我目前正在处理一个小组项目，我们正在尝试从 asynctask 中的 JSON 查询中获取字符串值，以便通过 intents 将它们发送到第二个 Activity 。我们遇到的麻烦是当字符串从 asynctask 中取出时，它变为 null。如何解决？
public class connectTask extends AsyncTask<String,String,TCPClient> {
String FilmId, Name, Certificate, Duration, Director, Description, ReleaseDate, Cast;
@Override
protected TCPClient doInBackground(String... message) {
//we create a TCPClient object and
mTcpClient = new TCPClient(new TCPClient.OnMessageReceived() {
@Override
//here the messageReceived method is implemented
public void messageReceived(String message) {
//this method calls the onProgressUpdate
Log.e("TCP Client", message);
try
{
JSONObject json = new JSONObject(message);
FilmId = (String) json.get("FilmId");
Name = (String) json.get("Name");
Certificate = (String) json.get("Certificate");
Duration =(String) json.get("Duration");
Director = (String) json.get("Director");
Description = (String) json.get("Description");
ReleaseDate = (String) json.get("ReleaseDate");
Cast = (String) json.get("Cast");
Log.e("FilmId: ", FilmId);
Log.e("Name: ", Name);
Log.e("Cert: ", Certificate);
Log.e("Duration: ", Duration);
Log.e("Director: ", Director);
Log.e("Description: ", Description);
Log.e("ReleaseDate: ", ReleaseDate);
Log.e("Cast: ", Cast);
}
catch (JSONException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
mTcpClient.run("GTF 02");
System.out.println(JSON[1]);
return null;
}
protected void onPostExecute()
{
JSON[0] = FilmId;
JSON[1] = Name;
}
}
public void mLoadFilmInfo(View view)
{
//FilmID = "GTF "+ ButtonName;
new connectTask().execute();
Intent FilmInfo = new Intent(this, FilmInfo.class);
FilmInfo.putExtra("NamePass", JSON[1]);
startActivity(FilmInfo);
}
这是异步任务和传递给第二个 Activity 的代码。
非常感谢任何帮助。
最佳答案
AsyncTask 与您的代码并行运行。它不会在执行完成后立即完成。您在 execute() 下的所有代码都需要在您的 onPostExecute 中。
关于java - 如何从异步任务中的 JSON 查询返回多个字符串？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/22306511/