Question

我有一个对象数组。在我的listview中，我只传递这些对象的名称，但当有人点击其中任何一个时，我想要一个新窗口弹出并查看我的项目中的额外信息。我能以某种方式这样做吗？

这就是我的列表活动的样子：

public class ListItemsActivity extends ListActivity {
    String[] mTestArray;
    ListView listView;
    private static final String TAG = "ListActivity";

    @Override
    public void onCreate(Bundle savedInstanceState) {
        Log.d(TAG, "Trying to create the list activitye");
        super.onCreate(savedInstanceState);
        ArrayAdapter<String> adapter;

        mTestArray = getResources().getStringArray(R.array.sections);
        ArrayList<Sweet> sweets = getSweets(mTestArray);
        ArrayList<String> result = getSweetsNames(mTestArray);
        Log.d(TAG, mTestArray.toString());

        adapter = new ArrayAdapter<String>(
                this,
                R.layout.activity_list_items,
                result;
        setListAdapter(adapter);
    }

    public void onListItemClick(ListView parent, View v, int position, long id) {
        parent.setItemChecked(position, parent.isItemChecked(position));

        Toast.makeText(this, "You have selected " + mTestArray[position],
                Toast.LENGTH_SHORT).show();
    }

所以这没关系，它给我看了一些名字。当我点击它们时，它会告诉我一个小弹出的东西，我选择了它。我想要的实际上是打开一个新窗口并显示我的项目中的所有信息。那可能吗？我该如何去做呢？

我发现的唯一方法是做这样的事情：

public void onItemClick(AdapterView<?> parent, View view,
  int position, long id) {
   switch( position ) {
     case 0:  Intent newActivity = new Intent(this, i1.class);     
              startActivity(newActivity);
              break;
     case 1:  Intent newActivity = new Intent(this, i2.class);     
              startActivity(newActivity);
              break;
     case 2:  Intent newActivity = new Intent(this, i3.class);     
              startActivity(newActivity);
              break;
     case 3:  Intent newActivity = new Intent(this, i4.class);     
              startActivity(newActivity);
              break;
     case 4:  Intent newActivity = new Intent(this, i5.class);     
              startActivity(newActivity);
              break;
    }
}

但出于以下原因，这是一个糟糕的方法： 1）我有不明数量的元素 2）我没有为每个项目有1000个活动，我想要1个通用窗口，它取决于某个整数位置。

我可以这样做吗？

Answer 1

如果您从listView获取该项目的位置，那么我认为您可以通过使用适配器获取有关该项目的信息。

您可以尝试的代码：

制作列表视图项目的xml：

这可以包括任何类型的项目，并且可以在列表视图中看到您想要显示的项目。我正在创建一个名为 list_items_view.xml 的xml，并在listview中只包含一个文本视图。

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <TextView
        android:id="@+id/nameInList"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="26dp"
        android:padding="7dp"/>

</RelativeLayout>

创建一个包含要与每个列表项绑定的项目的类：

这里我将每个列表项与它的描述，价格和卡路里绑定（你可以根据需要改变它），并为每一个创建构造函数和getter-setter方法。类的名称是的 ListDetailsClass ：

public class ListDetailsClass { String price,name, description,calories; public String getPrice() { return price; } public void setPrice(String price) { this.price = price; } public ListDetailsClass(String price, String name, String description, String calories) { this.price = price; this.name = name; this.description = description; this.calories = calories; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getDescription() { return description; } public void setDescription(String description) { this.description = description; } public String getCalories() { return calories; } public void setCalories(String calories) { this.calories = calories; } }

制作一个可以在一个项目中调整xml和类的属性的适配器：

这里我创建了一个扩展 BaseAdapter 的适配器类，并根据我的用途实现了它的方法。类的名称是 adapterForLV ：< / p>
public class adapterForLV extends BaseAdapter { ArrayList<ListDetailsClass> itemsInList; Context mContext; LayoutInflater inflater; public Context getmContext() { return mContext; } public void setmContext(Context mContext) { this.mContext = mContext; } public ArrayList<ListDetailsClass> getItemsInList() { return itemsInList; } public void setItemsInList(ArrayList<ListDetailsClass> itemsInList) { this.itemsInList = itemsInList; } public adapterForLV(ArrayList<ListDetailsClass> itemsInList, Context mContext) { this.itemsInList = itemsInList; this.mContext = mContext; } @Override public int getCount() { return itemsInList.size(); } @Override public Object getItem(int position) { return itemsInList.get(position); } @Override public long getItemId(int position) { return position; } @Override public View getView(int position, View convertView, ViewGroup parent) { if(inflater == null){ inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE); } if(convertView == null){ convertView = inflater.inflate(R.layout.list_items_view,null); } TextView nameOfItem = (TextView) convertView.findViewById(R.id.nameInList); ListDetailsClass items = itemsInList.get(position); String name = items.getName(); nameOfItem.setText(items.getName()); return convertView; } }

最后在主要活动中实施适配器，以便包含带有绑定数据的列表项：（活动名称为 MainActivity ）

ListView listView; ArrayList<ListDetailsClass> list = new ArrayList<>(); adapterForLV customAdapter; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); listView = (ListView) findViewById(R.id.lv) ; //Adapted the list form with customAdapter customAdapter = new adapterForLV(list,this); //Set the listview to the customAdapter listView.setAdapter(customAdapter); //Made two new objects of the ListDetaisClass to add data in the listview ListDetailsClass newData = new ListDetailsClass("3$","abc","description","543 cal"); ListDetailsClass newData2 = new ListDetailsClass("35.3$","item name","description about item","callories about it"); //Added data to the list list.add(newData); list.add(newData2); //Listview item click listener implementation listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { String name = customAdapter.getItemsInList().get(position).getName(); String description = customAdapter.getItemsInList().get(position).getDescription(); String price = customAdapter.getItemsInList().get(position).getPrice(); String calories = customAdapter.getItemsInList().get(position).getCalories(); //Intent to pass the data of the list item to next activity Intent i = new Intent(getApplicationContext(),Main2Activity.class); i.putExtra("Item_Name",name); i.putExtra("Item_Desc",description); i.putExtra("Item_Price",price); i.putExtra("Item_cal",calories); startActivity(i); } }); }

根据我们在新活动中的用途获取表单中显示的数据：

在这里，你必须为新活动定义一个新的xml，以便数据可以以我们想要的形式显示。

<强> Main2Activity ：

//defined textViews to show my data TextView itemName,itemDescription,itemPrice,itemCal; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main2); Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar); setSupportActionBar(toolbar); itemName = (TextView) findViewById(R.id.ItemName); itemDescription = (TextView) findViewById(R.id.ItemDescr); itemCal = (TextView) findViewById(R.id.ItemCal); itemPrice = (TextView) findViewById(R.id.ItemPrice); //Getting data from oldActivity i.e. MainActivity Intent i = getIntent(); //Setting data to textViews itemName.setText("Name: "+i.getStringExtra("Item_Name")); itemDescription.setText("Description: "+i.getStringExtra("Item_Desc")); itemPrice.setText("Price: "+i.getStringExtra("Item_Price")); itemCal.setText("Calories: "+i.getStringExtra("Item_cal")); }

实施后的屏幕截图：

的列表视图

新活动中的商品详情

希望这对你有帮助！

Answer 2

我不太了解但您可以将Intent用于新窗口例如：

public void onListItemClick(ListView parent, View v, int position, long id) {
    parent.setItemChecked(position, parent.isItemChecked(position));

   Intent intent=new Intent(ListItemActivity.this, newDetailActivity.class);  //newDetailActivity is a Activity you need to create or can say redirect window
 startActivity(intent);  // This opens a window
}

此处的官方文档了解更多信息Component-Relative Paths in Angular 2

Answer 3

您可以开始一项公共活动，并将所选项目与意图一起传递：

public void onListItemClick(ListView parent, View v, int position, long id) {
    parent.setItemChecked(position, parent.isItemChecked(position));

    //DetailsActivity is the activity which shows the extra details
    Intent intent=new Intent(ListItemActivity.this, DetailsActivity.class);  

    //Add the item that the user clicked on, the class has to implement Parcelable or Serializable
    intent.putExtra("data", sweets.getItem(position));
    startActivity(intent);  // This opens a window
}

在已打开的活动中，您可以从意图中获取该项目并显示其内容：

//in newDetailActivity :
Sweet s = getIntent().getExtras.getParcelable("data");

Answer 4

在活动之间传递数据的最简单方法是使用意图。

public void onItemClick(AdapterView<?> parent, View view,
          int position, long id) {

     Intent newActivity = new Intent(this, i1.class);
     newActivity.putExtra("id", postion);
     newActivity.putExtra("key", value);        
     startActivity(newActivity);

    }

简而言之，putExtra方法需要一个键和值可在目的地活动中检索。

Bundle extras = getIntent().getExtras();
String id,key;
    if(extras == null) {
        id = null;
        key = null; 
    } else {
        id= extras.getString("id");
        key= extras.getString("key");
    }

OnClickItem，Android项目数量未知

4 个答案: