我一直在做一个需要个人资料页面的应用。登录是一个活动，配置文件页面是片段。每当我进行传递时，它总是返回null。
这是我的MainActivity.java
public class MainActivity extends Activity {
ConnectionClass connectionClass;
EditText edtuserid,edtpass;
Button btnlogin;
ProgressBar pbbar;
public int test2;
public String test3 = "";
String user_fname;
String user_lname;
int dept_id;
String test;
String user_email;
String user_password;
String user_username;
Bundle profileBundle;
String userid;
String password;
int userIDD;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
connectionClass = new ConnectionClass();
edtuserid = (EditText) findViewById(R.id.edtuserid);
edtpass = (EditText) findViewById(R.id.edtpass);
btnlogin = (Button) findViewById(R.id.btnlogin);
pbbar = (ProgressBar) findViewById(R.id.pbbar);
pbbar.setVisibility(View.GONE);
edtuserid.setText(test3);
btnlogin.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
userid = edtuserid.getText().toString();
password = edtpass.getText().toString();
DoLogin doLogin = new DoLogin();
doLogin.execute("");
}
});
}
public class DoLogin extends AsyncTask<String,String,String>
{
int b;
String z = "";
Boolean isSuccess = false;
@Override
public void onPreExecute() {
pbbar.setVisibility(View.VISIBLE);
}
@Override
public void onPostExecute(String r) {
pbbar.setVisibility(View.GONE);
if(isSuccess) {
//DITO ANG REDIRECTION
Intent base = new Intent(MainActivity.this, OtherActivity.class);
startActivity(base);
finish();
}
}
@Override
public String doInBackground(String... params) {
if(userid.trim().equals("")|| password.trim().equals(""))
z = "Please enter User Id and Password";
else
{
try {
Connection con = connectionClass.CONN();
if (con == null) {
z = "Error in connection with SQL server";
} else {
String query = "select user_id, user_fname, user_lname, department_id, user_email, user_password, user_username from users where user_id='" + userid + "' and user_password='" + password + "'";
Statement stmt = con.createStatement();
ResultSet rs = stmt.executeQuery(query);
if(rs.next())
{
userIDD = rs.getInt(1);
Bundle profileBundle = new Bundle();
profileBundle.putInt("userID", userIDD);
PathfinderAdd fragobj = new PathfinderAdd();
fragobj.setArguments(profileBundle);
z = "The ID is " + userIDD;
isSuccess=true;
}
else
{
z = "Invalid Credentials";
isSuccess = false;
}
}
}
catch (Exception ex)
{
isSuccess = false;
z = "Error Somewhere";
Log.e("MYAPP", "exception", ex);
}
}
return z;
}
}
public String getMyData() {
String test4 = test3;
return test4;
}
}
在片段中，我将数据检索为：
PathfinderAdd.java
public class PathfinderAdd extends Fragment {
ConnectionClass connectionClass;
EditText edtideaname, edtbenefit,edtobservation,edtquickwin,targetdate;
Button btnadd;
TextView targettv;
Spinner spinner1, spinner2;
ProgressBar pbbar;
String proid;
CalendarView calendar;
String realDate;
String DAY;
Date targ = null;
String finalDate;
SimpleDateFormat timeFormat;
java.sql.Date sql;
Date date2;
int userID = 0;
int user = 0;
public PathfinderAdd(){}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.addpathfinder, container, false);
connectionClass = new ConnectionClass();
edtideaname = (EditText) rootView.findViewById(R.id.edtideaname);
edtbenefit = (EditText) rootView.findViewById(R.id.edtbenefit);
edtobservation = (EditText) rootView.findViewById(R.id.edyobservation);
edtquickwin = (EditText) rootView.findViewById(R.id.edtquickwin);
targetdate = (EditText) rootView.findViewById(R.id.target);
spinner1 = (Spinner) rootView.findViewById(R.id.spinner1);
spinner2 = (Spinner) rootView.findViewById(R.id.spinner2);
btnadd = (Button) rootView.findViewById(R.id.btnadd);
pbbar = (ProgressBar) rootView.findViewById(R.id.pbbar);
targettv = (TextView) rootView.findViewById(R.id.tvtarget);
pbbar.setVisibility(View.GONE);
calendar = (CalendarView) rootView.findViewById(R.id.calendar1);
proid = "";
//String userId = ((MainActivity)getActivity()).IDD;
MainActivity getID = new MainActivity();
String IDD = getID.getMyData();
Toast.makeText(PathfinderAdd.this.getActivity(), IDD, Toast.LENGTH_SHORT).show();
btnadd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
AddPro addPro = new AddPro();
addPro.execute("");
}
});
calendar.setOnDateChangeListener(new OnDateChangeListener() {
public void onSelectedDayChange(CalendarView view, int year_date, int month_date,
int dayOfMonth) {
int day = dayOfMonth;
int month = month_date;
int year = year_date;
DAY=String.valueOf(year)+String.valueOf(month)+String.valueOf(day);
}
});
return rootView;
}
public class AddPro extends AsyncTask<String, String, String> {
String z = "";
Boolean isSuccess = false;
String observation = edtobservation.getText().toString();
String quickwin = edtquickwin.getText().toString();
String ideaname = edtideaname.getText().toString();
String benefit = edtbenefit.getText().toString();
String target_date = targetdate.getText().toString();
String process = spinner1.getSelectedItem().toString();
String benefitType = spinner2.getSelectedItem().toString();
String lol = "2015-11-28";
Integer benefit_type = spinner2.getSelectedItemPosition();
Integer idea_type = spinner1.getSelectedItemPosition();
Integer idea_id;
Integer benefit_id;
Integer pathfinder_id = 1;
Integer pathfinder_status = 9;
Integer pathfinder_prog = 0;
@Override
protected void onPreExecute() {
pbbar.setVisibility(View.VISIBLE);
}
@Override
protected void onPostExecute(String r) {
pbbar.setVisibility(View.GONE);
Toast.makeText(PathfinderAdd.this.getActivity(), r, Toast.LENGTH_SHORT).show();
if(isSuccess==true) {
edtideaname.setText(null);
edtbenefit.setText(null);
edtobservation.setText(null);
edtquickwin.setText(null);
targetdate.setText(null);
}
}
@Override
protected String doInBackground(String... params) {
if (ideaname.trim().equals("") || benefit.isEmpty() || observation.trim().equals("") || quickwin.trim().equals(""))
z = "Please fill all the fields";
else {
try {
Connection con = connectionClass.CONN();
if (con == null) {
z = "Error in connection with SQL server";
} else {
//timeFormat = new SimpleDateFormat("yyyy-MM-dd",Locale.ENGLISH);
//finalDate = timeFormat.format(targ);
//sql = new java.sql.Date(targ.getTime());
int lol=1;
double benefitInt = Double.parseDouble(benefit);
date2 = new SimpleDateFormat("yyyyMMdd", Locale.ENGLISH).parse(DAY);
String newDateString = new SimpleDateFormat("yyyy/MM/dd",Locale.ENGLISH).format(date2);
DateFormat format2 = new SimpleDateFormat("yyyy/MM/dd", Locale.ENGLISH);
Date date3 = format2.parse(newDateString);
String dates = new SimpleDateFormat("yyyy/MM/dd", Locale.ENGLISH)
.format(Calendar.getInstance().getTime());
//String date = new SimpleDateFormat("yyyy/MM/dd", Locale.ENGLISH)
//.format(calendar.getDate());
switch (idea_type)
{
case 0:
idea_id = 1;
break;
case 1:
idea_id = 2;
break;
case 2:
idea_id = 3;
break;
case 3:
idea_id = 4;
break;
case 4:
idea_id = 5;
break;
default:
idea_id = 1;
break;
}
switch(benefit_type)
{
case 0:
benefit_id = 1;
break;
case 1:
benefit_id = 2;
break;
default:
benefit_id = 1;
break;
}
String query = "insert into pathfinder (pathfinder_id,pathfinder_name,idea_id,benefit_id,pathfinder_potential_eqv,pathfinder_observation,pathfinder_quickwin,pathfinder_target_closure,pathfinder_status,pathfinder_progress,patfinder_actual_closure,pathfinder_date_raised,user_id)" +
"values ('" +pathfinder_id+ "','" +ideaname+ "','" +idea_id+ "','" +benefit_id+ "','" +benefitInt+ "','" +observation+ "','" +quickwin+ "','" +dates+ "','" +pathfinder_status+ "','" +pathfinder_prog+ "','" +dates+ "','" +dates+ "','" + user+"')";
PreparedStatement preparedStatement = con.prepareStatement(query);
preparedStatement.executeUpdate();
z = "Added Successfully";
isSuccess = true;
}
} catch (Exception ex) {
isSuccess = false;
z = "Exceptions";
Log.e("MYAPP", "exception", ex);
}
}
return z;
}
}
}
问题是无论何时执行此代码，我都会得到一个空值。我也尝试将它分配给一个方法，但它仍然返回null。
答案 0 :(得分：1)
你必须使用相同的对象去片段。我认为你使用了另一个片段对象进行交易，这就是为什么它显示为空。
它必须有点像这样
--recursive答案 1 :(得分：0)
如果您使用静态片段，setArguments()根本无法工作。在beginTransaction()中执行fragmentManager之前，您需要为事务设置参数。如果你在那之后再做，那么setArguments()也不会工作
答案 2 :(得分：0)
您也可以在不将数据传递给片段的情况下执行此操作。您可以直接从主Activity中获取数据。在您的主要活动中，只需执行此操作。
if(rs.next())
{
userIDD = rs.getInt(1);
user_fname = rs.getString(2);
user_lname = rs.getString(3);
dept_id = rs.getInt(4);
user_email = rs.getString(5);
user_password = rs.getString(6);
user_username = rs.getString(7);
}
然后在你的片段中得到这样的值：
userId = ((YourActivity)getActivity()).userIDD;
确保您的变量是全球活动。