我在代码中使用了asynctask。但是它显示了我在logcat中给出的错误。我创建了一个api 18.in的google api模拟器，它不能正常工作。但是在api8中工作。它是否适用于任何版本的真实设备？
btnLogin.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
new LoginTask_1().execute();
}
});
的AsyncTask
class LoginTask_1 extends AsyncTask<String, String, String> {
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(RegisterActivity.this);
pDialog.setMessage("loging in...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
/**
* Deleting product
* */
protected String doInBackground(String... args) {
runOnUiThread(new Runnable() {
public void run() {
String code = inputcode.getText().toString();
UserFunctions userFunction = new UserFunctions();
Log.d("Button", "Login");
JSONObject json = userFunction.loginUser1(id,code);
// check for login response
try {
if (json.getString(KEY_SUCCESS) != null) {
loginErrorMsg1.setText("");
String res = json.getString(KEY_SUCCESS);
if(Integer.parseInt(res) == 1){
DatabaseHandler1 db = new DatabaseHandler1(getApplicationContext());
db.addUser(adduser1, adduser2,id, adduser3,adduser4);
// Launch Dashboard Screen
Intent dashboard = new Intent(getApplicationContext(), MainActivity.class);
dashboard.putExtra("name", id);
dashboard.putExtra("email", adduser4);
//dashboard.putExtra(EXTRA_MESSAGE, id);
// Close all views before launching Dashboard
dashboard.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(dashboard);
// Close Login Screen
finish();
}
/*else if(Integer.parseInt(res) == 2){
loginErrorMsg.setText("Already logged in");
}*/
else{
// Error in login
loginErrorMsg1.setText("Invalid Code");
}
}
} catch (JSONException e) {
e.printStackTrace();
}
}
});
return null;
}
/**
* After completing background task Dismiss the progress dialog
* **/
protected void onPostExecute(String file_url) {
// dismiss the dialog once product deleted
pDialog.dismiss();
}
}
logcat的
03-21 06:47:54.403: E/AndroidRuntime(3265): FATAL EXCEPTION: main
03-21 06:47:54.403: E/AndroidRuntime(3265): android.os.NetworkOnMainThreadException
03-21 06:47:54.403: E/AndroidRuntime(3265): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1133)
03-21 06:47:54.403: E/AndroidRuntime(3265): at java.net.InetAddress.lookupHostByName(InetAddress.java:385)
03-21 06:47:54.403: E/AndroidRuntime(3265): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:236)
03-21 06:47:54.403: E/AndroidRuntime(3265): at java.net.InetAddress.getAllByName(InetAddress.java:214)
03-21 06:47:54.403: E/AndroidRuntime(3265): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
03-21 06:47:54.403: E/AndroidRuntime(3265): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
03-21 06:47:54.403: E/AndroidRuntime(3265): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
03-21 06:47:54.403: E/AndroidRuntime(3265): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
03-21 06:47:54.403: E/AndroidRuntime(3265): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
03-21 06:47:54.403: E/AndroidRuntime(3265): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
03-21 06:47:54.403: E/AndroidRuntime(3265): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
03-21 06:47:54.403: E/AndroidRuntime(3265): at com.androidhive.pushnotifications.JSONParser.getJSONFromUrl(JSONParser.java:47)
03-21 06:47:54.403: E/AndroidRuntime(3265): at com.androidhive.pushnotifications.UserFunctions.loginUser(UserFunctions.java:46)
03-21 06:47:54.403: E/AndroidRuntime(3265): at com.androidhive.pushnotifications.LoginActivity$LoginTask$1.run(LoginActivity.java:125)
03-21 06:47:54.403: E/AndroidRuntime(3265): at android.os.Handler.handleCallback(Handler.java:730)
03-21 06:47:54.403: E/AndroidRuntime(3265): at android.os.Handler.dispatchMessage(Handler.java:92)
03-21 06:47:54.403: E/AndroidRuntime(3265): at android.os.Looper.loop(Looper.java:137)
03-21 06:47:54.403: E/AndroidRuntime(3265): at android.app.ActivityThread.main(ActivityThread.java:5103)
03-21 06:47:54.403: E/AndroidRuntime(3265): at java.lang.reflect.Method.invokeNative(Native Method)
03-21 06:47:54.403: E/AndroidRuntime(3265): at java.lang.reflect.Method.invoke(Method.java:525)
03-21 06:47:54.403: E/AndroidRuntime(3265): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
03-21 06:47:54.403: E/AndroidRuntime(3265): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
03-21 06:47:54.403: E/AndroidRuntime(3265): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：1)
删除runOnUiThread
runOnUiThread(new Runnable() {
public void run() {
在后台线程上调用您的doInbackground。您不需要runOnUiThread来执行网络操作。
并在doInbackground中的onPostExecute和startActivity中返回结果。
编辑：
正如onPostExecute中doInbackground而不是 loginErrorMsg1.setText("Invalid Code");
中的繁荣k upadate ui所暗示的那样
doInbackground此外，您可以从Activity中的EditText获取文本，并将字符串传递给 btnLogin.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
String code = inputcode.getText().toString();
new LoginTask_1().execute(code);
}
});
protected String doInBackground(String... args) {
String value = args[0];
然后
{{1}}