Listview加载网络数据、图片并跳转传值

来源：互联网发布：信息技术软件介绍ppt 编辑：程序博客网时间：2024/05/16 14:50

1、自定义Adapter，里面有一个Imageview跟三个Textview，其中只有两个Textview是显示出来的，另一个是不显示，用来存值，将这个值传递到跳转的界面的：

public class LvImageAdapter extends BaseAdapter {private ArrayList<String> mArrayList,mArrayList1,mArrayList2,mArrayList3;private Context mContext;private static Handler mHandler;private static LruCache<String, Bitmap> mCache;private ListView mListView;public LvImageAdapter(ArrayList<String> arrayList , ArrayList<String> arrayList1,         ArrayList<String> arrayList2,ArrayList<String> arrayList3,Context context, ListView listView) {this.mArrayList = arrayList;this.mArrayList1 = arrayList1;this.mArrayList2 = arrayList2;this.mArrayList3 = arrayList3;mContext = context;mHandler = new Handler();int maxSize = (int) (Runtime.getRuntime().maxMemory() / 1024);mCache = new LruCache<String, Bitmap>(maxSize / 2);mListView = listView;   }@Overridepublic int getCount() {return mArrayList.size();   }@Overridepublic String getItem(int arg0) {return mArrayList.get(arg0);   }@Overridepublic long getItemId(int arg0) {return arg0;   }public int getCount1() {return mArrayList1.size();   }public String getItem1(int arg1) {return mArrayList1.get(arg1);   }public long getItemId1(int arg1) {return arg1;   }public int getCount2() {return mArrayList2.size();   }public String getItem2(int arg2) {return mArrayList2.get(arg2);   }public long getItemId2(int arg2) {return arg2;   }public int getCount3() {return mArrayList3.size();   }public String getItem3(int arg1) {return mArrayList3.get(arg1);   }@Overridepublic View getView(int position, View convertView, ViewGroup arg2) {      ViewHolder holder;      convertView = View.inflate(mContext, R.layout.image_item, null);      holder = new ViewHolder();      holder.imageView = (ImageView) convertView.findViewById(R.id.imageView);      holder.textView1 = (TextView) convertView.findViewById(R.id.textView1);      holder.textView2 = (TextView) convertView.findViewById(R.id.textView2);      holder.textview00 = (TextView) convertView.findViewById(R.id.textview00);      convertView.setTag(holder);if (convertView == null) {         convertView = View.inflate(mContext, R.layout.image_item, null);         holder = new ViewHolder();         holder.imageView = (ImageView) convertView.findViewById(R.id.imageView);         holder.textView1 = (TextView) convertView.findViewById(R.id.textView1);         holder.textView2 = (TextView) convertView.findViewById(R.id.textView2);         holder.textview00 = (TextView) convertView.findViewById(R.id.textview00);         convertView.setTag(holder);      }else{         holder = (ViewHolder) convertView.getTag();      }//download imageholder.imageView.setImageResource(R.mipmap.download);      holder.imageView.setScaleType(ScaleType.FIT_XY);      holder.textView1.setText(mArrayList1.get(position));      holder.textView2.setText(mArrayList2.get(position));      holder.textview00.setText(mArrayList3.get(position));      holder.textview00.setVisibility(View.GONE);      Utils.loadImageFromUrl(mArrayList.get(position),mHandler, holder.imageView, mCache, mListView, position);      Log.i("LvImageAdapter", position+"");return convertView;   }    static class ViewHolder{private ImageView imageView;private TextView textView1,textView2,textview00;   }}

2、下载图片的类：

public class Utils {public static void loadImageFromUrl(final String url, final Handler handler, final ImageView imageView, final LruCache<String, Bitmap> lruCache, final ListView listView, final int position){if (lruCache.get(url) == null) {new Thread(new Runnable() {@Overridepublic void run() {final DefaultHttpClient client = new DefaultHttpClient();final HttpGet getRequest = new HttpGet(url);                 HttpResponse response = null;try {                  response = client.execute(getRequest);               } catch (ClientProtocolException e) {                  e.printStackTrace();               } catch (IOException e) {                  e.printStackTrace();               }int statusCode = response.getStatusLine().getStatusCode();if (statusCode != HttpStatus.SC_OK)  {                     Log.e("PicShow", "Request URL failed, error code =" + statusCode);                 }                 HttpEntity entity = response.getEntity();if (entity == null) {                     Log.e("PicShow", "HttpEntity is null");                 }                 InputStream is = null;                 ByteArrayOutputStream baos = new ByteArrayOutputStream();try {                     is = entity.getContent();byte[] buf = new byte[1024];int readBytes = -1;while ((readBytes = is.read(buf)) != -1) {                         baos.write(buf, 0, readBytes);                     }                 } catch (IllegalStateException e) {                  e.printStackTrace();               } catch (IOException e) {                  e.printStackTrace();               } finally {if (baos != null) {try {                        baos.close();                     } catch (IOException e) {                        e.printStackTrace();                     }                     }if (is != null) {try {                        is.close();                     } catch (IOException e) {                        e.printStackTrace();                     }                     }                 }byte[] imageArray = baos.toByteArray();final Bitmap bitmap = BitmapFactory.decodeByteArray(                         imageArray, 0, imageArray.length);handler.post(new Runnable() {@Overridepublic void run() {imageView.setImageBitmap(bitmap);lruCache.put(url, bitmap);                  }               });            }         }).start();      }else{         handler.post(new Runnable() {@Overridepublic void run() {imageView.setImageBitmap(lruCache.get(url));//listView.smoothScrollToPosition(position + 1);}         });       }   }public static void setListViewHeightBasedOnChildren(ListView listView) {        ListAdapter listAdapter = listView.getAdapter();if (listAdapter == null) {return;        }int totalHeight = 0;for (int i = 0; i < listAdapter.getCount(); i++) {         View listItem = listAdapter.getView(i, null, listView);         listItem.measure(0, 0);         totalHeight += listItem.getMeasuredHeight();        }        ViewGroup.LayoutParams params = listView.getLayoutParams();        params.height = totalHeight          + (listView.getDividerHeight() * (listAdapter.getCount() - 1));        listView.setLayoutParams(params);   }}

3、请求服务器，解析Json，得到数组，将数据加载到Listview中，传入的值包括三个显示的，还有一个不显示的：

Handlerhandler = new Handler() {public void handleMessage(Message msg) {switch (msg.what) {case 0:mArrayList = new ArrayList<String>();mArrayList1 = new ArrayList<String>();mArrayList2 = new ArrayList<String>();mArrayList3 = new ArrayList<String>();try {final String status = jsonObject.getString("status");if ("true".equals(status)) {jsonArray = jsonObject.getJSONArray("results");for (int i = 0; i < jsonArray.length(); i++) {item1 = jsonArray.getJSONObject(i);title = item1.getString("title");info = item1.getString("info");imageurl = item1.getString("img");myid = item1.getInt("id");mArrayList.add(imageurl);mArrayList1.add(title);mArrayList2.add(info);mArrayList3.add(myid+"");                        }                        LvImageAdapter lvImageAdapter = newLvImageAdapter(mArrayList, mArrayList1, mArrayList2,mArrayList3, OperateActivity.this, main_operate_listview);main_operate_listview.setAdapter(lvImageAdapter);main_operate_listview.setOnItemClickListener(new AdapterView.OnItemClickListener() {@Overridepublic void onItemClick(AdapterView<?> parent, View view,int position, long id) {        String str = mArrayList3.get(position);        Intent intent = new Intent();        intent.putExtra("ArticleNum", str);                                         intent.setClass(OperateActivity.this, Article.class);         startActivity(intent);                            }                        });                    } else {                    }                } catch (JSONException e) {                    e.printStackTrace();                }break;default:break;        }    }};private class OperateThread implements Runnable {@Overridepublic void run() {path = path_url + 1 + "/aa/" + count;responseMsg = JsonUtil.loginServer(path);        Message msg = handler.obtainMessage();try {jsonObject = new JSONObject(responseMsg);        } catch (JSONException e) {            e.printStackTrace();        }        msg.what = 0;handler.sendMessage(msg);    }}

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