我扩展了 Application 类,以便在 android 中创建类似单例的对象。
在这个对象中,我的所有 HTTP 都与我的服务器一起工作,所有其他 Activity 都可以访问它并调用 GET、POST 等方法。
代码:
public class HttpManagerInstance extends Application {
private HttpClient httpClient;
private HttpGet get;
@Override
public void onCreate() {
httpClient = new DefaultHttpClient();
get = new HttpGet("http://10.100.102.9:8000/users/");
super.onCreate();
}
public Void getUsers() throws Exception {
new executeRequest().execute(get);
return null;
}
private class executeRequest extends AsyncTask<HttpRequest, Void, Integer> {
@Override
protected Integer doInBackground(HttpRequest... params) {
// TODO Auto-generated method stub
HttpRequest request = params[0];
HttpResponse response;
String result="";
try {
response = httpClient.execute((HttpUriRequest) request);
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return responseCode;
}
@Override
protected void onPostExecute(Integer result) {
// TODO Auto-generated method stub
switch (result) {
case HttpStatus.SC_OK:
// request was fine
// Here I want to updated the GUI of the activity that called this method.
break;
}
}
}
}
这是我从 Activity 调用方法的方式:
HttpManagerInstance sampleApp = (HttpManagerInstance)getApplicationContext();
sampleApp.getUsers();
同样 - 我想访问调用该方法以放置 REQUEST ACCEPTED 消息的 Activity 的 UI。
也许传递上下文?有什么想法吗?
最佳答案
我会创建一个监听器:
public class HttpManagerInstance extends Application {
private HttpClient httpClient;
private HttpGet get;
public interface ResponseListener{
public void onSuccess(Object data);
}
@Override
public void onCreate() {
httpClient = new DefaultHttpClient();
get = new HttpGet("http://10.100.102.9:8000/users/");
super.onCreate();
}
public Void getUsers(ResponseListener listener) throws Exception {
new executeRequest(listener).execute(get);
return null;
}
private class executeRequest extends AsyncTask<HttpRequest, Void, Integer> {
private ResponseListener mListener;
public executeRequest(ResponseListener listener){
this.mListener = listener;
}
@Override
protected Integer doInBackground(HttpRequest... params) {
// TODO Auto-generated method stub
HttpRequest request = params[0];
HttpResponse response;
String result="";
try {
response = httpClient.execute((HttpUriRequest) request);
} catch (ClientProtocolException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return responseCode;
}
@Override
protected void onPostExecute(Integer result) {
// TODO Auto-generated method stub
switch (result) {
case HttpStatus.SC_OK:
// request was fine
// Here I want to updated the GUI of the activity that called this method.
if(this.mListener != null) mListener.onSuccess(whatEverDataYouWant);
break;
}
}
}
}
然后,在您的 Activity 中:
HttpManagerInstance sampleApp = (HttpManagerInstance)getApplicationContext();
sampleApp.getUsers(new ResponseListener(){
public void onSuccess(Object data){
//update your ui!
}
});
关于android - 从应用程序类更改 Activity UI,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/30441524/