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我一直在創建一個應用程序來記錄和註冊用戶，在使用一個asynctask，但認爲我做到了這一點。請參閱下面的錯誤消息和代碼Android操作時崩潰
04-16 11:27:17.160: D/AndroidRuntime(31658): Shutting down VM
04-16 11:27:17.160: W/dalvikvm(31658): threadid=1: thread exiting with uncaught exception (group=0x41c4c700)
04-16 11:27:17.175: E/AndroidRuntime(31658): FATAL EXCEPTION: main
04-16 11:27:17.175: E/AndroidRuntime(31658): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.applicationnfclogin/com.applicationnfclogin.DashboardActivity}: android.view.InflateException: Binary XML file line #92: Error inflating class progressbar
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2295)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2349)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.app.ActivityThread.access$700(ActivityThread.java:159)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.os.Handler.dispatchMessage(Handler.java:99)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.os.Looper.loop(Looper.java:176)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.app.ActivityThread.main(ActivityThread.java:5419)
04-16 11:27:17.175: E/AndroidRuntime(31658): at java.lang.reflect.Method.invokeNative(Native Method)
04-16 11:27:17.175: E/AndroidRuntime(31658): at java.lang.reflect.Method.invoke(Method.java:525)
04-16 11:27:17.175: E/AndroidRuntime(31658): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1046)
04-16 11:27:17.175: E/AndroidRuntime(31658): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:862)
04-16 11:27:17.175: E/AndroidRuntime(31658): at dalvik.system.NativeStart.main(Native Method)
04-16 11:27:17.175: E/AndroidRuntime(31658): Caused by: android.view.InflateException: Binary XML file line #92: Error inflating class progressbar
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:713)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.view.LayoutInflater.rInflate(LayoutInflater.java:761)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.view.LayoutInflater.inflate(LayoutInflater.java:498)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.view.LayoutInflater.inflate(LayoutInflater.java:398)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.view.LayoutInflater.inflate(LayoutInflater.java:354)
04-16 11:27:17.175: E/AndroidRuntime(31658): at com.android.internal.policy.impl.PhoneWindow.setContentView(PhoneWindow.java:361)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.app.Activity.setContentView(Activity.java:1956)
04-16 11:27:17.175: E/AndroidRuntime(31658): at com.applicationnfclogin.DashboardActivity.onCreate(DashboardActivity.java:23)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.app.Activity.performCreate(Activity.java:5372)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1104)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2257)
04-16 11:27:17.175: E/AndroidRuntime(31658): ... 11 more
04-16 11:27:17.175: E/AndroidRuntime(31658): Caused by: java.lang.ClassNotFoundException: Didn't find class "android.view.progressbar" on path: /data/app/com.applicationnfclogin-1.apk
04-16 11:27:17.175: E/AndroidRuntime(31658): at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:64)
04-16 11:27:17.175: E/AndroidRuntime(31658): at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
04-16 11:27:17.175: E/AndroidRuntime(31658): at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.view.LayoutInflater.createView(LayoutInflater.java:565)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.view.LayoutInflater.onCreateView(LayoutInflater.java:658)
04-16 11:27:17.175: E/AndroidRuntime(31658): at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:66)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.view.LayoutInflater.onCreateView(LayoutInflater.java:675)
04-16 11:27:17.175: E/AndroidRuntime(31658): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:700)
04-16 11:27:17.175: E/AndroidRuntime(31658): ... 21 more
04-16 11:27:37.400: D/AndroidRuntime(32009): Shutting down VM
04-16 11:27:37.400: W/dalvikvm(32009): threadid=1: thread exiting with uncaught exception (group=0x41c4c700)
（我知道它的雷區） 請參閱下面的登錄頁面代碼：
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import org.apache.http.HttpResponse;
import org.json.JSONException;
import org.json.JSONObject;
import android.app.Activity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.TextView;
import com.applicationnfclogin.R;
import android.widget.TextView;
import com.applicationnfclogin.internal.DatabaseHandler;
import com.applicationnfclogin.internal.JSONParser;
import com.applicationnfclogin.internal.NFCHandler;
import com.applicationnfclogin.internal.UserFunctions;
import android.app.ProgressDialog;
public class LoginActivity extends Activity{
private
//NfcAdapter Nfc;
Button btnLogin;
Button btnNfcScan;
Button btnLinkToRegister;
EditText inputUsername;
EditText inputPassword;
TextView loginErrorMsg;
ProgressDialog pDialog;
JSONParser jsonParser = new JSONParser();
private ProgressBar progress;
private ProgressBar progress2;
private TextView text;
// JSON Response node names
private static String KEY_SUCCESS = "success";
private static String KEY_ERROR = "error";
private static String KEY_ERROR_MSG = "error_msg";
private static String KEY_UID = "uid";
private static String KEY_FIRSTNAME = "Firstname";
private static String KEY_LASTNAME = "Lasrname";
private static String KEY_USERNAME = "Username";
private static String KEY_PASSWORD = "password";
private static String KEY_EMAIL = "email";
private static String KEY_CREATED_AT = "created_at ";
@Override
public void onCreate (Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
progress = (ProgressBar) findViewById(R.id.progressBar1);
progress2 = (ProgressBar) findViewById(R.id.progressBar2);
text = (TextView) findViewById(R.id.textView1);
//Nfc = NfcAdapter.getDefaultAdapter(null);
//Importing all assets like buttons, text fields
inputUsername = (EditText) findViewById(R.id.loginUsername);
inputPassword = (EditText) findViewById(R.id.loginPassword);
btnLogin = (Button) findViewById (R.id.btnLogin);
btnLinkToRegister = (Button) findViewById (R.id.btnLinkToRegisterScreen);
loginErrorMsg = (TextView) findViewById (R.id.login_error);
// Login button Click Event
btnLogin.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
//TODO Auto-generated method stub
String Username = inputUsername.getText().toString();
String password = inputPassword.getText().toString();
Runnable runnable = new Runnable(){
@Override
public void run() {
for (int i = 0; i <= 10; i++) {
final int value = i;
checklogin();
progress.post(new Runnable() {
@Override
public void run() {
text.setText("Loading");
progress.setProgress(value);
}
});
}
}
};
new Thread(runnable).start();
LoggingTask task = new LoggingTask();
task.execute(Username, password);
}
private void checklogin() {
try {
Thread.sleep(200);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
/*
* User logged in task
*/
class LoggingTask extends AsyncTask<String, String, String> {
@Override
protected String doInBackground(String...params) {
UserFunctions userFunctions = new UserFunctions();
JSONParser jParser = new JSONParser();
JSONObject json = userFunctions.loginUser(KEY_USERNAME, KEY_PASSWORD);
try{
if (!KEY_USERNAME.equals(KEY_USERNAME) &&!KEY_PASSWORD.equals(KEY_PASSWORD)) {
loginErrorMsg.setText("");
String res = json.getString(KEY_SUCCESS);
if(Integer.parseInt(res) ==1) {
DatabaseHandler db = new DatabaseHandler(getApplicationContext());
JSONObject json_user = json.getJSONObject("user");
db.addUser(json_user.getString(KEY_FIRSTNAME), json_user.getString(KEY_LASTNAME), json_user.getString(KEY_USERNAME), json_user.getString(KEY_UID), json_user.getString(KEY_EMAIL), json_user.getString(KEY_CREATED_AT));
Intent dashboard = new Intent (getApplicationContext(), DashboardActivity.class);
dashboard.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(dashboard);
}else{ loginErrorMsg.setText("Incorrect Username and or Password");
}
}
} catch (JSONException e) {
e.printStackTrace();
}
return null;
}
}
});
// Link to Register Screen
btnLinkToRegister.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Runnable runnable = new Runnable(){
@Override
public void run() {
for (int i = 0; i <= 10; i++) {
final int value = i;
Register();
progress.post(new Runnable() {
@Override
public void run() {
text.setText("loading");
progress.setProgress(value);
}
});
}
}
};
new Thread(runnable).start();
}
private void Register() {
try {
Thread.sleep(2000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
{
Intent i = new Intent(getApplicationContext(),
RegisterActivity.class);
startActivity(i);
finish();
}
});
}
}
主要頁面（儀表盤）：
package com.applicationnfclogin;
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.View;
import android.widget.Button;
import android.os.AsyncTask;
import com.applicationnfclogin.R;
import com.applicationnfclogin.internal.NFCHandler;
import com.applicationnfclogin.internal.UserFunctions;
public class DashboardActivity extends Activity {
UserFunctions userFunctions;
Button btnLogout;
Button btnNfcScan;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_dashboard);
btnNfcScan = (Button) findViewById(R.id.btnNfcScan);
/**Dashboard Screen for the application * */
// Check login status in database
userFunctions = new UserFunctions();
CheckLoginTask task = new CheckLoginTask();
task.execute();
}
/*
* CHeck user logged in task
*/
private class CheckLoginTask extends AsyncTask<Void, Void, Boolean> {
@Override
protected Boolean doInBackground(Void...nothing) {
return userFunctions.isUserLoggedIn(DashboardActivity.this);
}
@Override
protected void onPostExecute(Boolean result) {
if(result){
// user already logged in show databoard
//setContentView (R.layout.activity_dashboard);
btnLogout = (Button) findViewById(R.id.btnLogout);
btnLogout.setOnClickListener(new View.OnClickListener() {
public void onClick(View argo) {
userFunctions.logoutUser(getApplicationContext());
Intent login = new Intent (getApplicationContext(), LoginActivity.class);
startActivity(login);
finish();
}
});
}else{
Intent login = new Intent(getApplicationContext(), LoginActivity.class);
login.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(login);
}
// Scan
//this button is null and throws the exception
//the async task worked fine
btnNfcScan.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View argo){
Intent in = new Intent(getApplicationContext(),
NFCHandler.class);
startActivity(in);
finish();
}
});
}
}
}