如何像在新的GMail应用中一样实现“向下滑动以刷新”

Question

Google发行了新的Gmail应用程序，并通过另一种方式处理下拉刷新。

而不是显示下拉的开始的隐藏行。 Gmail在操作栏上方显示动画消息。

该消息包括一条动画水平线。

这是Android SDK的标准功能吗？ 我在操作栏API中找不到能做到这一点的任何东西。

Answer 1

Google已直接在SDK中发布了对此的支持。 我不确定您需要支持哪个版本（可能是一个问题）。

在此处查看官方的SDK功能信息： http ： //developer.android.com/reference/android/support/v4/widget/SwipeRefreshLayout.html

如果您能够使用SDK之一，那么即使Chris Banes撰写了一篇帖子 ，也暗示您会更好。

Answer 2

克里斯·班尼斯（Chris Banes）在GitHub上的ActionBar-PullToRefresh库可能提供了最接近GMail应用程序的即按即提功能。

另请参见： JuhaniLehtimäki对GMail的“按需刷新”分析 。

Answer 3

试试这个...对我有用。

RES /布局/activity_main.xml

 <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.swipetorefresh.MainActivity"
tools:ignore="MergeRootFrame" />

RES /布局/fragment_main.xml

<android.support.v4.widget.SwipeRefreshLayout           
       xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:tools="http://schemas.android.com/tools"
      android:id="@+id/container"
      android:layout_width="match_parent"
      android:layout_height="match_parent"
       tools:ignore="MergeRootFrame" >

   <ListView
      android:id="@android:id/list"
      android:layout_width="match_parent"
      android:layout_height="match_parent" />

</android.support.v4.widget.SwipeRefreshLayout>

MainActivity.java

  public class MainActivity extends Activity {

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

    if (savedInstanceState == null) {
        getFragmentManager().beginTransaction()
                .add(R.id.container, new PlaceholderFragment()).commit();
    }
}

public static class PlaceholderFragment extends ListFragment implements OnRefreshListener {

    private SwipeRefreshLayout mSwipeRefreshLayout;

    private static final int LIST_ITEM_COUNT = 5;
    private int mOffset = 0;

    private ArrayAdapter<String> mListAdapter;

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container,
                false);

        // Configure the swipe refresh layout
        mSwipeRefreshLayout = (SwipeRefreshLayout) rootView.findViewById(R.id.container);
        mSwipeRefreshLayout.setOnRefreshListener(this);
        mSwipeRefreshLayout.setColorScheme(
                R.color.swipe_color_1, R.color.swipe_color_2,
                R.color.swipe_color_3, R.color.swipe_color_4);

        // Put the first batch of countries in the list
        mListAdapter = new ArrayAdapter<String>(
                getActivity(),
                android.R.layout.simple_list_item_1,
                android.R.id.text1,
                getCountries(mOffset));

        setListAdapter(mListAdapter);

        return rootView;
    }

    private List<String> getCountries(int offset) {
        ArrayList<String> countriesList = new ArrayList<String>();
        for(int i=0; i<LIST_ITEM_COUNT;i++){
            countriesList.add(COUNTRIES[offset+i]);
        }

        mOffset = offset + LIST_ITEM_COUNT;
        return countriesList;
    }

    @Override
    public void onRefresh() {
        // Start showing the refresh animation
        mSwipeRefreshLayout.setRefreshing(true);

        // Simulate a long running activity
        new Handler().postDelayed(new Runnable() {
            @Override
            public void run() {
               updateCountries();
            }
        }, 5000);
    }



    private void updateCountries() {

        // Add the next batch of countries to the list
        mListAdapter.addAll(getCountries(mOffset));

        // Signify that we are done refreshing
        mSwipeRefreshLayout.setRefreshing(false);
    }



    private static final String[] COUNTRIES = {"Afghanistan",
        "Albania", "Algeria", "American Samoa", "Andorra", "Angola",
        "Anguilla", "Antarctica", "Antigua and Barbuda", "Argentina",
        "Armenia", "Aruba", "Australia", "Austria", "Azerbaijan",
        "Bahamas", "Bahrain", "Bangladesh", "Barbados", "Belarus",
        "Belgium", "Belize", "Benin", "Bermuda", "Bhutan",
        "Bolivia", "Bosnia and Herzegovina", "Botswana", "Brazil",
        "Brunei Darussalam", "Bulgaria", "Burkina Faso", "Burundi",
        "Cambodia", "Cameroon", "Canada", "Cape Verde", "Cayman Islands",
        "Central African Republic", "Chad", "Chile", "China",
        "Christmas Island", "Cocos (Keeling) Islands", "Colombia",
        "Comoros", "Democratic Republic of the Congo (Kinshasa)",
        "Congo, Republic of(Brazzaville)", "Cook Islands", "Costa Rica",
        "Ivory Coast", "Croatia", "Cuba", "Cyprus", "Czech Republic",
        "Denmark", "Djibouti", "Dominica", "Dominican Republic",
        "East Timor (Timor-Leste)", "Ecuador", "Egypt",
        "El Salvador", "Equatorial Guinea", "Eritrea", "Estonia", "Ethiopia"};

        }
   }

Answer 4

克里斯·班内斯（Chris Banes）（实现了Android最佳拉动刷新组件的同一个人）也实现了Gmail例如“拉动刷新”。

您可以在这里找到它： https : //github.com/chrisbanes/ActionBar-PullToRefresh

请注意，此项目仍在开发中，因此当前的API可能会更改。

Answer 5

fragment_main.xml

<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.example.testloading.MainActivity$PlaceholderFragment" >

  <ListView
      android:id="@+id/list"
      android:layout_width="match_parent"
      android:layout_height="match_parent" />

</RelativeLayout>    


counteries.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TextView 
        android:id="@+id/text_view"
        android:layout_width="match_parent"
        android:layout_height="47dp"
        android:gravity="center_vertical"
        android:textStyle="bold"/>
</LinearLayout>



package com.example.testloading;

import java.util.ArrayList;
import java.util.List;

import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.TextView;

public class MainActivity extends ActionBarActivity {

    private static final String TAG = MainActivity.class.getSimpleName();

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

        if (savedInstanceState == null) {
            getSupportFragmentManager().beginTransaction()
                    .add(R.id.container, new PlaceholderFragment()).commit();
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, 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();
        if (id == R.id.action_settings) {
            return true;
        }
        return super.onOptionsItemSelected(item);
    }

    /**
     * A placeholder fragment containing a simple view.
     */
    public static class PlaceholderFragment extends Fragment {

        private ListView listView;
        private static final int LIST_ITEM_COUNT = 20;
        private int mOffset = 0;
        private boolean flag_loading;

        private MyAdapter adapter;
        private List<String> list;

        public PlaceholderFragment() {
        }

        @Override
        public View onCreateView(LayoutInflater inflater, ViewGroup container,
                Bundle savedInstanceState) {
            View rootView = inflater.inflate(R.layout.fragment_main, container,
                    false);

            listView = (ListView) rootView.findViewById(R.id.list);
            list = getCountries(mOffset);
            adapter = new MyAdapter(list, getActivity());
            listView.setAdapter(adapter);
            listView.setOnScrollListener(new OnScrollListener() {

                @Override
                public void onScrollStateChanged(AbsListView view,
                        int scrollState) {
                }

                @Override
                public void onScroll(AbsListView view, int firstVisibleItem,
                        int visibleItemCount, int totalItemCount) {
                    Log.d(TAG, "firstVisibleItem : " + firstVisibleItem
                            + " , visibleItemCount : " + visibleItemCount
                            + " , totalItemCount : " + totalItemCount);
                    if (firstVisibleItem + visibleItemCount == totalItemCount) {
                        Log.d(TAG, "ZZZ offSet : " + mOffset);
                        if (COUNTRIES.length > mOffset) {
                            if (flag_loading == false) {
                                Log.d(TAG, "ZZZ inside : ");
                                flag_loading = true;
                                additems();
                            }
                        }
                    }

                }
            });
            return rootView;
        }

        protected void additems() {
            list.addAll(getCountries(mOffset));
            adapter.notifyDataSetChanged();
            listView.invalidate();
            flag_loading = false;
        }

        private List<String> getCountries(int offset) {
            ArrayList<String> countriesList = new ArrayList<String>();
            for (int i = 0; i < LIST_ITEM_COUNT; i++) {
                if (COUNTRIES.length > offset + i) {
                    countriesList.add(COUNTRIES[offset + i]);
                }
            }

            mOffset = offset + LIST_ITEM_COUNT;
            return countriesList;
        }

        private static final String[] COUNTRIES = { "Afghanistan", "Albania",
                "Algeria", "American Samoa", "Andorra", "Angola", "Anguilla",
                "Antarctica", "Antigua and Barbuda", "Argentina", "Armenia",
                "Aruba", "Australia", "Austria", "Azerbaijan", "Bahamas",
                "Bahrain", "Bangladesh", "Barbados", "Belarus", "Belgium",
                "Belize", "Benin", "Bermuda", "Bhutan", "Bolivia",
                "Bosnia and Herzegovina", "Botswana", "Brazil",
                "Brunei Darussalam", "Bulgaria", "Burkina Faso", "Burundi",
                "Cambodia", "Cameroon", "Canada", "Cape Verde",
                "Cayman Islands", "Central African Republic", "Chad", "Chile",
                "China", "Christmas Island", "Cocos (Keeling) Islands",
                "Colombia", "Comoros",
                "Democratic Republic of the Congo (Kinshasa)",
                "Congo, Republic of(Brazzaville)", "Cook Islands",
                "Costa Rica", "Ivory Coast", "Croatia", "Cuba", "Cyprus",
                "Czech Republic", "Denmark", "Djibouti", "Dominica",
                "Dominican Republic", "East Timor (Timor-Leste)", "Ecuador",
                "Egypt", "El Salvador", "Equatorial Guinea", "Eritrea",
                "Estonia", "Ethiopia" };

    }
}

class MyAdapter extends BaseAdapter {

    private List<String> list;
    private LayoutInflater layoutInflater;

    public MyAdapter(List<String> list, Context context) {
        this.list = list;
        layoutInflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    }

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

    @Override
    public Object getItem(int position) {
        return list.get(position);
    }

    @Override
    public long getItemId(int arg0) {
        // TODO Auto-generated method stub
        return 0;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup arg2) {

        ViewHolder viewHolder;

        if (convertView == null) {
            convertView = layoutInflater.inflate(R.layout.counteries, null);
            viewHolder = new ViewHolder();
            viewHolder.textView = (TextView) convertView
                    .findViewById(R.id.text_view);
            convertView.setTag(viewHolder);
        } else {
            viewHolder = (ViewHolder) convertView.getTag();
        }

        viewHolder.textView.setText(list.get(position));
        return convertView;
    }

    class ViewHolder {
        public TextView textView;
    }
}

Answer 6

测试一下。 使用：swipeRefreshLayout.setRotation（180f）;

在您的适配器ListView中，使用方法getView：view.setRotation（180f）;

反转列表中商品的顺序。

或直接在xml中使用android：rotation =“ 180”。