Question

我正在创建一个购物车应用程序，我正在尝试填充一个名为items的String []产品。每个项目都有一个ID，一个名称和一个价格。我遇到的问题是我正在尝试制作一个自定义ListView但我无法让它在我的Android设备上运行。每次我使用客户ListView时它都会崩溃。也许我做得不对，或者我也需要创建一个客户适配器？我尝试过这些方法，但都没有成功。这就是我所拥有的，我目前正在使用simple_list_item_check布局，但我只是实现了它以查看它是否可行，其中就是这样。 Android简单的布局，但我的自定义不会。任何人都可以带领我朝着正确的方向前进吗？

CustomerView.activity

    import android.support.v7.app.ActionBarActivity;
    import android.os.Bundle;
    import android.view.Menu;
    import android.view.MenuItem;
    import android.view.View;
    import android.widget.AdapterView;
    import android.widget.ArrayAdapter;
    import android.widget.ListAdapter;
    import android.widget.ListView;
    import android.widget.Toast;
    import android.widget.CheckedTextView;


    public class CustomerView extends ActionBarActivity {

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

    Product[] items = {
            new Product(1, "Milk", 21.50),
            new Product(2, "Butter", 15.99),
            new Product(3, "Yogurt", 14.90),
            new Product(4, "Toothpaste", 7.99),
            new Product(5, "Ice Cream", 10.00),

    };

    final ListAdapter theAdapter = new ArrayAdapter<>(this,
            android.R.layout.simple_list_item_checked, items);

    ListView customerlist = (ListView) findViewById(R.id.customerList);
    customerlist.setTextFilterEnabled(true);
    customerlist.setAdapter(theAdapter);
    customerlist.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            CheckedTextView check = (CheckedTextView)view;
            check.setChecked(!check.isChecked());
            String itemselected = "You Touched " +
                  String.valueOf(theAdapter.getItem(position));

            Toast.makeText(CustomerView.this, itemselected, Toast.LENGTH_SHORT).show();

        }
    });

}





@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_customer_view, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}
}

Product.java

    public class Product {

private int id;
private String name;
private double price;
private boolean selected;


public Product(int id, String name, double price) {
    this.id = id;
    this.name = name;
    this.price = price;

}

@Override
public String toString() {
    return this.id + " " + this.name + " [$" + this.price + "]";
}
}

row_layout.xml

    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
tools:context="shoppingcart.cop4331.com.shoppingcart.CustomerView">


<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Add to Cart"
    android:gravity="right"
    />


<TextView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/textview1"
    android:textSize="20sp"/>



    </LinearLayout>

Answer 1

更改行：

final ListAdapter theAdapter = new ArrayAdapter<>(this,
        android.R.layout.simple_list_item_checked, items);

为：

final ListAdapter theAdapter = new ArrayAdapter<>(this,
           R.layout.row_layout , R.id.textview1, items);

你使用错误的ArrayAdapter构造函数:) 如果根视图不是TextView（在您的情况下根视图是LinearLayout），则必须传递TextView id

Answer 2

您需要实现ProductsAdapter。您正在使用的ArrayAdapter构造函数正在尝试设置仅检查项目布局的列表，这些布局在给定产品的情况下无效。您必须创建一个简单的适配器，它将Product对象中的每个变量映射到row_layout.xml。

您可以在此之后为适配器建模 - https://github.com/ucsunil/receipts/blob/master/app/src/main/java/com/amex/receipts/adapters/ItemsAdapter.java。这是我在某个时候做过的练习项目，它是将项目添加到购物车中。你基本上会覆盖getView（）方法来绑定你的视图。

Answer 3

我会创建一个自定义适配器类，并在该适配器类中有一个回调。您可以修改此代码以获取String []或ArrayList，并使用XML布局。

这个示例代码有点矫枉过正，但这是我现在提供示例所能做的最好的。

public class WorkoutCardsAdapter extends ArrayAdapter<WorkoutView> {

private LayoutInflater mInflater;
String TAG = WorkoutCardsAdapter.class.getCanonicalName();
Callback mCallback;
List<WorkoutView> mViews;

public WorkoutCardsAdapter(Context context, List<WorkoutView> views, Callback callback) {
    super(context, 0, views);
    mInflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    mCallback = callback;
    this.mViews = views;
}

@Override
public View getView(final int position, View convertView, ViewGroup parent) {
    final ViewHolder holder;
    WorkoutView workoutView = getItem(position);
    convertView = null;


    if (convertView == null) {
        holder = new ViewHolder();
        if (workoutView.getWorkoutMainCategory().equals("Traditional")) {
            if (workoutView.getWorkoutType().equals("Strength")) {
                if (workoutView.getWorkoutCategory().equals("Weightlifting")) {
                    convertView = mInflater.inflate(R.layout.single_workout_layout_traditional_weights, parent, false);
                    holder.tvWorkoutType = (TextView) convertView.findViewById(R.id.textViewWorkoutTypeItem);
                    holder.tvWorkoutCategory = (TextView) convertView.findViewById(R.id.textViewWorkoutCategoryItem);
                    holder.tvSetsItem = (TextView) convertView.findViewById(R.id.textViewSetsItem);
                    holder.tvRepsItem = (TextView) convertView.findViewById(R.id.textViewRepsItem);
                    holder.tvWorkoutName = (TextView) convertView.findViewById(R.id.textViewWorkoutName);
                    holder.tvWorkoutWeight = (TextView) convertView.findViewById(R.id.textViewWorkoutWeightItem);
                    holder.btnRemoveWorkout = (Button) convertView.findViewById(R.id.btnRemoveWorkout);
                    convertView.setTag(holder);
                } else if (workoutView.getWorkoutCategory().equals("Isometric") || workoutView.getWorkoutCategory().equals("Circuit") ||
                        workoutView.getWorkoutCategory().equals("Other")) {
                    convertView = mInflater.inflate(R.layout.single_workout_layout_traditional_strength, parent, false);
                    holder.tvWorkoutType = (TextView) convertView.findViewById(R.id.textViewWorkoutTypeItem);
                    holder.tvWorkoutCategory = (TextView) convertView.findViewById(R.id.textViewWorkoutCategoryItem);
                    holder.tvWorkoutName = (TextView) convertView.findViewById(R.id.textViewWorkoutName);
                    holder.tvDescription = (TextView) convertView.findViewById(R.id.textViewWorkoutDescriptionItem);
                    holder.btnRemoveWorkout = (Button) convertView.findViewById(R.id.btnRemoveWorkout);
                    convertView.setTag(holder);
                }
            } else if (workoutView.getWorkoutType().equals("Endurance")){
                if(workoutView.getWorkoutCategory().equals("Running")){
                    convertView = mInflater.inflate(R.layout.single_workout_layout_traditional_endurance, parent, false);
                    holder.tvWorkoutType = (TextView) convertView.findViewById(R.id.textViewWorkoutTypeItem);
                    holder.tvWorkoutCategory = (TextView) convertView.findViewById(R.id.textViewWorkoutCategoryItem);
                    holder.tvWorkoutName = (TextView) convertView.findViewById(R.id.textViewWorkoutName);
                    holder.tvDescription = (TextView) convertView.findViewById(R.id.textViewWorkoutDescriptionItem);
                    holder.btnRemoveWorkout = (Button) convertView.findViewById(R.id.btnRemoveWorkout);

                } else if (workoutView.getWorkoutCategory().equals("Other")){
                   convertView = mInflater.inflate(R.layout.single_workout_layout_traditional_endurance, parent, false);
                    holder.tvWorkoutType = (TextView) convertView.findViewById(R.id.textViewWorkoutTypeItem);
                    holder.tvWorkoutCategory = (TextView) convertView.findViewById(R.id.textViewWorkoutCategoryItem);
                    holder.tvWorkoutName = (TextView) convertView.findViewById(R.id.textViewWorkoutName);
                    holder.tvDescription = (TextView) convertView.findViewById(R.id.textViewWorkoutDescriptionItem);
                    holder.btnRemoveWorkout = (Button) convertView.findViewById(R.id.btnRemoveWorkout);
                }
            } else if (workoutView.getWorkoutType().equals("Other")){
                convertView = mInflater.inflate(R.layout.single_workout_layout_traditional_other, parent, false);
                holder.tvWorkoutType = (TextView) convertView.findViewById(R.id.textViewWorkoutTypeItem);
                holder.tvWorkoutName = (TextView) convertView.findViewById(R.id.textViewWorkoutName);
                holder.tvDescription = (TextView) convertView.findViewById(R.id.textViewWorkoutDescriptionItem);
                holder.btnRemoveWorkout = (Button) convertView.findViewById(R.id.btnRemoveWorkout);
            }
        } else if (workoutView.getWorkoutMainCategory().equals("CrossFit")) {
            //TODO: DEFINE CROSSFIT
            if(workoutView.getWorkoutType().equals("For Reps & Time")){
                convertView = mInflater.inflate(R.layout.single_workout_layout_crossfit_repstime, parent, false);
                holder.tvWorkoutType = (TextView) convertView.findViewById(R.id.textViewWorkoutTypeItem);
                holder.tvWorkoutName = (TextView) convertView.findViewById(R.id.textViewWorkoutName);
                holder.tvDescription = (TextView) convertView.findViewById(R.id.textViewWorkoutDescriptionItem);
                holder.tvSetsItem = (TextView) convertView.findViewById(R.id.textViewSetsItem);
                holder.tvRepsItem = (TextView) convertView.findViewById(R.id.textViewRepsItem);
                holder.btnRemoveWorkout = (Button) convertView.findViewById(R.id.btnRemoveWorkout);
            } else if (workoutView.getWorkoutType().equals("For Reps")){
                convertView = mInflater.inflate(R.layout.single_workout_layout_crossfit_reps, parent, false);
                holder.tvWorkoutType = (TextView) convertView.findViewById(R.id.textViewWorkoutTypeItem);
                holder.tvWorkoutName = (TextView) convertView.findViewById(R.id.textViewWorkoutName);
                holder.tvDescription = (TextView) convertView.findViewById(R.id.textViewWorkoutDescriptionItem);
                holder.tvSetsItem = (TextView) convertView.findViewById(R.id.textViewSetsItem);
                holder.tvRepsItem = (TextView) convertView.findViewById(R.id.textViewRepsItem);
                holder.btnRemoveWorkout = (Button) convertView.findViewById(R.id.btnRemoveWorkout);

            } else if (workoutView.getWorkoutType().equals("For Time")){
                convertView = mInflater.inflate(R.layout.single_workout_layout_crossfit_time, parent, false);
                holder.tvWorkoutType = (TextView) convertView.findViewById(R.id.textViewWorkoutTypeItem);
                holder.tvWorkoutName = (TextView) convertView.findViewById(R.id.textViewWorkoutName);
                holder.tvDescription = (TextView) convertView.findViewById(R.id.textViewWorkoutDescriptionItem);
                holder.tvSetsItem = (TextView) convertView.findViewById(R.id.textViewSetsItem);
                holder.btnRemoveWorkout = (Button) convertView.findViewById(R.id.btnRemoveWorkout);
            } else if (workoutView.getWorkoutType().equals("For Weight")){
                convertView = mInflater.inflate(R.layout.single_workout_layout_crossfit_weight, parent, false);
                holder.tvWorkoutType = (TextView) convertView.findViewById(R.id.textViewWorkoutTypeItem);
                holder.tvWorkoutName = (TextView) convertView.findViewById(R.id.textViewWorkoutName);
                holder.tvDescription = (TextView) convertView.findViewById(R.id.textViewWorkoutDescriptionItem);
                holder.tvSetsItem = (TextView) convertView.findViewById(R.id.textViewSetsItem);
                holder.btnRemoveWorkout = (Button) convertView.findViewById(R.id.btnRemoveWorkout);
            } else if (workoutView.getWorkoutType().equals("Other")){
                convertView = mInflater.inflate(R.layout.single_workout_layout_traditional_other, parent, false);
                holder.tvWorkoutType = (TextView) convertView.findViewById(R.id.textViewWorkoutTypeItem);
                holder.tvWorkoutName = (TextView) convertView.findViewById(R.id.textViewWorkoutName);
                holder.tvDescription = (TextView) convertView.findViewById(R.id.textViewWorkoutDescriptionItem);
                holder.btnRemoveWorkout = (Button) convertView.findViewById(R.id.btnRemoveWorkout);
            }

        }
    } else {
        holder = (ViewHolder) convertView.getTag();
    }

    if (workoutView.getWorkoutMainCategory().equals("Traditional")) {
        if (workoutView.getWorkoutType().equals("Strength")) {
            if (workoutView.getWorkoutCategory().equals("Weightlifting")) {
                holder.tvWorkoutName.setText(workoutView.getWorkoutName());
                holder.tvWorkoutType.setText(workoutView.getWorkoutType());
                holder.tvWorkoutCategory.setText(workoutView.getWorkoutCategory());
                holder.tvWorkoutWeight.setText(workoutView.getWorkoutWeight());
                holder.tvSetsItem.setText(workoutView.getSets());
                holder.tvRepsItem.setText(workoutView.getReps());
            } else if (workoutView.getWorkoutCategory().equals("Isometric") || workoutView.getWorkoutCategory().equals("Circuit") ||
                    workoutView.getWorkoutCategory().equals("Other")) {
                holder.tvWorkoutName.setText(workoutView.getWorkoutName());
                holder.tvWorkoutType.setText(workoutView.getWorkoutType());
                holder.tvWorkoutCategory.setText(workoutView.getWorkoutCategory());
                holder.tvDescription.setText(workoutView.getWorkoutDesc());
            }
        } else if (workoutView.getWorkoutType().equals("Endurance")){
            if(workoutView.getWorkoutCategory().equals("Running")){
                holder.tvWorkoutName.setText(workoutView.getWorkoutName());
                holder.tvWorkoutType.setText(workoutView.getWorkoutType());
                holder.tvWorkoutCategory.setText(workoutView.getWorkoutCategory());
                holder.tvDescription.setText(workoutView.getWorkoutDistance());
            } else if (workoutView.getWorkoutCategory().equals("Other")){
                holder.tvWorkoutName.setText(workoutView.getWorkoutName());
                holder.tvWorkoutType.setText(workoutView.getWorkoutType());
                holder.tvWorkoutCategory.setText(workoutView.getWorkoutCategory());
                holder.tvDescription.setText(workoutView.getWorkoutDesc());
            }
        } else if (workoutView.getWorkoutType().equals("Other")){
            holder.tvWorkoutName.setText(workoutView.getWorkoutName());
            holder.tvWorkoutType.setText(workoutView.getWorkoutType());
            holder.tvDescription.setText(workoutView.getWorkoutDesc());
        }
    } else if (workoutView.getWorkoutMainCategory().equals("CrossFit")) {
        //TODO: DEFINE CROSSFIT
        if(workoutView.getWorkoutType().equals("For Reps & Time")){
            holder.tvWorkoutName.setText(workoutView.getWorkoutName());
            holder.tvWorkoutType.setText(workoutView.getWorkoutType());
            holder.tvSetsItem.setText(workoutView.getWorkoutTime());
            holder.tvRepsItem.setText(workoutView.getReps());
            holder.tvDescription.setText(workoutView.getWorkoutDesc());
        } else if (workoutView.getWorkoutType().equals("For Reps")){
            holder.tvWorkoutName.setText(workoutView.getWorkoutName());
            holder.tvWorkoutType.setText(workoutView.getWorkoutType());
            holder.tvSetsItem.setText(workoutView.getSets());
            holder.tvRepsItem.setText(workoutView.getReps());
            holder.tvDescription.setText(workoutView.getWorkoutDesc());
        } else if (workoutView.getWorkoutType().equals("For Time")){
            holder.tvWorkoutName.setText(workoutView.getWorkoutName());
            holder.tvWorkoutType.setText(workoutView.getWorkoutType());
            holder.tvSetsItem.setText(workoutView.getWorkoutTime());
            holder.tvDescription.setText(workoutView.getWorkoutDesc());
        } else if (workoutView.getWorkoutType().equals("For Weight")){
            holder.tvWorkoutName.setText(workoutView.getWorkoutName());
            holder.tvWorkoutType.setText(workoutView.getWorkoutType());
            holder.tvSetsItem.setText(workoutView.getWorkoutWeight());
            holder.tvDescription.setText(workoutView.getWorkoutDesc());
        } else if (workoutView.getWorkoutType().equals("Other")){
            holder.tvWorkoutName.setText(workoutView.getWorkoutName());
            holder.tvWorkoutType.setText(workoutView.getWorkoutType());
            holder.tvDescription.setText(workoutView.getWorkoutDesc());
        }

    }

    holder.btnRemoveWorkout = (Button) convertView.findViewById(R.id.btnRemoveWorkout);
    holder.btnRemoveWorkout.setTag(position);
    holder.btnRemoveWorkout.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            int position = (Integer) v.getTag();
            mCallback.onPressed(position);
        }
    });
    return convertView;
}

@Override
public WorkoutView getItem(final int position) {
    return mViews.get(position);
}

@Override
public int getCount() {
    return mViews.size();
}

public interface Callback {
    void onPressed(int pos);
}

private static class ViewHolder {
    public TextView tvDescription;
    public TextView tvWorkoutType;
    public TextView tvWorkoutCategory;
    public TextView tvWorkoutWeight;
    public TextView tvSetsItem;
    public TextView tvRepsItem;
    public TextView tvWorkoutName;
    public Button btnRemoveWorkout;
}
}

Answer 4

您好，请尝试删除支持库import android.support.v7.app.ActionBarActivity;

并扩展Activity而不是ActionBarActivity。我试过了，它工作正常。支持库存在一些问题。

为每个元素添加一个按钮到ListView

4 个答案: