Question

我在transporter.sendMail({ from: 'bot@myaddress.be', to: 'info@myaddress.be', subject: data.contactEmail, text: MAILBODY });中显示getWindow().setBackgroundDrawable(new ColorDrawable(android.graphics.Color.TRANSPARENT));个对象MyBears，我想配置ArrayAdapter中我的GridView对象的排序顺序。ArrayAdapter。我想订购熊，例如GridView基于最后一个参数（在本例中为48 - 方法为new myBear(27, "Hi", 48)）。我该怎么做，我需要把这段代码放在哪里。我试图实现我在其他帖子中看到的内容，但没有一个起作用。

这是我的xml网格出现位置：

myBear.getSize()

这是我将数组适配器与网格连接的地方。

<LinearLayout 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_height="match_parent"
    android:layout_width="match_parent"
    android:background="@drawable/background_Bears"
    android:orientation="vertical”>
    <GridView
        android:id="@+id/my_Bears_in_my_collection_grid_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:divider="@android:color/transparent"
        android:gravity="center"
        android:numColumns="4"
        android:visibility="visible"
        tools:griditem="@layout/one_my_Bear_in_my_collection_display" />
</LinearLayout>

这是我的public class MyCollectionFragment extends Fragment { private GridView mMyBearGridView; @Override public View onCreateView (LayoutInflater inflater, @Nullable final ViewGroup container, @Nullable Bundle savedInstanceState){ View v = inflater.inflate(R.layout.my_collection,container,false); myBearsList = new ArrayList<>(); mMyBearsAdapter = new MyBearsMyCollectionAdapter(this, R.layout.one_my_Bear_in_my_collection_display, myBearsList); mMyBearsAdapter.add(new myBear(27, "Hi", 48)); mMyBearsAdapter.add(new myBear(4, "Hi", 87)); mMyBearsAdapter.add(new myBear(6, "Hi", 39)); mMyBearsAdapter.add(new myBear(8, "Hallo", 90)); mMyBearsAdapter.add(new myBear(0, "Hi", 28)); mMyBearsAdapter.add(new myBear(8, "Bye", 54)); //the grid view from this fragment mMyBearGridView = (GridView) v.findViewById(R.id.my_Bears_in_my_collection_grid_view); mMyBearGridView.setAdapter(mMyBearsAdapter); return v; } }：

ArrayAdapter

Answer 1

试试这个。

public class MyBear implements Comparable<MyBear>{  

    private int size;

    @Override  
    public int compareTo(MyBear mBear) {  
        //Edited here with your get value
        int i = this.size - mBear.getSize();

        return i;  
    }  
}

然后添加到您的java代码

    myBearsList = new ArrayList<>();
    myBearsList.add(new myBear(27, "Hi", 48));
    myBearsList.add(new myBear(4, "Hi", 87));
    myBearsList.add(new myBear(6, "Hi", 39));
    myBearsList.add(new myBear(8, "Hallo", 90));
    myBearsList.add(new myBear(0, "Hi", 28));
    myBearsList.add(new myBear(8, "Bye", 54));
    // edited here , add Collections
    Collections.sort(myBearsList);
    mMyBearsAdapter = new MyBearsMyCollectionAdapter(this, R.layout.one_my_Bear_in_my_collection_display, myBearsList);

注意

public class MyBear implements Comparable<MyBear>{}

使用compareTo方法

使用Collections.sort(myBearsList);

Answer 2

您可以在 MyBear pojo中实现Comparable，如下所示：

class MyBear implements Comparable<MyBear> {
   ... 
   int size;
   ...
   // Override compareTo method
   public int compareTo(MyBear myBear) {
     return this.size - myBear.getSize();
   }
   ...
}

然后使用Collections.sort()对其进行排序：

Collections.sort(myBearsList);

或者你可以使用Collection.sort()这样的东西来使用懒惰的方法：

Collections.sort(myBearsList, new Comparator<MyBear>() {
        @Override public int compare(MyBear o1, MyBear o2) {
          return NumberUtils.compare(o2.getSize(), o1.getSize());
        }
      });

这将首先对列表进行排序。您可以通过更改比较来反转排序。

Answer 3

因为我正在使用数据库并且不断在我的ArrayAdapter中添加对象， 1。我需要在MyBear中添加一个排序Comparator，如下所示： public static Comparator MyBearCreatedDateComparator = new Comparator（）{

    public int compare(MyBear myBear1, MyBear myBear2) {

        Long MyBearCreatedDate1 = myBear1.getBearCreatedDate();
        Long MyBearCreatedDate2 = myBear2.getBearCreatedDate();

        return MyBearCreatedDate2.compareTo(MyBearCreatedDate1);
    }

};

2. 每当我在ArrayAdapter中添加一个新对象时，我需要调用一个 3。并调用notifyDataSetChanged（）以便我的GridView / ListView刷新。像这样：

mMyBearsAdapter.add(myBear);
                        mMyBearsAdapter.sort(MyBear.MyBearCreatedDateComparator);
                        mMyBearsAdapter.notifyDataSetChanged();

我在GridView中使用ArrayAdapter和List。如何配置基于ArrayAdapter中的对象变量进行排序？

3 个答案: