网络取图片先取先显示

1、新建一个XML，定义按钮点击按钮开始取图片：

<?x ml 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" >
    
<ImageView 
    android:id="@+id/imgview"
    android:layout_width="wrap_content"
    android:layout_height="80dp"/>
</LinearLayout>

2、创建一个Activty继承Activty

package com.scxh.netwangqu.gridview;

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.List;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.GridView;

import com.scxh.netwangqu.R;

public class MainActivity extends Activity {
  //定义网址
  private String http[] = {
      "http://www.iyi8.com/uploadfile/2014/1215/20141215113901749.jpg",
      "http://www.iyi8.com/uploadfile/2014/1209/20141209112742464.jpg",
      "http://www.juxia.com/uploadfile/content/2012/2/20120210163653221.jpg",
      "http://www.58game.cn/static/uploads/news/20130323/514d6f9c6c327.jpg",
      "http://pic.zznews.cn/0/10/09/24/10092439_941510.jpg",
      "http://ww2.sinaimg.cn/mw600/a8e0a0d3tw1e2luctga7cj.jpg",
      "http://ww2.sinaimg.cn/bmiddle/6ba10ddagw1dwtr9f55onj.jpg",
      "http://picview01.baomihua.com/photos/20120731/m_14_634793365268750000_14191008.jpg",
      "http://www.gscn.com.cn/pic/0/10/05/62/10056208_236741.jpg",
      "http://www.eeyy.com/uploadfile/2012/0319/20120319104210914.jpg",
      "http://images.55bbs.com/55shuoimg/pic/11/08/2c/11082cda8aac14fce6e72da19746f726.jpg",
      "http://cdn.t01.pic.sogou.com/3c28af542f2d49f7-f1ff85e490dc165f-062f5376e12039640d826e8667d7feaa.jpg" };
  private Button mButton;
  private GridView mGridView;
  MyBasaAdaper myadapter;
  ArrayList mlist = new ArrayList();

  Handler handle = new Handler();

  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    mButton = (Button) findViewById(R.id.gridbtn);
    mGridView = (GridView) findViewById(R.id.gridv);

    myadapter = new MyBasaAdaper(this);
    mGridView.setAdapter(myadapter);

    // myadapter.setData(getData());

    mButton.setOnClickListener(new OnClickListener() {

      @Override
      public void onClick(View v) {
        // ThreadfZ();
        myadapter.setData(http);
      }
    });

  }

  // 封装线程
  public void ThreadfZ() {

    Thread t = new Thread(new Runnable() {

      @Override
      public void run() {
        InputStream inputStream = null;
        URL url = null;
        // 用while循环取图片
        int i = 0;
        while (i < http.length) {
          try {
            url = new URL(http[i++]);
          } catch (MalformedURLException e1) {
            e1.printStackTrace();
          }
          try {
            // 打开流
            inputStream = url.openStream();
          } catch (IOException e) {
            e.printStackTrace();
          }

          Bitmap bitmap = BitmapFactory.decodeStream(inputStream);
          // 把取出的图片fangr
          mlist.add(bitmap);

          Log.e("list", mlist + "");

        }
        handle.post(new Runnable() {

          @Override
          public void run() {

            // myadapter.setData(mlist);
          }
        });

      }
    });
    t.start();
  }

}

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3、定义适配器Adaper继承BaseAdapter 

package com.scxh.netwangqu.gridview;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.List;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;

import com.scxh.netwangqu.R;

public class MyBasaAdaper extends BaseAdapter {
  private String[] mList = new String[] {};

  private LayoutInflater mInflater;
  private Context mcontext;

  public MyBasaAdaper(Context context) {
    mcontext = context;
    mInflater = LayoutInflater.from(mcontext);

  }

  public void setData(String[] mlist) {
    mList = mlist;
    notifyDataSetChanged();
  }

  @Override
  public int getCount() {

    return mList.length;
  }

  @Override
  public Object getItem(int position) {

    return (String) mList[position];
  }

  @Override
  public long getItemId(int position) {

    return position;
  }

  @Override
  public View getView(int position, View convertView, ViewGroup parent) {
    convertView = mInflater.inflate(R.layout.gridimgview, null);
    final ImageView iconImg = (ImageView) convertView
        .findViewById(R.id.imgview);
    new AsyncTask<String, Void, Bitmap>() {

      @Override
      protected Bitmap doInBackground(String... params) {
        String httpUrl = (String) params[0]; // http://www.xx/mm.jpg
        Bitmap bitmap = null;
        URL url = null;
        InputStream is = null;
        InputStream inputStream;
        try {
          url = new URL(httpUrl);
          inputStream = url.openStream();
          bitmap = BitmapFactory.decodeStream(inputStream);
        } catch (MalformedURLException e1) {
          e1.printStackTrace();
        } catch (IOException e) {
          e.printStackTrace();
        } finally {
          if (is != null) {
            try {
              is.close();
            } catch (IOException e) {

              e.printStackTrace();
            }
          }
        }

        return bitmap;
      }

      @Override
      protected void onPostExecute(Bitmap bitmap) {
        super.onPostExecute(bitmap);
        iconImg.setImageBitmap(bitmap);
      }
    }.execute(mList[position]);

    return convertView;
  }

  class ViewHolder {
    ImageView iconImg = null;

  }

}