ListView动态加载数据模板（使用代码布局）

From 同站：  http://blog.csdn.net/qeqeqe236/article/details/7289125

对于做Android应用程序来说，ListView一定用得非常多，经常解析xml文件然后在ListView中显示，往往我们需要让它动态地加载内容，也就是不一次性地加载完成，对于手机来说，这点很重要！

笔者之前也是弄的不明白，用的时候直接在网上找代码，复制粘贴，再修改一下就是自己的了，笔者的这个小Demo灵感来自于新浪或者腾讯微博手机客户端，比如第一页加载十条Item，当翻到最后一个Item的时候，会出来一个Button，当点击Button的时候就会继续加载更多的，当然如果不点，就不会加载的，节约用户流量，先看效果图

OK，如果觉得满意的话就继续看下面的代码吧，笔者这里没有用到main.xml文件，全部在java文件中定义的，如果理解了的话自己可以在xml文件里面写布局

package com.focus.loading;

import android.app.ListActivity;

import android.os.Bundle;

import android.os.Handler;

import android.view.Gravity;

import android.view.View;

import android.view.View.OnClickListener;

import android.view.ViewGroup;

import android.view.ViewGroup.LayoutParams;

import android.widget.AbsListView;

import android.widget.AbsListView.OnScrollListener;

import android.widget.BaseAdapter;

import android.widget.Button;

import android.widget.LinearLayout;

import android.widget.ListView;

import android.widget.ProgressBar;

import android.widget.TextView;

public class ListViewActivity extends ListActivity implements OnScrollListener {

private LinearLayout mLoadLayout;

private LinearLayout mProgressLoadLayout;

private ListView mListView;

private ListViewAdapter mListViewAdapter = new ListViewAdapter();

private int mLastItem = 0;

private int mCount = 41;

private final Handler mHandler = new Handler();// 在Handler中加载数据

private final LayoutParams mLayoutParams = new LinearLayout.LayoutParams(

LinearLayout.LayoutParams.WRAP_CONTENT,

LinearLayout.LayoutParams.WRAP_CONTENT);

int scrollState;// 全局变量，用来记录ScrollView的滚动状态，1表示开始滚动，2表示正在滚动，0表示滚动停止

int visibleItemCount;// 当前可见页面中的Item总数

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

/**

* "加载项"布局，此布局被添加到ListView的Footer中。

*/

mLoadLayout = new LinearLayout(this);

mLoadLayout.setMinimumHeight(30);

mLoadLayout.setGravity(Gravity.CENTER);

mLoadLayout.setOrientation(LinearLayout.VERTICAL);

/*

* 当点击按钮的时候显示这个View，此View使用水平方式布局，左边是一个进度条，右边是文本，默认设为不可见

*/

mProgressLoadLayout = new LinearLayout(this);

mProgressLoadLayout.setMinimumHeight(30);

mProgressLoadLayout.setGravity(Gravity.CENTER);

mProgressLoadLayout.setOrientation(LinearLayout.HORIZONTAL);

ProgressBar mProgressBar = new ProgressBar(this);

mProgressBar.setPadding(0, 0, 15, 0);

mProgressLoadLayout.addView(mProgressBar, mLayoutParams);// 为布局添加进度条

TextView mTipContent = new TextView(this);

mTipContent.setText("加载中...");

mProgressLoadLayout.addView(mTipContent, mLayoutParams);// 为布局添加文本

mProgressLoadLayout.setVisibility(View.GONE);// 默认设为不可见，注意View.GONE和View.INVISIBLE的区别

mLoadLayout.addView(mProgressLoadLayout);// 把之前的布局以View对象添加进来

final Button button = new Button(this);

button.setText("加载更多");

// 添加按钮

mLoadLayout.addView(button, new LayoutParams(LayoutParams.FILL_PARENT,

LayoutParams.WRAP_CONTENT));

button.setOnClickListener(new OnClickListener() {

@Override

public void onClick(View v) {

if (mLastItem == mListViewAdapter.count

&& scrollState == OnScrollListener.SCROLL_STATE_IDLE) {

// 当点击时把带进度条的Layout设为可见，把Button设为不可见

mProgressLoadLayout.setVisibility(View.VISIBLE);

button.setVisibility(View.GONE);

if (mListViewAdapter.count <= mCount) {

mHandler.postDelayed(new Runnable() {

@Override

public void run() {

mListViewAdapter.count += 10;

mListViewAdapter.notifyDataSetChanged();

mListView.setSelection(mLastItem

- visibleItemCount + 1);

// 获取数据成功时把Layout设为不可见，把Button设为可见

mProgressLoadLayout.setVisibility(View.GONE);

button.setVisibility(View.VISIBLE);

}

}, 2000);

}

}

}

});

mListView = getListView();

mListView.addFooterView(mLoadLayout);

setListAdapter(mListViewAdapter);

mListView.setOnScrollListener(this);

}

@Override

public void onScroll(AbsListView view, int firstVisibleItem,

int visibleItemCount, int totalItemCount) {

this.visibleItemCount = visibleItemCount;

mLastItem = firstVisibleItem + visibleItemCount - 1;

if (mListViewAdapter.count > mCount) {

mListView.removeFooterView(mLoadLayout);

}

}

@Override

public void onScrollStateChanged(AbsListView view, int scrollState) {

this.scrollState = scrollState;

}

class ListViewAdapter extends BaseAdapter {

int count = 10;

public int getCount() {

return count;

}

public Object getItem(int position) {

return position;

}

public long getItemId(int position) {

return position;

}

public View getView(int position, View view, ViewGroup parent) {

TextView mTextView;

if (view == null) {

mTextView = new TextView(ListViewActivity.this);

} else {

mTextView = (TextView) view;

}

mTextView.setText("Item " + position);

mTextView.setTextSize(20f);

mTextView.setGravity(Gravity.CENTER);

mTextView.setHeight(60);

return mTextView;

}

}

}