奋斗 - Part 4

@Override
protected Dialog onCreateDialog(int id) {
if(1 == id)
{
ProgressDialog dialog = new ProgressDialog(GTranslator.this);
dialog.setTitle(“正在查询”);
dialog.setMessage(“请稍候……”);
return dialog;
}
return null;
}

但是查询是个阻塞的过程
我们必须得在另外一个线程里去做这个事情
比较简单的方法就是继承AsyncTask
网上有一篇转载比较多的关于AsyncTask的文章(Android线程模型（Painless Threading）)
官方的说明在这里 http://developer.android.com/reference/android/os/AsyncTask.html
大概说一下 android 的ui线程不是线程安全的
我们不能在其他的线程里直接做关于ui的操作
这里有个简单的办法就是继承AsyncTask
然后实现它的doInBackground方法
在类的onPreExecute(),publishProgress(Progress…),onPostExecute(Result)方法里
做ui的操作
如果在doInBackground里操作ui
可能会弹出异常提示
“Only the original thread that created a view hierarchy can touch its views”
不是每次都弹…为什么了?

下面贴一下线程的代码

	private class ProcessDialogThread extends AsyncTask<String, Void, String> {
		// @Override
		protected String doInBackground(String... str) {
 
			String toTranslateTextString = toTranslateEditText.getText()
					.toString();
			String tempString = toTranslateTextString.replace(" ", "%20");
			fromString = mCountries[fromSpinner.getSelectedItemPosition()];
			toString = mCountries[toSpinner.getSelectedItemPosition()];
			String queryString = tempString + "&langpair=" + fromString + "%7C"
					+ toString;
 
			return getRawData(queryString);
		}
 
		protected void onPreExecute() {
			showDialog(1);
			translatedTextView.setText("Connecting...");
		}
 
		protected void onPostExecute(String rawData) {
			dismissDialog(1);
			if (null != rawData) {
				String parsedDataString = getData(rawData);
				if (null == parsedDataString || "" == parsedDataString) {
					try {
						translatedTextView.setText("Not found");
					} catch (Exception e) {
						e.printStackTrace();
					}
				} else {
					translatedTextView.setText(parsedDataString);
					dbAdapter.insertItem(toTranslateEditText.getText()
							.toString(), parsedDataString);
 
					/*
					 * FileAccess.writeFile(this,
					 * toTranslateEditText.getText().toString() + ":" +
					 * parsedDataString);
					 */
				}
			} else {
				translatedTextView.setText("Translate failed!");
			}
		}
 
		public String getRawData(String string) {
			String dataString = null;
			// String queryString = "hello%20world&langpair=en%7Czh-CN";
			String queryString = string;
			try {
				URL url;
				if (bAtOffice) {
					url = new URL("http://10.85.40.153:8000/a.xml");
				} else {
					url = new URL(
							"http://ajax.googleapis.com/ajax/services/language/translate?v=1.0&q="
									+ queryString);
				}
 
				URLConnection conn = url.openConnection();
				conn.connect();
				BufferedReader reader = new BufferedReader(
						new InputStreamReader(conn.getInputStream()));
 
				byte buffer[] = new byte[1024];
 
				// bis.r
				String readerString;
				while ((readerString = reader.readLine()) != null) {
					dataString += readerString;
				}
 
				reader.close();
				// is.close();
 
			} catch (IOException e) {
				System.out.print("Net work error");
			}
			return dataString;
		}
	}