我想从ListView另一个活动中发送数据并将这些数据保存到SQLiteDatabase. 我使用ListView并将用户数据保存到SQLite并将此数据设置为ListView，我希望在单击列表视图项目时，将用户信息显示到另一个活动中。但告诉我这个错误：
java.lang.NumberFormatException: Invalid int: "null"
主页代码：
public class Example_mainPage extends AppCompatActivity {
private ListView list_phoneBook;
private dbOpenHelper_ex dbOpen_ex;
private dbHandler_ex dbhandler_ex;
private String[] nameArray;
private int[] list_id;
private Button insert_ex_btn, update_ex_btn, delete_ex_btn;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.example_main_page);
dbhandler_ex = new dbHandler_ex(this);
list_phoneBook = (ListView) findViewById(R.id.phoneBook_list);
list_phoneBook.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent con_intent = new Intent(Example_mainPage.this, EX_Contacts_Page.class);
con_intent.putExtra("id_show", list_id[position]);
startActivity(con_intent);
}
});
insert_ex_btn = (Button) findViewById(R.id.btn_insert_ex);
insert_ex_btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent insert_intent = new Intent(Example_mainPage.this, EX_Insert_Page.class);
startActivity(insert_intent);
}
});
/*
update_btn = (Button) findViewById(R.id.btn_update);
update_btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
dbhandler_ex.open();
dbhandler_ex.update("Maryam", 1, 4);
dbhandler_ex.close();
}
});
delete_btn = (Button) findViewById(R.id.btn_delete);
delete_btn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
dbhandler_ex.open();
dbhandler_ex.delete(2);
dbhandler_ex.close();
}
});*/
}
@Override
protected void onResume() {
super.onResume();
refresh();
}
public void refresh() {
dbhandler_ex.open();
int count = dbhandler_ex.count();
nameArray = new String[count];
list_id = new int[count];
for (int i = 0; i < count; i++) {
nameArray[i] = dbhandler_ex.display(i, 1) + "\n" + dbhandler_ex.display(i, 2);
list_id[i] = Integer.parseInt(dbhandler_ex.display(i, 0));
}
dbhandler_ex.close();
list_phoneBook.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, nameArray));
}
}
联系人页面代码：
public class EX_Contacts_Page extends AppCompatActivity {
private dbHandler_ex dbHandlerEx;
private TextView name_ex_contacts, family_ex_contacts, address_ex_contacts, email_ex_contacts, phone_ex_contacts;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.ex_contacts__page);
dbHandlerEx = new dbHandler_ex(this);
Bundle extraBundle = getIntent().getExtras();
String list_id = extraBundle.getString("id_show");
name_ex_contacts = (TextView) findViewById(R.id.ex_contacts_name);
family_ex_contacts = (TextView) findViewById(R.id.ex_contacts_family);
address_ex_contacts = (TextView) findViewById(R.id.ex_contacts_address);
email_ex_contacts = (TextView) findViewById(R.id.ex_contacts_email);
phone_ex_contacts = (TextView) findViewById(R.id.ex_contacts_phone);
dbHandlerEx.open();
name_ex_contacts.setText(dbHandlerEx.display_id(Integer.parseInt(list_id), 1));
family_ex_contacts.setText(dbHandlerEx.display_id(Integer.parseInt(list_id), 2));
address_ex_contacts.setText(dbHandlerEx.display_id(Integer.parseInt(list_id), 3));
email_ex_contacts.setText(dbHandlerEx.display_id(Integer.parseInt(list_id), 4));
phone_ex_contacts.setText(dbHandlerEx.display_id(Integer.parseInt(list_id), 5));
dbHandlerEx.close();
}
public void ex_update(View view){
}
public void ex_delete(View view){
}
}
dbHandler 代码：
public class dbHandler_ex {
private dbOpenHelper_ex dbOpen;
private SQLiteDatabase database;
public dbHandler_ex(Context context) {
dbOpen = new dbOpenHelper_ex(context);
}
public void open() {
database = dbOpen.getWritableDatabase();
}
public void close() {
dbOpen.close();
}
public String display(int position, int field) {
Cursor cursor = database.query(dbOpen.tblName, null, null, null, null, null, null);
cursor.moveToPosition(position);
String user_field = cursor.getString(field);
return user_field;
}
public String display_id(int id, int field) {
Cursor cursor = database.rawQuery("SELECT * FROM tbl_phonebook WHERE id="+id, null);
cursor.moveToFirst();
String user_field = cursor.getString(field);
return user_field;
}
public void insert(String name, String family, String address, String email, String phone) {
ContentValues contentValues = new ContentValues();
contentValues.put(dbOpen.cName, name);
contentValues.put(dbOpen.cFamily, family);
contentValues.put(dbOpen.cAddress, address);
contentValues.put(dbOpen.cEmail, email);
contentValues.put(dbOpen.cPhone, phone);
database.insert(dbOpen.tblName, dbOpen.cName, contentValues);
}
public Integer count() {
Cursor cursor = database.query(dbOpen.tblName, null, null, null, null, null, null);
int count_num = cursor.getCount();
return count_num;
}
public void delete(int id) {
database.delete(dbOpen.tblName, "id=" + id, null);
}
public void update(String value, int field, int id) {
ContentValues contentValues = new ContentValues();
database.update(dbOpen.tblName, contentValues, "id=" + id, null);
}
}
LogCat 错误：
02-02 15:20:46.474 22609-22609/com.tellfa.nikandroid.database E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.tellfa.nikandroid.database, PID: 22609
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.tellfa.nikandroid.database/com.tellfa.nikandroid.database.example.EX_Contacts_Page}: java.lang.NumberFormatException: Invalid int: "null"
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2331)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2391)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1309)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5349)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703)
Caused by: java.lang.NumberFormatException: Invalid int: "null"
at java.lang.Integer.invalidInt(Integer.java:138)
at java.lang.Integer.parseInt(Integer.java:358)
at java.lang.Integer.parseInt(Integer.java:334)
at com.tellfa.nikandroid.database.example.EX_Contacts_Page.onCreate(EX_Contacts_Page.java:32)
at android.app.Activity.performCreate(Activity.java:6020)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1105)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2284)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2391)
at android.app.ActivityThread.access$800(ActivityThread.java:151)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1309)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:135)
at android.app.ActivityThread.main(ActivityThread.java:5349)
at java.lang.reflect.Method.invoke(Native Method)
at java.lang.reflect.Method.invoke(Method.java:372)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:908)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:703)
我怎样才能适应它？tnx 全部 <3