我在我的应用程序中同时使用SwipeRefreshLayout和AsyncTask。我知道，如果我要两次使用AsyncTask，则必须创建一个新实例来使所有程序运行。但是，当我按以下步骤进行操作时，该过程将卡住，并且不会刷新数据。滑动按钮会永远持续下去。
这里是Function.java：
public interface AsyncResponse {
void processFinish(String output1, String output2, String output3, String output4, String output5, String output6,
String output7, String output8, String output9, String output10, String output11, String output12,
String output13, String output14, String output15, String output16, String output17, String output18,
String output19, String output20, String output21, String output22, String output23, String output24);
}
public static class placeIdTask extends AsyncTask<String, Void, JSONObject> {
public AsyncResponse delegate = null; //Call back interface
public placeIdTask(AsyncResponse asyncResponse) {
delegate = asyncResponse; //Assigning call back interface through constructor
}
@Override
protected JSONObject doInBackground(String... params) {
JSONObject jsonWeather = null;
try {
jsonWeather = getWeatherJSON();
} catch (Exception e) {
Log.d("Error", "Cannot process JSON results", e);
}
return jsonWeather;
}
@Override
protected void onPostExecute(JSONObject json) {
try {
if (json != null) {
...... // more code
delegate.processFinish(description, temperature, humidity, windspeed, updatedOn, iconText,
first_hour_icon, first_hour_text, first_hour_temperature,
third_hour_icon, third_hour_text, third_hour_temperature,
ninth_hour_icon, ninth_hour_text, ninth_hour_temperature,
first_day_icon, first_day_text, first_day_temperature,
second_day_icon, second_day_text, second_day_temperature,
third_day_icon, third_day_text, third_day_temperature);
}
} catch (JSONException e) {
Log.e("Json Procession failed", e.toString());
}
}
}
public static JSONObject getWeatherJSON() { ... } // to retrieve data from the Internet
这里是MainActivity.java：
... get everything imported
public class MainActivity extends AppCompatActivity {
... Variables declared
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
getSupportActionBar().hide();
setContentView(R.layout.activity_main);
weatherFont = Typeface.createFromAsset(getApplicationContext().getAssets(), "fonts/weathericons-regular-webfont.ttf");
...use findviewbyid to get things working
final Function.placeIdTask asyncTask =new Function.placeIdTask(new Function.AsyncResponse() {
public void processFinish(String weather_description, String weather_temperature, String weather_humidity, String weather_windspeed, String weather_updatedOn, String weather_iconText,
String weather_firstHourIcon, String weather_firstHourText, String weather_firstHourTemperature,
String weather_thirdHourIcon, String weather_thirdHourText, String weather_thirdHourTemperature,
String weather_ninthHourIcon, String weather_ninthHourText, String weather_ninthHourTemperature,
String weather_firstDayIcon, String weather_firstDayText, String weather_firstDayTemperature,
String weather_secondDayIcon, String weather_secondDayText, String weather_secondDayTemperature,
String weather_thirdDayIcon, String weather_thirdDayText, String weather_thirdDayTemperature) {
updatedField.setText(weather_updatedOn);
detailsField.setText(weather_description);
currentTemperatureField.setText(weather_temperature);
humidity_field.setText("Humidity: " + weather_humidity);
windspeed_field.setText("Wind Speed: " + weather_windspeed);
firstHourText.setText(weather_firstHourText);
thirdHourText.setText(weather_thirdHourText);
ninthHourText.setText(weather_ninthHourText);
firstHourTemperature.setText(weather_firstHourTemperature);
thirdHourTemperature.setText(weather_thirdHourTemperature);
ninthHourTemperature.setText(weather_ninthHourTemperature);
firstDayText.setText(weather_firstDayText);
secondDayText.setText(weather_secondDayText);
thirdDayText.setText(weather_thirdDayText);
firstDayTemperature.setText(weather_firstDayTemperature);
secondDayTemperature.setText(weather_secondDayTemperature);
thirdDayTemperature.setText(weather_thirdDayTemperature);
weatherIcon.setText(Html.fromHtml(weather_iconText));
firstHourIcon.setText(Html.fromHtml(weather_firstHourIcon));
thirdHourIcon.setText(Html.fromHtml(weather_thirdHourIcon));
ninthHourIcon.setText(Html.fromHtml(weather_ninthHourIcon));
firstDayIcon.setText(Html.fromHtml(weather_firstDayIcon));
secondDayIcon.setText(Html.fromHtml(weather_secondDayIcon));
thirdDayIcon.setText(Html.fromHtml(weather_thirdDayIcon));
}
});
asyncTask.execute();
refreshLayout = (SwipeRefreshLayout)findViewById(R.id.refresh_layout);
scrollView = (NestedScrollView)findViewById(R.id.nested_scroll_view);
refreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
@Override
public void onRefresh() {
Function.placeIdTask asyncTask2 =new Function.placeIdTask(new Function.AsyncResponse() {
public void processFinish(String weather_description, String weather_temperature, String weather_humidity, String weather_windspeed, String weather_updatedOn, String weather_iconText,
String weather_firstHourIcon, String weather_firstHourText, String weather_firstHourTemperature,
String weather_thirdHourIcon, String weather_thirdHourText, String weather_thirdHourTemperature,
String weather_ninthHourIcon, String weather_ninthHourText, String weather_ninthHourTemperature,
String weather_firstDayIcon, String weather_firstDayText, String weather_firstDayTemperature,
String weather_secondDayIcon, String weather_secondDayText, String weather_secondDayTemperature,
String weather_thirdDayIcon, String weather_thirdDayText, String weather_thirdDayTemperature) {
updatedField.setText(weather_updatedOn);
detailsField.setText(weather_description);
currentTemperatureField.setText(weather_temperature);
humidity_field.setText("Humidity: " + weather_humidity);
windspeed_field.setText("Wind Speed: " + weather_windspeed);
firstHourText.setText(weather_firstHourText);
thirdHourText.setText(weather_thirdHourText);
ninthHourText.setText(weather_ninthHourText);
firstHourTemperature.setText(weather_firstHourTemperature);
thirdHourTemperature.setText(weather_thirdHourTemperature);
ninthHourTemperature.setText(weather_ninthHourTemperature);
firstDayText.setText(weather_firstDayText);
secondDayText.setText(weather_secondDayText);
thirdDayText.setText(weather_thirdDayText);
firstDayTemperature.setText(weather_firstDayTemperature);
secondDayTemperature.setText(weather_secondDayTemperature);
thirdDayTemperature.setText(weather_thirdDayTemperature);
weatherIcon.setText(Html.fromHtml(weather_iconText));
firstHourIcon.setText(Html.fromHtml(weather_firstHourIcon));
thirdHourIcon.setText(Html.fromHtml(weather_thirdHourIcon));
ninthHourIcon.setText(Html.fromHtml(weather_ninthHourIcon));
firstDayIcon.setText(Html.fromHtml(weather_firstDayIcon));
secondDayIcon.setText(Html.fromHtml(weather_secondDayIcon));
thirdDayIcon.setText(Html.fromHtml(weather_thirdDayIcon));
}
});
asyncTask2.execute();
refreshLayout.setRefreshing(true);
}
});
}
}
我是SwipeRefreshLayout和Java和Android的新手，很难理解文档。谁能帮我吗？预先感谢。
答案 0 :(得分：1)
在processFinish（..）内部执行refreshLayout.setRefreshing（false）
此外，您也可以在一个函数本身中创建asynctask，以免编写两次将asnyctask实例化的代码。
也可以使用日志或调试器调试代码，并告诉我。