我尝试登录时，我的应用程序出现问题。
事实上，如果我注册（如果注册表操作上的复选框remerberMe isChecked()，则在下次连接时显示主要活动，否则显示登录活动），首先，它可以正常工作。
但是，Login活动在注册操作后在下一个连接上调用时不起作用。
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.login);
setTitle(R.string.loginTitle);
// Importing all assets like buttons, text fields
inputUsername = (EditText) findViewById(R.id.username_value);
inputPassword = (EditText) findViewById(R.id.password_value);
btnLogin = (Button) findViewById(R.id.loginButton);
btnExit = (Button) findViewById(R.id.exitButton);
btnLinkToRegister = (Button) findViewById(R.id.btnLinkToRegister);
rememberMe = (CheckBox) findViewById(R.id.rememberNameRegister);
// Login button Click Event
btnLogin.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
LoginAction();
}
});
// Link to Register Screen
btnLinkToRegister.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent i = new Intent(getApplicationContext(),
RegisterActivity.class);
startActivity(i);
finish();
}
});
btnExit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
finish();
}
});
}
public void LoginAction() {
Log.i("Login", "Login Action");
progressDialog = ProgressDialog.show(LoginActivity.this, null,
getResources().getString(R.string.loginProgressMessage), true);
// try {
runOnUiThread(new Runnable() {
String username = inputUsername.getText().toString();
String password = inputPassword.getText().toString();
@Override
public void run() {
Log.i("Login Run", "username " + username);
switch (username.length()) {
case 0:
blankUserName();
break;
}
switch (password.length()) {
case 0:
blankPassWord();
// thread.stop();
break;
}
try {
if (username.length() > 0 && password.length() > 0) {
Log.i("Login Run", "password " + password);
// Password pass = new Password(username, password);
DatabaseHelper db = new DatabaseHelper(
getApplicationContext());
int count = db.getRowCount();
Log.i("Login", "getRowCompte " + count);
if (count == 1) {
Log.i("Login","getLogin1 ");
// if (db.getLogin(username, password) == 1) {
if (db.Login(username, password)== true) {
Log.i("Login", "rememberMe.isChecked()");
if (rememberMe.isChecked() == true) {
statut = "on";
} else if (rememberMe.isChecked() == false) {
statut = "off";
}
Log.i("Login", "ok ischecked");
Log.i("Login","getRowCompteStat "+ db.getRowCountStat());
if (db.getRowCountStat() == 1) {
db.UpdateStatut(statut);
Log.i("Login", "getRowCompte " + count);
}
Toast.makeText(getApplicationContext(),
"Student Moyenne \n Bienvenu!",
Toast.LENGTH_LONG).show();
Log.i("Login Run", "Connecté");
Intent moy = new Intent(
getApplicationContext(),
MoyenneMain.class);
// Close all views before launching
// Dashboard
moy.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(moy);
finish();
db.close();
} else if (db.Login(username, password)==false){
// if (db.getLogin(username, password) == 0) {
// Log.i("Login Run", "faux password");
Toast.makeText(LoginActivity.this,"Invalid Username/Password",Toast.LENGTH_LONG).show();
Intent login = new Intent(getApplicationContext(),LoginActivity.class);
login.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(login);
finish();
db.close();
}
} else if (count == 0) {
Log.i("Login Run", "Enregistrez vous");
Toast.makeText(LoginActivity.this,
"Enregistrez vous!", Toast.LENGTH_SHORT)
.show();
Intent register = new Intent(
getApplicationContext(),
RegisterActivity.class);
register.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(register);
finish();
db.close();
}
}
} catch (Exception e) {
Log.i("Login Error1", e.getMessage());
Toast.makeText(LoginActivity.this, e.getMessage(),
Toast.LENGTH_LONG).show();
}
}
});
// } catch (Exception e) {
// Thread.currentThread().destroy();
// Log.i("Login Error2", e.getMessage());
// Toast.makeText(LoginActivity.this, e.getMessage(),
// Toast.LENGTH_LONG).show();
// }
}
private void blankUserName() {
Toast.makeText(LoginActivity.this, "Entrez un nom Utilisateur SVP!",
Toast.LENGTH_SHORT).show();
Intent login = new Intent(getApplicationContext(), LoginActivity.class);
login.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(login);
finish();
}
private void blankPassWord() {
Toast.makeText(LoginActivity.this, "Entrez un mot de passe SVP!",
Toast.LENGTH_SHORT).show();
Intent login = new Intent(getApplicationContext(), LoginActivity.class);
login.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
startActivity(login);
finish();
}
public int getRowCountStat() {
String countQuery = "SELECT * FROM " + TABLE_STATUT;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
int rowCount = cursor.getCount();
db.close();
cursor.close();
// return row count
return rowCount;
}
public int getRowCount() {
String countQuery = "SELECT * FROM " + TABLE_LOGIN;
SQLiteDatabase db = this.getReadableDatabase();
Cursor cursor = db.rawQuery(countQuery, null);
int rowCount = cursor.getCount();
db.close();
cursor.close();
// return row count
return rowCount;
}
public boolean Login(String username, String password) throws SQLException
{
Cursor mCursor = db.rawQuery("SELECT * FROM " + TABLE_LOGIN + " WHERE username=? AND password=?"
, new String[]{username,password});
if (mCursor != null) {
if(mCursor.getCount() > 0)
{
return true;
}
}
return false;
}
public int UpdateStatut(String statut) {
final static int idStat = 1;
SQLiteDatabase db = this.getWritableDatabase();
ContentValues cv = new ContentValues();
cv.put(STATUT, statut);
return db.update(TABLE_STATUT, cv, ID_STAT + "=?",
new String[] { String.valueOf(idStat) });
}
10-24 01:48:08.819: E/AndroidRuntime(29242): FATAL EXCEPTION: main
10-24 01:48:08.819: E/AndroidRuntime(29242): java.lang.NullPointerException: println needs a message
10-24 01:48:08.819: E/AndroidRuntime(29242): at android.util.Log.println_native(Native Method)
10-24 01:48:08.819: E/AndroidRuntime(29242): at android.util.Log.i(Log.java:143)
10-24 01:48:08.819: E/AndroidRuntime(29242): at com.android.moyenne.activity.LoginActivity$4.run(LoginActivity.java:163)
10-24 01:48:08.819: E/AndroidRuntime(29242): at android.app.Activity.runOnUiThread(Activity.java:3707)
10-24 01:48:08.819: E/AndroidRuntime(29242): at com.android.moyenne.activity.LoginActivity.LoginAction(LoginActivity.java:78)
10-24 01:48:08.819: E/AndroidRuntime(29242): at com.android.moyenne.activity.LoginActivity$1.onClick(LoginActivity.java:46)
10-24 01:48:08.819: E/AndroidRuntime(29242): at android.view.View.performClick(View.java:2408)
10-24 01:48:08.819: E/AndroidRuntime(29242): at android.view.View$PerformClick.run(View.java:8816)
10-24 01:48:08.819: E/AndroidRuntime(29242): at android.os.Handler.handleCallback(Handler.java:587)
10-24 01:48:08.819: E/AndroidRuntime(29242): at android.os.Handler.dispatchMessage(Handler.java:92)
10-24 01:48:08.819: E/AndroidRuntime(29242): at android.os.Looper.loop(Looper.java:123)
10-24 01:48:08.819: E/AndroidRuntime(29242): at android.app.ActivityThread.main(ActivityThread.java:4627)
10-24 01:48:08.819: E/AndroidRuntime(29242): at java.lang.reflect.Method.invokeNative(Native Method)
10-24 01:48:08.819: E/AndroidRuntime(29242): at java.lang.reflect.Method.invoke(Method.java:521)
10-24 01:48:08.819: E/AndroidRuntime(29242): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
10-24 01:48:08.819: E/AndroidRuntime(29242): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
10-24 01:48:08.819: E/AndroidRuntime(29242): at dalvik.system.NativeStart.main(Native Method)
10-24 01:48:12.260: I/Process(29242): Sending signal. PID: 29242 SIG: 9
答案 0 :(得分：9)
在catch区块中e.getMessage()可能是null。试试这个：
String msg = (e.getMessage()==null)?"Login failed!":e.getMessage();
Log.i("Login Error1",msg);
答案 1 :(得分：0)
图像是你的imageView和imageurl是你的服务器上的toload图像的网址。
try {
InputStream in = new java.net.URL(imageURl).openStream();
this.image = BitmapFactory.decodeStream(in);
} catch (Exception e) {
String msg = (e.getMessage() == null) ? "image load failed!" :e.getMessage();
Log.i("image load error", msg);
}