我尝试在设备上运行我的Android应用程序，我的登录崩溃了。 logcat显示此错误
09-12 21:32:12.289: E/AudioHardwareALSA(149): RE-OPEN AFTER STANDBY:: took 115 msecs
09-12 21:32:12.319: E/AndroidRuntime(4760): FATAL EXCEPTION: main
09-12 21:32:12.319: E/AndroidRuntime(4760): android.os.NetworkOnMainThreadException
09-12 21:32:12.319: E/AndroidRuntime(4760): at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1099)
09-12 21:32:12.319: E/AndroidRuntime(4760): at java.net.InetAddress.lookupHostByName(InetAddress.java:391)
09-12 21:32:12.319: E/AndroidRuntime(4760): at java.net.InetAddress.getAllByNameImpl(InetAddress.java:242)
09-12 21:32:12.319: E/AndroidRuntime(4760): at java.net.InetAddress.getAllByName(InetAddress.java:220)
09-12 21:32:12.319: E/AndroidRuntime(4760): at org.apache.http.impl.conn.DefaultClientConnectionOperator.openConnection(DefaultClientConnectionOperator.java:137)
09-12 21:32:12.319: E/AndroidRuntime(4760): at org.apache.http.impl.conn.AbstractPoolEntry.open(AbstractPoolEntry.java:164)
09-12 21:32:12.319: E/AndroidRuntime(4760): at org.apache.http.impl.conn.AbstractPooledConnAdapter.open(AbstractPooledConnAdapter.java:119)
09-12 21:32:12.319: E/AndroidRuntime(4760): at org.apache.http.impl.client.DefaultRequestDirector.execute(DefaultRequestDirector.java:360)
09-12 21:32:12.319: E/AndroidRuntime(4760): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:555)
09-12 21:32:12.319: E/AndroidRuntime(4760): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:487)
09-12 21:32:12.319: E/AndroidRuntime(4760): at org.apache.http.impl.client.AbstractHttpClient.execute(AbstractHttpClient.java:465)
09-12 21:32:12.319: E/AndroidRuntime(4760): at com.stts.sparetimetradingsystem.library.JSONParser.getJSONFromUrl(JSONParser.java:44)
09-12 21:32:12.319: E/AndroidRuntime(4760): at com.stts.sparetimetradingsystem.library.UserFunctions.loginUser(UserFunctions.java:40)
09-12 21:32:12.319: E/AndroidRuntime(4760): at com.stts.sparetimetradingsystem.LoginActivity$Login$1.run(LoginActivity.java:125)
09-12 21:32:12.319: E/AndroidRuntime(4760): at android.os.Handler.handleCallback(Handler.java:605)
09-12 21:32:12.319: E/AndroidRuntime(4760): at android.os.Handler.dispatchMessage(Handler.java:92)
09-12 21:32:12.319: E/AndroidRuntime(4760): at android.os.Looper.loop(Looper.java:137)
09-12 21:32:12.319: E/AndroidRuntime(4760): at android.app.ActivityThread.main(ActivityThread.java:4424)
09-12 21:32:12.319: E/AndroidRuntime(4760): at java.lang.reflect.Method.invokeNative(Native Method)
09-12 21:32:12.319: E/AndroidRuntime(4760): at java.lang.reflect.Method.invoke(Method.java:511)
09-12 21:32:12.319: E/AndroidRuntime(4760): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:787)
09-12 21:32:12.319: E/AndroidRuntime(4760): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:554)
09-12 21:32:12.319: E/AndroidRuntime(4760): at dalvik.system.NativeStart.main(Native Method)
我哪里做错了？
修改
这是我的登录代码，它位于异步任务中，我可以知道我的异步任务是否正确编码：
// Background ASYNC Task to login by making HTTP Request
class Login extends AsyncTask<String, String, String> {
// Before starting background thread Show Progress Dialog
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(LoginActivity.this);
pDialog.setMessage("Authenticating...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
// Checking login in background
protected String doInBackground(String... params) {
runOnUiThread(new Runnable() {
public void run() {
String email = inputEmail.getText().toString();
String password = inputPassword.getText().toString();
UserFunctions userFunction = new UserFunctions();
JSONObject json = userFunction.loginUser(email, password);
// check for login response
try {
if (json.getString(KEY_SUCCESS) != null) {
loginErrorMsg.setText("");
String res = json.getString(KEY_SUCCESS);
if (Integer.parseInt(res) == 1) {
validUser = true;
// user successfully logged in
// Store user details in SQLite Database
DatabaseHandler db = new DatabaseHandler(
getApplicationContext());
JSONObject json_user = json
.getJSONObject("user");
// Clear all previous data in database
userFunction
.logoutUser(getApplicationContext());
db.addUser(json_user.getString(KEY_NAME),
json_user.getString(KEY_EMAIL),
json.getString(KEY_UID),
json_user.getString(KEY_CREATED_AT));
} else {
// Error in login
loginErrorMsg
.setText("Incorrect username/password");
}
}
} 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 done
pDialog.dismiss();
if (validUser == true) {
loginErrorMsg.setText("");
// Launch HomePage Screen
Intent homepage = new Intent(getApplicationContext(),
HomepageActivity.class);
// Close all views before launching HomePage
homepage.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(homepage);
// Close Login Screen
finish();
}
}
}
答案 0 :(得分：2)
Android不允许从android 3.0（Honeycomb）开始在主线程上进行网络调用。 因此，您必须使用Asynctask进行网络呼叫。
要摆脱这种情况，您需要使用AsynTask进行网络调用。
答案 1 :(得分：2)
您正在使用AsyncTask但在doInBackground中，您实际上是通过以下方式执行网络代码：
runOnUiThread(new Runnable() { }
这就是为什么你最终得到这个例外的原因，你需要在没有它的情况下执行你的网络代码。我想你这样做是为了引用应用程序上下文，但只是通过AsyncTask构造函数提供它是相当简单的。