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本文实例讲述了Android实现TextView显示HTML加图片的方法。分享给大家供大家参考,具体如下:
TextView显示网络图片,我用android2.3的系统,可以显示图片出来,并且如果图片比较大,应用会卡的现象,肯定是因为使用主线程去获取网络图片造成的,但如果我用android4.0以上的系统运行,则不能显示图片,只显示小方框。
究其原因,是在4.0的系统上执行的时候报错了,异常是:Android.os.NetworkOnMainThreadException 经过查文档,原来是4.0系统不允许主线程(UI线程)访问网络,因此导致了其异常。说白了就是在主线程上访问网络,会造成主线程挂起,系统不允许使用了。
此处有作部分修改,代码独立。图片实现异步加载。解决上述问题
用法,调用代码activity
//TextView 控件textViewContent = (TextView) getActivity().findViewById(R.id.textview_prodcut_detail_more_zp_content);//HTML文本zp_content = "测试图片信息:<br><img src="http://b2c.zeeeda.com/upload/2013/05/10/136814766742544.jpg" />";//默认图片,无图片或没加载完显示此图片Drawable defaultDrawable = MainActivity.ma.getResources().getDrawable(R.drawable.stub);//调用Spanned sp = Html.fromHtml(zp_content, new HtmlImageGetter(textViewContent, "/esun_msg", defaultDrawable), null);textViewContent.setText(sp);
HtmlImageGetter类:
import java.io.InputStream;import android.graphics.Canvas;import android.graphics.drawable.BitmapDrawable;import android.graphics.drawable.Drawable;import android.os.AsyncTask;import android.os.Environment;import android.text.Html.ImageGetter;import android.util.Log;import android.widget.TextView;public class HtmlImageGetter implements ImageGetter{private TextView _htmlText;private String _imgPath;private Drawable _defaultDrawable;private String TAG = "HtmlImageGetter";public HtmlImageGetter(TextView htmlText, String imgPath, Drawable defaultDrawable){_htmlText = htmlText;_imgPath = imgPath;_defaultDrawable = defaultDrawable;}@Overridepublic Drawable getDrawable(String imgUrl) {String imgKey = String.valueOf(imgUrl.hashCode());String path = Environment.getExternalStorageDirectory() + _imgPath;FileUtil.createPath(path);String[] ss = imgUrl.split("\.");String imgX = ss[ss.length-1];imgKey = path+"/" + imgKey+"."+imgX;if(FileUtil.exists(imgKey)){Drawable drawable = FileUtil.getImageDrawable(imgKey);if(drawable != null){drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());return drawable;}else{Log.v(TAG,"load img:"+imgKey+":null");}}URLDrawable urlDrawable = new URLDrawable(_defaultDrawable);new AsyncThread(urlDrawable).execute(imgKey, imgUrl);return urlDrawable;}private class AsyncThread extends AsyncTask<String, Integer, Drawable> {private String imgKey;private URLDrawable _drawable;public AsyncThread(URLDrawable drawable){_drawable = drawable;}@Overrideprotected Drawable doInBackground(String... strings) {imgKey = strings[0];InputStream inps = NetWork.getInputStream(strings[1]);if(inps == null) return _drawable;FileUtil.saveFile(imgKey, inps);Drawable drawable = Drawable.createFromPath(imgKey);return drawable;}public void onProgressUpdate(Integer... value) {}@Overrideprotected void onPostExecute(Drawable result) {_drawable.setDrawable(result);_htmlText.setText(_htmlText.getText());}}public class URLDrawable extends BitmapDrawable {private Drawable drawable;public URLDrawable(Drawable defaultDraw){setDrawable(defaultDraw);}private void setDrawable(Drawable ndrawable){drawable = ndrawable;drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());}@Overridepublic void draw(Canvas canvas) {drawable.draw(canvas);}}}
NetWork 类:
import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.io.PrintWriter;import java.net.HttpURLConnection;import java.net.MalformedURLException;import java.net.URL;import java.util.HashMap;import java.util.Iterator;import java.util.Map;import java.util.zip.GZIPInputStream;import java.util.zip.InflaterInputStream;import org.apache.http.HttpEntity;import org.apache.http.HttpResponse;import org.apache.http.client.HttpClient;import org.apache.http.client.methods.HttpGet;import org.apache.http.entity.BufferedHttpEntity;import org.apache.http.impl.client.DefaultHttpClient;import android.graphics.Bitmap;import android.graphics.BitmapFactory;import android.util.Log;public class NetWork {private static String TAG = "NetWork";public static String getHttpData(String baseUrl){return getHttpData(baseUrl, "GET", "", null);}public static String postHttpData(String baseUrl, String reqData){return getHttpData(baseUrl, "POST", reqData, null);}public static String postHttpData(String baseUrl, String reqData, HashMap<String, String> propertys){return getHttpData(baseUrl, "POST", reqData, propertys);}/** * 获取赛事信息 * @return */public static String getHttpData(String baseUrl, String method, String reqData, HashMap<String, String> propertys){String data = "", str;PrintWriter outWrite = null;InputStream inpStream = null;BufferedReader reader = null;HttpURLConnection urlConn = null;try{URL url = new URL(baseUrl);urlConn = (HttpURLConnection)url.openConnection();//启用gzip压缩urlConn.addRequestProperty("Accept-Encoding", "gzip, deflate");urlConn.setRequestMethod(method);urlConn.setDoOutput(true);urlConn.setConnectTimeout(3000);if(propertys != null && !propertys.isEmpty()){Iterator<Map.Entry<String, String>> props = propertys.entrySet().iterator();Map.Entry<String, String> entry;while (props.hasNext()){entry = props.next();urlConn.setRequestProperty(entry.getKey(), entry.getValue());}}outWrite = new PrintWriter(urlConn.getOutputStream());outWrite.print(reqData);outWrite.flush();urlConn.connect();//获取数据流inpStream = urlConn.getInputStream();String encode = urlConn.getHeaderField("Content-Encoding");//如果通过gzipif(encode !=null && encode.indexOf("gzip") != -1){Log.v(TAG, "get data :" + encode);inpStream = new GZIPInputStream(inpStream);}else if(encode != null && encode.indexOf("deflate") != -1){inpStream = new InflaterInputStream(inpStream);}reader = new BufferedReader(new InputStreamReader(inpStream));while((str = reader.readLine()) != null){data += str;}}catch (MalformedURLException ex){ex.printStackTrace();}catch (IOException ex){ex.printStackTrace();}finally{if(reader !=null && urlConn!=null){try {outWrite.close();inpStream.close();reader.close();urlConn.disconnect();} catch (IOException ex) {ex.printStackTrace();}}}Log.d(TAG, "[Http data]["+baseUrl+"]:" + data);return data;}/** * 获取Image信息 * @return */public static Bitmap getBitmapData(String imgUrl){Bitmap bmp = null;Log.d(TAG, "get imgage:"+imgUrl);InputStream inpStream = null;try{HttpGet http = new HttpGet(imgUrl);HttpClient client = new DefaultHttpClient();HttpResponse response = (HttpResponse)client.execute(http);HttpEntity httpEntity = response.getEntity();BufferedHttpEntity bufferedHttpEntity = new BufferedHttpEntity(httpEntity);//获取数据流inpStream = bufferedHttpEntity.getContent();bmp = BitmapFactory.decodeStream(inpStream);}catch (Exception ex){ex.printStackTrace();}finally{if(inpStream !=null){try {inpStream.close();} catch (IOException ex) {ex.printStackTrace();}}}return bmp;}/** * 获取url的InputStream * @param urlStr * @return */public static InputStream getInputStream(String urlStr){Log.d(TAG, "get http input:"+urlStr);InputStream inpStream = null;try{HttpGet http = new HttpGet(urlStr);HttpClient client = new DefaultHttpClient();HttpResponse response = (HttpResponse)client.execute(http);HttpEntity httpEntity = response.getEntity();BufferedHttpEntity bufferedHttpEntity = new BufferedHttpEntity(httpEntity);//获取数据流inpStream = bufferedHttpEntity.getContent();}catch (Exception ex){ex.printStackTrace();}finally{if(inpStream !=null){try {inpStream.close();} catch (IOException ex) {ex.printStackTrace();}}}return inpStream;}}
FileUtil类:
import java.io.File;import java.io.FileInputStream;import java.io.FileOutputStream;import java.io.IOException;import java.io.InputStream;import java.io.OutputStream;import android.graphics.drawable.BitmapDrawable;import android.graphics.drawable.Drawable;import android.os.Environment;import android.util.Log;public class FileUtil {private static int FILE_SIZE = 4*1024;private static String TAG = "FileUtil";public static boolean hasSdcard(){String status = Environment.getExternalStorageState();if(status.equals(Environment.MEDIA_MOUNTED)){return true;}return false;}public static boolean createPath(String path){File f = new File(path);if(!f.exists()){Boolean o = f.mkdirs();Log.i(TAG, "create dir:"+path+":"+o.toString());return o;}return true;}public static boolean exists(String file){return new File(file).exists();}public static File saveFile(String file, InputStream inputStream){File f = null;OutputStream outSm = null;try{f = new File(file);String path = f.getParent();if(!createPath(path)){Log.e(TAG, "can"t create dir:"+path);return null;}if(!f.exists()){f.createNewFile();}outSm = new FileOutputStream(f);byte[] buffer = new byte[FILE_SIZE];while((inputStream.read(buffer)) != -1){outSm.write(buffer);}outSm.flush();}catch (IOException ex) {ex.printStackTrace();return null;}finally{try{if(outSm != null) outSm.close();}catch (IOException ex) {ex.printStackTrace();}}Log.v(TAG,"[FileUtil]save file:"+file+":"+Boolean.toString(f.exists()));return f;}public static Drawable getImageDrawable(String file){if(!exists(file)) return null;try{InputStream inp = new FileInputStream(new File(file));return BitmapDrawable.createFromStream(inp, "img");}catch (Exception ex){ex.printStackTrace();}return null;}}
更多关于Android相关内容感兴趣的读者可查看本站专题:《Android编程之activity操作技巧总结》、《Android资源操作技巧汇总》、《Android文件操作技巧汇总》、《Android操作SQLite数据库技巧总结》、《Android操作json格式数据技巧总结》、《Android数据库操作技巧总结》、《Android编程开发之SD卡操作方法汇总》、《Android开发入门与进阶教程》、《Android视图View技巧总结》及《Android控件用法总结》
希望本文所述对大家Android程序设计有所帮助。