android基础--列表项添加进度框

ListView、GridView列表项中清加ProgressBar,这里用最简单的代码实现可以通用的功能

如果你的适配器getView方法返回的View是一个自定义控件的话，有点不好实现哦，不过可以用两个控件之间Visible 、Invisible来切换实现今天的效果

下面的例子是主类、适配器、异步下载类等的都写在一个类里面了，其它控件列表项中添加进度框大家也可以用如下的方法实现

一：效果图如下

核心代码如下：

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package com.example.listviewitemprogress;

import java.io.InputStream;

import java.net.HttpURLConnection;

import java.net.URL;

import android.app.Activity;

import android.content.Context;

import android.graphics.Bitmap;

import android.graphics.BitmapFactory;

import android.os.AsyncTask;

import android.os.Bundle;

import android.view.LayoutInflater;

import android.view.View;

import android.view.ViewGroup;

import android.widget.BaseAdapter;

import android.widget.Button;

import android.widget.ImageView;

import android.widget.ListView;

import android.widget.ProgressBar;

import android.widget.TextView;

/**

* ListView列表项中添加ProgressBar

public class MainActivity extends Activity

{

private ListView mListView = null ;

private static final String imgUrl = "http://www.qq510.net/uploads/allimg/100613/2_100613171230_5.jpg";

@Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

init();

}

private void init(){

mListView = (ListView)findViewById(R.id.listview);

mListView.setAdapter(new MyListViewAdapter(this));

}

private class MyListViewAdapter extends BaseAdapter

{

private LayoutInflater inflater = null;

public MyListViewAdapter(Context con){

inflater = (LayoutInflater)con.getSystemService(LAYOUT_INFLATER_SERVICE);

}

@Override

public int getCount() {

// TODO Auto-generated method stub

return Integer.MAX_VALUE;

}

@Override

public Object getItem(int arg0) {

// TODO Auto-generated method stub

return arg0;

}

@Override

public long getItemId(int position)

{

// TODO Auto-generated method stub

return position;

}

@Override

public View getView(int position, View convertView, ViewGroup parent)

{

// TODO Auto-generated method stub

ViewHolder mHolder = new ViewHolder() ;

if(convertView == null)

{

convertView = inflater.inflate(R.layout.list_item, null);

mHolder.iv = (ImageView)(convertView.findViewById(R.id.iv));

mHolder.mBtn = (Button)(convertView.findViewById(R.id.button));

mHolder.pb = (ProgressBar)(convertView.findViewById(R.id.progressBar1));

mHolder.tv = (TextView)(convertView.findViewById(R.id.textView1));

convertView.setTag(mHolder);

}else{

mHolder = (ViewHolder)convertView.getTag();

}

new AsyncTask<ViewHolder, Void, Bitmap>()

{

private ViewHolder v;

@Override

protected Bitmap doInBackground(ViewHolder... params) {

v = params[0];

return BitmapFactory.decodeStream(getStreamFromURL(imgUrl));

}

@Override

protected void onPostExecute(Bitmap result) {

super.onPostExecute(result);

v.pb.setVisibility(View.GONE);

v.mBtn.setVisibility(View.VISIBLE);

v.iv.setImageBitmap(result);

}

}.execute(mHolder);

return convertView;

}

static class ViewHolder{

ImageView iv = null ;

Button mBtn = null ;

ProgressBar pb = null ;

TextView tv = null ;

}

static String length;

public static InputStream getStreamFromURL(String imageURL)

{

InputStream in=null;

try {

URL url=new URL(imageURL);

HttpURLConnection connection=(HttpURLConnection) url.openConnection();

// connection.setRequestProperty("Connection", "Keep-Alive");//维持长连接

connection.setConnectTimeout(6* 1000);//设置连接超时

if (connection.getResponseCode() != 200) throw new RuntimeException("请求失败");

length = connection.getHeaderField("Content-Length");

in=connection.getInputStream();

} catch (Exception e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

return in;

}

布局：

主布局文件：

<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" >

<ListView

android:id="@+id/listview"

android:layout_width="fill_parent"

android:layout_height="fill_parent"

android:drawSelectorOnTop="false"

android:choiceMode="none"

android:focusable="false"

android:scrollingCache="false"

android:fadingEdge="none"

android:focusableInTouchMode="false"

android:clickable="false"

android:dividerHeight="0.5dip" />

</RelativeLayout>

ListView列表控件Item布局：

<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="110dp"

android:background="#00ffeeaa"

<ImageView

android:id="@+id/iv"

android:layout_width="110dp"

android:background="@drawable/ic_action_search"

android:layout_height="110dp"

android:contentDescription="@string/hello_world"/>

<Button

android:id="@+id/button"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentRight="true"

android:layout_centerVertical="true"

android:text="@string/xiaomaguo"/>

<ProgressBar

android:id="@+id/progressBar1"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignParentLeft="true"

android:layout_centerVertical="true"

android:layout_alignTop="@+id/button"

android:layout_marginLeft="29dp" />

<TextView

android:id="@+id/textView1"

android:layout_width="wrap_content"

android:layout_height="wrap_content"

android:layout_alignBaseline="@+id/button"

android:layout_alignBottom="@+id/button"

android:layout_centerVertical="true"

android:layout_toLeftOf="@+id/button"

android:text="@string/cool" />

</RelativeLayout>

所需权限：

<uses-permission android:name=”android.permission.INTERNET”/>

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android基础--列表项添加进度框

核心代码如下：

布局：

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