動態打印 arraylist 值

Question

請我正在開發一個應用程序，該應用程序從用戶那里獲取輸入並將它們存儲在數組列表中以進行統計分析。 我想將 output 這些項目和值以表格形式放在另一個活動上。

我可以通過意圖將值傳遞給下一個活動，但不知道如何以表格形式動態添加視圖並顯示數組列表的內容。

這是添加項目的代碼：

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("");
        }
    }

這是將數據傳遞給另一個活動的代碼：

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);
       }
    }

如何以表格形式顯示項目、數量和瓦數？ 它們被聲明為：

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

Answer 1

在這里，我發布了一個示例答案。

假設我通過意圖將 ArrayList 傳遞給另一個 Activity 並以表格形式顯示它們。 要求：

1 RecyclerView 和

2 RecyclerView Adapter 設置數據。

動態表活動

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));
    }
}

我的表適配器

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" />

希望能幫助到你。 快樂編碼。 如果有幫助，請投票。

完整代碼在這里謝謝。