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在我的主类中，我有一个按钮来调用一个显示带有edittext对话框的类。我的问题是这样的 - 主要活动在第一次运行时没有获得edittext值，如果我第二次运行它，我会得到旧的edittext值。无法访问不同类中的值
看来主要的活动类执行完整的代码块并返回存储在类中的前一个值，我尝试了许多方法，包括共享首选项。
MainActivity.java
public class MainActivity extends Activity {
EditText comment_et,input_et;
Spinner spinner;
Button addbutton,reportbut;
String input_string,date,time,comment,item;
TextView date_tv,time_tv;
String temp[];
Datas datatemp;
String savedinput;
ArrayList<String> list = new ArrayList<String>();
ArrayAdapter<String> adapter;
DatabaseHandler db = new DatabaseHandler(this);
@Override
protected void onCreate(Bundle savedInstanceState)
{
SharedPreferences prefs = getSharedPreferences("myprefs", 0);
savedinput= prefs.getString("KEY_SAVEDINPUT","");
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
spinner = (Spinner)findViewById(R.id.spin1);
input_et = (EditText)findViewById(R.id.input_et);
addbutton = (Button)findViewById(R.id.addbutton);
reportbut = (Button)findViewById(R.id.report);
comment_et = (EditText)findViewById(R.id.comment_et);
adapter = new ArrayAdapter<String>(this, android.R.layout.simple_spinner_item, list);
date_tv = (TextView)findViewById(R.id.date_tv);
time_tv = (TextView)findViewById(R.id.time_tv);
final Calendar c = Calendar.getInstance();
int mYear = c.get(Calendar.YEAR);
int mMonth = c.get(Calendar.MONTH);
int mDay = c.get(Calendar.DAY_OF_MONTH);
int mHour = c.get(Calendar.HOUR_OF_DAY);
int mMinute = c.get(Calendar.MINUTE);
date = ""+mDay+"/"+mMonth+1+"/"+mYear;
time = ""+mHour+":"+mMinute;
date_tv.setText(date);
time_tv.setText(time);
int max_id = db.getDatasCount();
for(int i = 1; i<max_id+1 ;i++)
{
datatemp = db.getItemOnly(i);
String s = datatemp._item.toString();
list.add(" "+ s);
}
addbutton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
AlertDialogManager alert = new AlertDialogManager();
alert.showAlertDialog(MainActivity.this, "Enter Item",
"Please enter the spinner item",
true);
System.out.println("main : " +savedinput);
}
});
reportbut.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent i = new Intent(getApplicationContext(), ListviewActivity.class);
startActivity(i);
}
});
spinner.setAdapter(adapter);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setOnItemSelectedListener(new OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> parent, View view,
int position, long id) {
item = parent.getItemAtPosition(position).toString();
}
@Override
public void onNothingSelected(AdapterView<?> arg0) {
}
});
Button submit = (Button)findViewById(R.id.save);
submit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v)
{
comment = comment_et.getText().toString();
System.out.println("comment:"+comment);
/**
* CRUD Operations
* */
// Inserting Contacts
Log.d("Insert: ", "Inserting ..");
db.addData(new Datas(item, comment, date, time));
Toast.makeText(getApplicationContext(), "Data Submitted Successfully",
Toast.LENGTH_LONG).show();
// Reading all contacts
Log.d("Reading: ", "Reading all contacts..");
List<Datas> datas = db.getAllDatas();
for (Datas d : datas) {
String log = "Id: "+d.getID()+" ,Item: " + d.getItem() + " ,Comment: " + d.getComment() + " ,Date: " + d.getDate() + ",Comment: " + d.getTime();
// Writing Contacts to log
Log.d("Item: ", log);
}
}
});
}
public void onNothingSelected(AdapterView<?> arg0) {
// TODO Auto-generated method stub
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.activity_main, menu);
return true;
}
}
AlertDialogManager.java
public class AlertDialogManager {
/**
* Function to display simple Alert Dialog
* @param context - application context
* @param title - alert dialog title
* @param message - alert message
* @param status - success/failure (used to set icon)
* - pass null if you don't want icon
* */
String savedinput;
public void showAlertDialog(final Context context, String title, String message,
Boolean status)
{
AlertDialog alertDialog = new AlertDialog.Builder(context).create();
// Setting Dialog Title
alertDialog.setTitle(title);
// Setting Dialog Message
alertDialog.setMessage(message);
//setting input
final EditText input = new EditText(context);
alertDialog.setView(input);
// saving input to a string
savedinput = input.getText().toString();
System.out.println(savedinput);
if(status != null)
// Setting alert dialog icon
alertDialog.setIcon((status) ? R.drawable.success : R.drawable.fail);
// Setting OK Button
alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
savedinput = input.getText().toString();
SharedPreferences prefs = context.getSharedPreferences("myprefs", 0);
SharedPreferences.Editor editor =prefs.edit();
editor.putString("KEY_SAVEDINPUT", savedinput);
editor.commit();
System.out.println("from class "+savedinput);
}
});
// Showing Alert Message
alertDialog.show();
}
String getItem()
{
return savedinput;
}
}
，这里是我的logcat的，只是为了进一步澄清
02-01 13:48:43.372: I/System.out(897): main : firstexecute
02-01 13:48:46.942: W/KeyCharacterMap(897): No keyboard for id 0
02-01 13:48:46.942: W/KeyCharacterMap(897): Using default keymap: /system/usr/keychars/qwerty.kcm.bin
02-01 13:48:49.532: I/System.out(897): from class secondexecute
其中u没有获得价值？ –
我没有从类中获取主要活动的值，类本身正在获取值为字符串 –