapter; RecyclerView.LayoutManager layoutManager; List<PersonUtils> personUtilsList; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); button = (Button)findViewById(R.id.btn_add); button1 = (Button)findViewById(R.id.btn_undo); button2 = (Button)findViewById(R.id.btn_new); editText = (EditText)findViewById(R.id.edit_ten); personName = (TextView)findViewById(R.id.pNametxt); recyclerView = (RecyclerView) findViewById(R.id.recycleViewContainer); recyclerView.setHasFixedSize(true); layoutManager = new LinearLayoutManager(this); recyclerView.setLayoutManager(layoutManager); personUtilsList = new ArrayList<>(); //Adding Data into ArrayList mAdapter = new CustomRecyclerAdapter(this, personUtilsList); recyclerView.setAdapter(mAdapter); button2.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { if (v == button2) { MainActivity.this.finish(); startActivity(new Intent(MainActivity.this, MainActivity.class)); }}}); button.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { int pNametxt; int total = 0; for (int i = 0; i<personUtilsList.size(); i++) { total += personUtilsList.get(i).getPersonName(); } total = Integer.parseInt(editText.getText().toString()); layoutManager = new LinearLayoutManager(getApplicationContext()); recyclerView.setLayoutManager(layoutManager); personUtilsList.add(new PersonUtils(total)); mAdapter = new CustomRecyclerAdapter(MainActivity.this, personUtilsList); recyclerView.setAdapter(mAdapter); editText.setText(""); }}); }}
CustomRecyclerAdapter.java
import android.content.Context; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.Button; import android.widget.TextView; import android.widget.Toast; import androidx.recyclerview.widget.RecyclerView; import java.util.List; public class CustomRecyclerAdapter extends RecyclerView.Adapter<CustomRecyclerAdapter.ViewHolder> { private Context context; private List<PersonUtils> personUtils; public CustomRecyclerAdapter(Context context, List personUtils) { this.context = context; this.personUtils = personUtils; } public static void remove(long i) { } @Override public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false); ViewHolder viewHolder = new ViewHolder(v); return viewHolder; } @Override public void onBindViewHolder(ViewHolder holder, int position) { holder.itemView.setTag(personUtils.get(position)); PersonUtils pu = personUtils.get(position); holder.pName.setText(String.valueOf(pu.getPersonName())); } @Override public int getItemCount() { return personUtils.size(); } public static class ViewHolder extends RecyclerView.ViewHolder{ public TextView pName; Button deleteButton; public ViewHolder(View itemView) { super(itemView); pName = (TextView) itemView.findViewById(R.id.pNametxt); deleteButton = (Button) itemView.findViewById(R.id.btn_undo); } } }
PersonUtils.java
public class PersonUtils { private Integer personName; public Integer getPersonName() { return personName; } public void setPersonName(Integer personName) { this.personName = personName; } public PersonUtils(Integer personName) { this.personName = personName; } }
提前谢谢你。
最佳答案
实际上，您是在代码中完成的，但有一个简单的错误。
按钮监听器中的 MainActivity.java
int total = 0;
for (int i = 0; i<personUtilsList.size(); i++)
{
total += personUtilsList.get(i).getPersonName();
}
total = Integer.parseInt(editText.getText().toString());
它的问题是，您已经为 total 变量设置了一个新值，但它应该是 += 而不是 = 并且您的代码将按您希望的方式运行 InChaa'Allah。
但是我对你的编码方式有一些注意事项。
首先，这些行这样写是不好的。
layoutManager = new LinearLayoutManager(getApplicationContext());
recyclerView.setLayoutManager(layoutManager);
personUtilsList.add(new PersonUtils(total));
mAdapter = new CustomRecyclerAdapter(MainActivity.this, personUtilsList);
recyclerView.setAdapter(mAdapter);
会把所有的Activity生命周期都做一遍，会造成大量的CPU浪费。
所以你这样做。
((CustomRecyclerAdapter) mAdapter).addPersonUtils(new PersonUtils(total));
mAdapter.notifyDataSetChanged();//will make the RecyclerView adapter to reload its data.
在 CustomRecyclerAdapter.java 类中，我添加了一个新方法，用于向 personUtils ArrayList 添加一个新项目。
public void addPersonUtils(PersonUtils personUtil){
personUtils.add(personUtil);
}
这样代码会更好。
关于android - 每次插入一个整数时，如何计算我在 EditText 中插入的整数的总和？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/58469584/