Fragment数据传递与数据回显

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http://blog.csdn.net/a254830856/article/details/51569425

实现效果：当滑动ListView列表最底端时，动态的添加新的列表项

实现步骤：

调用ListView的setOnScrollListener()方法设置滑动监听器，实现OnScrollListener接口的方法

判断当列表滑动到最低端时，加载新的列表项

接口OnScrollListener

onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount)

view 报告滑动状态的视图

firstVisibleItem 可视的第一个列表项的索引

visibleItemCount 可视的列表项个数

totalItemCount 总共的列表项个数

onScrollStateChanged(AbsListView view, int scrollState)

view 报告滑动状态的视图

scrollState 滑动状态

滑动状态

SCROLL_STATE_IDLE : 0 视图没有滑动

SCROLL_STATE_TOUCH_SCROLL : 1 用户正在触摸滑动，手指仍在屏幕上

SCROLL_STATE_FLING : 2 用户之前触摸滑动，现在正在滑行，直到停止

示例代码：

Java代码  
package dyingbleed.iteye;  
  
import android.app.ListActivity;  
import android.os.Bundle;  
import android.os.Handler;  
import android.os.Message;  
import android.view.Gravity;  
import android.view.LayoutInflater;  
import android.view.View;  
import android.view.ViewGroup;  
import android.widget.AbsListView;  
import android.widget.BaseAdapter;  
import android.widget.ListView;  
import android.widget.TextView;  
  
public class Main extends ListActivity {  
      
    private ListView listView;  
    private MyListViewAdapter adapter;  
      
    private int scrollState;  
      
    private View footerView;  
      
    @Override  
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.main);  
          
        listView = getListView();  
          
        footerView = LayoutInflater.from(this).inflate(R.layout.progress, null);  
                  
        listView.addFooterView(footerView); //在ListView底部添加正在加载视图    
        //注意：addFooterView方法需要在调用setListAdapter方法前调用！  
        adapter = new MyListViewAdapter();  
        setListAdapter(adapter);  
        getListView().setOnScrollListener(new AbsListView.OnScrollListener() {  
              
            @Override  
            public void onScrollStateChanged(AbsListView view, int scrollState) {  
                Main.this.scrollState = scrollState;  
            }  
              
            @Override  
            public void onScroll(AbsListView view, int firstVisibleItem,  
                    int visibleItemCount, int totalItemCount) {  
                int lastVisibleItem = firstVisibleItem + visibleItemCount - 1; //可视的最后一个列表项的索引  
                /* 
                 * 当列表正处于滑动状态且滑动到列表底部时，执行 
                 * */  
                if(Main.this.scrollState != AbsListView.OnScrollListener.SCROLL_STATE_IDLE  
                        && lastVisibleItem == totalItemCount - 1) {  
                    /* 
                     * 执行线程，睡眠5秒钟后添加10个列表项 
                     * */  
                    new Thread() {  
                          
                        private Handler handler = new Handler() {  
  
                            @Override  
                            public void handleMessage(Message msg) {  
                                super.handleMessage(msg);  
                                adapter.count += 10;  
                                adapter.notifyDataSetChanged();  
                            }  
                              
                        };  
  
                        @Override  
                        public void run() {  
                            super.run();  
                            try {  
                                sleep(5000);  
                                handler.sendEmptyMessage(0);  
                            } catch (InterruptedException e) {  
                                e.printStackTrace();  
                            }  
                        }  
                          
                    }.start();  
                      
                }  
            }  
        });  
    }  
      
    private class MyListViewAdapter extends BaseAdapter {  
          
        int count = 50; //初始列表项数量  
  
        @Override  
        public int getCount() {  
            return count;  
        }  
  
        @Override  
        public Object getItem(int position) {  
            return position;  
        }  
  
        @Override  
        public long getItemId(int position) {  
            return position;  
        }  
  
        @Override  
        public View getView(int position, View convertView, ViewGroup parent) {  
            TextView result = (TextView) convertView;  
            if(result == null) {  
                result = new TextView(Main.this);  
                result.setTextAppearance(Main.this, android.R.style.TextAppearance_Large);  
                AbsListView.LayoutParams layoutParams = new AbsListView.LayoutParams(AbsListView.LayoutParams.FILL_PARENT,  
                        AbsListView.LayoutParams.WRAP_CONTENT);  
                result.setLayoutParams(layoutParams);  
                result.setGravity(Gravity.CENTER);  
            }  
            result.setText("Item "+(position+1));  
            return result;  
        }  
          
    }  
}  

运行结果

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