发布于 2017-09-18 21:48:53 | 69 次阅读 | 评论: 0 | 来源: 网友投递

这里有新鲜出炉的精品教程,程序狗速度看过来!

Android移动端操作系统

Android是一种基于Linux的自由及开放源代码的操作系统,主要使用于移动设备,如智能手机和平板电脑,由Google公司和开放手机联盟领导及开发。尚未有统一中文名称,中国大陆地区较多人使用“安卓”或“安致”。


这篇文章主要介绍了Android基于ListView实现类似Market分页加载效果,结合完整实例形式分析了ListView的OnScroll方法来实现分页与滚动加载的操作步骤与相关实现技巧,需要的朋友可以参考下

本文实例讲述了Android基于ListView实现类似Market分页加载效果。分享给大家供大家参考,具体如下:

最近几天研究ListView实现分页加载和滚动加载,发现可以用listView的OnScroll方法来实现,直接上代码

ListViewScroll.java


package zy.lucifer.ListViewScroll;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.BaseAdapter;
import android.widget.LinearLayout;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.AbsListView.OnScrollListener;
import android.widget.LinearLayout.LayoutParams;
public class ListViewScroll extends Activity {
  /** Called when the activity is first created. */
  private LayoutParams mLayoutParams = new LinearLayout.LayoutParams(
      LinearLayout.LayoutParams.WRAP_CONTENT,
      LinearLayout.LayoutParams.WRAP_CONTENT);
  /**
   * 设置布局显示目标最大化属性
   */
  private LayoutParams FFlayoutParams = new LinearLayout.LayoutParams(
      LinearLayout.LayoutParams.FILL_PARENT,
      LinearLayout.LayoutParams.FILL_PARENT);
  ListView listView ;
  private int lastItem = 0;
  LinearLayout loadingLayout;
  private listViewAdapter adapter;
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    listView = (ListView) findViewById(R.id.myList);
    Log.i("test", "onCreate(Bundle savedInstanceState)>>>>>>>>>>>>>>>");
    // 线性布局
    LinearLayout layout = new LinearLayout(this);
    // 设置布局 水平方向
    layout.setOrientation(LinearLayout.HORIZONTAL);
    // 进度条
    ProgressBar progressBar = new ProgressBar(this);
    // 进度条显示位置
    progressBar.setPadding(0, 0, 15, 0);
    // 把进度条加入到layout中
    layout.addView(progressBar, mLayoutParams);
    // 文本内容
    TextView textView = new TextView(this);
    textView.setText("加载中...");
    textView.setGravity(Gravity.CENTER_VERTICAL);
    // 把文本加入到layout中
    layout.addView(textView, FFlayoutParams);
    // 设置layout的重力方向,即对齐方式是
    layout.setGravity(Gravity.CENTER);
    // 设置ListView的页脚layout
    loadingLayout = new LinearLayout(this);
    loadingLayout.addView(layout, mLayoutParams);
    loadingLayout.setGravity(Gravity.CENTER);
    listView.addFooterView(loadingLayout);
    adapter = new listViewAdapter();
    listView.setAdapter(adapter);
    listView.setOnScrollListener(new OnScrollListener() {
      @Override
      public void onScroll(AbsListView view, int firstVisibleItem,
          int visibleItemCount, int totalItemCount) {
        // TODO Auto-generated method stub
        Log.i("test" , "Scroll>>>first: " + firstVisibleItem + ", visible: " + visibleItemCount + ", total: " + totalItemCount);
        lastItem = firstVisibleItem + visibleItemCount - 1;
        Log.i("test" , "Scroll>>>lastItem:" + lastItem);
        //显示50条ListItem,即0-49,因为onScroll是在“滑动”执行过之后才触发,所以用adapter.count<=41作条件
        int scrolllength=101;
        if (adapter.count<=scrolllength) {
          if (firstVisibleItem+visibleItemCount==totalItemCount) {
            adapter.count += 10;
            adapter.notifyDataSetChanged();
            listView.setSelection(lastItem);
            int currentPage=adapter.count/10;
            Toast.makeText(getApplicationContext(), "第"+currentPage+"页", Toast.LENGTH_LONG).show();
          }
        }
        else {
           listView.removeFooterView(loadingLayout);
        }
      }
      @Override
      public void onScrollStateChanged(AbsListView view, int scrollState) {
        // TODO Auto-generated method stub
      }
    });
  }
  class listViewAdapter extends BaseAdapter {
    int count = 10; /* starting amount */
    public int getCount() {
      return count;
    }
    public Object getItem(int pos) {
      return pos;
    }
    public long getItemId(int pos) {
      return pos;
    }
    public View getView(int pos, View v, ViewGroup p) {
      Log.i("test", "getView>>>pos:" + pos);
      TextView view;
      if (v == null) {
        view = new TextView(ListViewScroll.this);
      } else {
        view = (TextView) v;
      }
      view.setText("ListItem " + pos);
      view.setTextSize(20f);
      view.setGravity(Gravity.CENTER);
      view.setHeight(60);
      return view;
    }
  }
}

main.xml


<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  >
<ListView android:cacheColorHint="#00000000" android:id="@+id/myList"
android:layout_width="fill_parent" android:layout_height="fill_parent"
    >
  </ListView>
</LinearLayout>

希望本文所述对大家Android程序设计有所帮助。



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