如何获取动态添加EditText的资源数值并求和，生成双切片饼图？

1. 修正SecondActivity的视图绑定错误 #

你在addView方法里把动态添加的EditText错误绑定成了TextView，这会导致无法获取输入值，先修正这个问题：

private void addView(){
    View newResource = getLayoutInflater().inflate(R.layout.row_add_data, null, false);
    ImageView imageClose = (ImageView)newResource.findViewById(R.id.Remove);
    // 修正：将TextView改为EditText
    EditText RN = (EditText) newResource.findViewById(R.id.RName);
    EditText RA = (EditText) newResource.findViewById(R.id.RAmount);
    AppCompatSpinner COP = (AppCompatSpinner) newResource.findViewById(R.id.ColourOP);

    ArrayAdapter arrayAdapter = new ArrayAdapter(this, android.R.layout.simple_spinner_item, ColourList);
    COP.setAdapter(arrayAdapter);

    imageClose.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            removeView(newResource);
        }
    });

    linearLayout.addView(newResource);
}

2. 在ThirdActivity中计算资源总和 #

拿到传递过来的resultList后，遍历计算所有资源数量的总和：

public class ThirdActivity extends AppCompatActivity {
    RecyclerView recycle_results;
    ArrayList<Results> resultList = new ArrayList<>();
    PieChart pieChart; // 后续饼图用

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.thirdactivity);

        recycle_results = findViewById(R.id.res_results);
        pieChart = findViewById(R.id.pie_chart);

        LinearLayoutManager linearLayoutManager = new LinearLayoutManager(this, RecyclerView.VERTICAL, false);
        recycle_results.setLayoutManager(linearLayoutManager);

        resultList = (ArrayList<Results>) getIntent().getExtras().getSerializable("list");

        // 计算所有资源数量总和
        int totalAmount = 0;
        for(Results res : resultList) {
            totalAmount += res.getResAmount();
        }

        // 传入总和到适配器，用于显示占比
        recycle_results.setAdapter(new ResultsAdapter(resultList, totalAmount));

        // 初始化饼图
        setupPieChart(totalAmount);
    }
}

3. 修改ResultsAdapter显示占比 #

更新适配器，接收总和参数并计算每个资源的占比：

public class ResultsAdapter extends RecyclerView.Adapter<ResultsAdapter.ResultsView> {

    ArrayList<Results> resultList = new ArrayList<>();
    int totalAmount;

    // 构造方法新增总和参数
    public ResultsAdapter(ArrayList<Results> resultList, int totalAmount) {
        this.resultList = resultList;
        this.totalAmount = totalAmount;
    }

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

    @Override
    public void onBindViewHolder(@NonNull ResultsView holder, int position) {
        Results results = resultList.get(position);
        holder.resourceName.setText(results.getResName());
        holder.resourceAmount.setText(String.valueOf(results.getResAmount()));
        
        // 计算并显示占比
        float percentage = totalAmount == 0 ? 0 : (results.getResAmount() * 100f) / totalAmount;
        holder.resourceTotal.setText(String.format("占比: %.1f%%", percentage));
    }

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

    public class ResultsView extends RecyclerView.ViewHolder{
        TextView resourceName, resourceAmount, resourceTotal;
        public ResultsView(@NonNull View itemView) {
            super(itemView);
            resourceName = (TextView) itemView.findViewById(R.id.resNa);
            resourceAmount = (TextView) itemView.findViewById(R.id.resAm);
            resourceTotal = (TextView) itemView.findViewById(R.id.resTot);
        }
    }
}

4. 集成饼图展示（使用MPAndroidChart） #

4.1 添加依赖 #

在Module级别的build.gradle中添加饼图库依赖：

dependencies {
    implementation 'com.github.PhilJay:MPAndroidChart:v3.1.0'
}

4.2 修改thirdactivity.xml布局 #

添加饼图控件到布局顶部：

<?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=".ThirdActivity">

    <LinearLayout
        android:id="@+id/layoutThird"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:orientation="vertical"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">

        <com.github.mikephil.charting.charts.PieChart
            android:id="@+id/pie_chart"
            android:layout_width="match_parent"
            android:layout_height="250dp"
            android:layout_margin="10dp"/>

        <androidx.recyclerview.widget.RecyclerView
            android:id="@+id/res_results"
            android:layout_width="match_parent"
            android:layout_height="match_parent"></androidx.recyclerview.widget.RecyclerView>

    </LinearLayout>
</androidx.constraintlayout.widget.ConstraintLayout>

4.3 配置饼图逻辑 #

在ThirdActivity中添加饼图初始化方法：

import com.github.mikephil.charting.components.Description;
import com.github.mikephil.charting.data.PieData;
import com.github.mikephil.charting.data.PieDataSet;
import com.github.mikephil.charting.data.PieEntry;
import com.github.mikephil.charting.utils.ColorTemplate;
import android.graphics.Color;

// ... 其他导入

private void setupPieChart(int totalAmount) {
    ArrayList<PieEntry> entries = new ArrayList<>();
    for(Results res : resultList) {
        // 计算每个资源的占比
        float percentage = totalAmount == 0 ? 0 : (res.getResAmount() * 100f) / totalAmount;
        entries.add(new PieEntry(percentage, res.getResName()));
    }

    // 配置数据集
    PieDataSet dataSet = new PieDataSet(entries, "资源分布");
    dataSet.setColors(ColorTemplate.MATERIAL_COLORS);
    dataSet.setValueTextSize(12f);
    dataSet.setValueTextColor(Color.BLACK);

    // 绑定数据到饼图
    PieData data = new PieData(dataSet);
    pieChart.setData(data);

    // 设置图表描述
    Description description = new Description();
    description.setText("资源占比饼图");
    pieChart.setDescription(description);
    
    // 刷新图表
    pieChart.invalidate();
}

5. 验证功能 #

现在运行程序：

1. 在SecondActivity动态添加资源，输入名称和数量，选择颜色
2. 点击提交，ThirdActivity会显示资源列表（带占比）和对应的饼图
3. 总和计算和饼图展示功能正常

内容的提问来源于stack exchange，提问作者FPStruck