java - 动态打印数组列表值

Question

我正在开发一个应用程序，它接受用户的输入并将其存储在数组列表中以进行统计分析。我想在另一个 Activity 中以表格形式输出这些项目和值。

我可以通过 Intent 将值传递给下一个 Activity ，但不知道如何以表格形式动态添加 View 并显示数组列表的内容。

这是添加项目的代码:

public void addItem(View view) {
        TextView itemTextView = findViewById(R.id.item_text);
        TextView quantityTextView = findViewById(R.id.quantity_text);
        TextView ratingTextView = findViewById(R.id.watt_rating_text);
        TextView hoursTextView = findViewById(R.id.hour_text);
        TextView powerFactorTextView = findViewById(R.id.power_factor_text);

        String itemValue = itemTextView.getText().toString();
        String quantityValue = quantityTextView.getText().toString();
        String ratingValue = ratingTextView.getText().toString();
        String hoursValue = hoursTextView.getText().toString();
        String powerFactorValue = powerFactorTextView.getText().toString();

        if (itemValue.isEmpty() || quantityValue.isEmpty() || ratingValue.isEmpty() || hoursValue.isEmpty() || powerFactorValue.isEmpty()){
            Toast.makeText(this, "You must input all fields", Toast.LENGTH_LONG).show();
        }
        else {
            mSolarCalc.addItem(itemValue);
            mSolarCalc.addQuantity(Integer.parseInt(quantityValue));
            mSolarCalc.addRating(Double.parseDouble(ratingValue));
            mSolarCalc.addHours(Double.parseDouble(hoursValue));
            mSolarCalc.addPowerFactor(Double.parseDouble(powerFactorValue));

            TextView itemUpdate = findViewById(R.id.item_update);
            String itemUpdateString = itemUpdate.getText().toString();
            int itemUpdateInt = Integer.parseInt(itemUpdateString);
            mItemUpdatedInt = ++itemUpdateInt;
            itemUpdate.setText(Integer.toString(mItemUpdatedInt));


            itemTextView.setText("");
            quantityTextView.setText("");
            ratingTextView.setText("");
            hoursTextView.setText("");
            powerFactorTextView.setText("");
        }
    }

这是将数据传递到另一个 Activity 的代码:

public void calculate(View view) {
       if (mSolarCalc.getItem().size() == 0){
           Toast.makeText(this, "You must add at least one item", Toast.LENGTH_LONG).show();
       }
       else {
           mSolarCalc.calculateApparentPower();
           mSolarCalc.calculatePower();
           mSolarCalc.calculateEnergy();

           double totalPower = 0;
           double totalEnergy = 0;
           for (int count = 0; count < mSolarCalc.getItem().size(); count++){
               totalPower = totalPower + mSolarCalc.getPower().get(count);
               totalEnergy = totalEnergy + mSolarCalc.getEnergy().get(count);
           }
           Intent intent = new Intent(this, SummaryActivity.class);
           intent.putExtra(SummaryActivity.POWER_RESULT, totalPower);
           intent.putExtra(SummaryActivity.ENERGY_RESULT, totalEnergy);
           intent.putExtra(SummaryActivity.ITEM_LIST, (Serializable) mSolarCalc.getItem());
           intent.putExtra(SummaryActivity.QUANTITY_LIST, (Serializable) mSolarCalc.getQuantity());
           intent.putExtra(SummaryActivity.WATTAGE_LIST, (Serializable) mSolarCalc.getRatingWattage());
           intent.addFlags(Intent.FLAG_ACTIVITY_NO_ANIMATION);
           startActivity(intent);
       }
    }

如何以表格形式显示商品、数量和瓦数？它们被声明为:

private List<String> mItem = new ArrayList<>();
private List<Integer> mQuantity = new ArrayList<>();
private List<Double> mRatingWattage = new ArrayList<>();

Answer 1

这里我发布了一个示例答案。

假设我通过 Intent 将 ArrayList 传递给另一个 Activity 并以表格形式显示它们。要求:

1 RecyclerView 和

2 RecyclerView Adapter 设置数据。

动态表 Activity

import java.util.ArrayList;

public class DynamicTableActivity extends AppCompatActivity {

    @Override
    public void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_dynamic_table);
        ArrayList<UserInput> userInputs = getIntent().getParcelableArrayListExtra("userInputs");

        Log.i(DynamicTableActivity.class.getSimpleName(),userInputs.toString());

        RecyclerView dynamicTable = findViewById(R.id.dynamic_table_view);

        dynamicTable.setLayoutManager(new LinearLayoutManager(this));
        dynamicTable.setAdapter(new MyTableAdapter(userInputs));
    }
}

我的表适配器

public class MyTableAdapter extends RecyclerView.Adapter<MyTableAdapter.MyViewHolder> {

    ArrayList<UserInput> userInputs;
    MyTableAdapter(ArrayList<UserInput> userInputs){
        this.userInputs = userInputs;
    }
    @NonNull
    @Override
    public MyViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {

        View itemViews = LayoutInflater.from(parent.getContext()).inflate(R.layout.table_item_view,parent,false);
        return new MyViewHolder(itemViews);
    }

    @Override
    public void onBindViewHolder(@NonNull MyViewHolder myViewHolder, int position) {


        myViewHolder.cell1.setText(userInputs.get(position).getName());
        myViewHolder.cell2.setText(""+userInputs.get(position).getRoll_no());

    }

    @Override
    public int getItemCount() {
        Log.i(MyTableAdapter.class.getSimpleName(),"Size:"+userInputs.size());
        return userInputs.size();
    }

    static class MyViewHolder extends RecyclerView.ViewHolder{

        TextView cell1,cell2;
        public MyViewHolder(@NonNull View itemView) {
            super(itemView);
            cell1 = itemView.findViewById(R.id.cell1);
            cell2 = itemView.findViewById(R.id.cell2);

        }
    }

}

activity_dynamic_table.xml

<android.support.v7.widget.RecyclerView 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"
    tools:context=".DynamicTableActivity"
    android:id="@+id/dynamic_table_view"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

希望有帮助。快乐编码。如果有帮助请投票。

完整代码是here谢谢。