我想将一个对象数组列表从一个 Activity 发送到另一个 Activity 。我正在使用 Parcelable 扩展我的对象类，并使用 intent onActivityResult 传输列表。
但列表在第二个 Activity 中显示为空。
第一个 Activity :
public class PlanEventActivity extends AppCompatActivity implements TimePickerDialog.OnTimeSetListener,
DatePickerDialog.OnDateSetListener{
private boolean mHoursMode;
RelativeLayout chooseEvent,time,date;
EditText eventName;
TextView timeTextView,dateTextView,chooseEventText;
static final int CUSTOM_DIALOG_ID = 0;
ListView dialog_ListView;
private ImageView addOrganizer;
static final int PICK_CONTACT_REQUEST = 1;
private ArrayList<contact> mSelectedContacts;
private ListViewAdapter mAdapter;
private ListView mContactsList;
private ArrayList<Integer> selectedItemsPositions;
private boolean mContactListActivity;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_plan_event);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
toolbar.setTitle("");
TextView toolbarTitle = (TextView) toolbar.findViewById(R.id.toolbar_title);
toolbarTitle.setText("MeaVita");
setSupportActionBar(toolbar);
setUpUI();
mAdapter = new ListViewAdapter(this,mSelectedContacts);
mContactsList.setAdapter(mAdapter);
mAdapter.setMode(Attributes.Mode.Single);
mContactsList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
((SwipeLayout)(mContactsList.getChildAt(position - mContactsList.getFirstVisiblePosition()))).open(true);
}
});
}
public void setUpUI()
{
chooseEvent = (RelativeLayout)findViewById(R.id.chooseEventLayout);
time = (RelativeLayout)findViewById(R.id.timeLayout);
date = (RelativeLayout)findViewById(R.id.dateLayout);
eventName = (EditText)findViewById(R.id.editTextEventName);
timeTextView = (TextView)findViewById(R.id.timeTextView);
dateTextView = (TextView)findViewById(R.id.dateTextView);
chooseEventText = (TextView)findViewById(R.id.chooseEventTextView);
addOrganizer = (ImageView)findViewById(R.id.addOrganizer);
mContactsList = (ListView)findViewById(R.id.selectedContactsList);
mSelectedContacts = new ArrayList<>();
contact contact = new contact();
contact.setContactid("1");
contact.setContactName("sid");
mSelectedContacts.add(contact);
contact.setContactid("2");
contact.setContactName("ssss");
mSelectedContacts.add(contact);
addOrganizer.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent pickContactIntent = new Intent(PlanEventActivity.this,ContactList.class);
startActivityForResult(pickContactIntent, PICK_CONTACT_REQUEST);
}
});
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// Check which request we're responding to
if (requestCode == PICK_CONTACT_REQUEST) {
// Make sure the request was successful
if (resultCode == RESULT_OK) {
Bundle bundle = data.getExtras();
mContactListActivity = bundle.getBoolean("contactListActivity",true);
mSelectedContacts = bundle.getParcelableArrayList("selectedContacts");
}
if(mContactListActivity)
{
addOrganizer.setVisibility(View.INVISIBLE);
mContactsList.setVisibility(View.VISIBLE);
}
else {
mContactsList.setVisibility(View.GONE);
}
}
}
第二个 Activity :
public class ContactList extends AppCompatActivity {
private ArrayList<contact> contact_list = null;
private contactAdapter mContactAdapter = null;
private ArrayList<contact> items;
private ArrayList<contact> selectedContacts;
boolean[] isChecked;
Cursor mCursor;
ListView lv;
public int RQS_PICK_CONTACT = 1;
private static final int PERMISSIONS_REQUEST_READ_CONTACTS = 100;
ArrayList<Integer> selectedItemsPositions;
private ImageView done;
private boolean mContactListActivity;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_contacts_list);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
toolbar.setTitle("");
TextView toolbarTitle = (TextView) toolbar.findViewById(R.id.toolbar_title);
toolbarTitle.setText("Select Contacts");
setSupportActionBar(toolbar);
done = (ImageView)findViewById(R.id.done);
contact_list = new ArrayList<contact>();
selectedContacts = new ArrayList<contact>();
lv = (ListView)findViewById(R.id.list);
showContacts();
done.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Log.d("selectd",String.valueOf(selectedItemsPositions));
mContactListActivity = true;
selectedContacts = new ArrayList<>();//to store selected items
for (Integer pos : selectedItemsPositions) {
selectedContacts.add(items.get(pos));
}
Intent i = new Intent(ContactList.this,PlanEventActivity.class);
Bundle b = new Bundle();
b.putSerializable("selectedContacts",(Serializable) selectedContacts);
i.putExtras(b);
setResult(RESULT_OK, i);
finish();
}
});
}
@SuppressWarnings("unused")
private void getContacts() {
String[] projection = new String[] {
ContactsContract.Contacts.DISPLAY_NAME,
ContactsContract.Contacts.HAS_PHONE_NUMBER,
ContactsContract.Contacts._ID };
mCursor = managedQuery(ContactsContract.Contacts.CONTENT_URI, null, null, null,null);
while (mCursor.moveToNext()) {
contact contact = new contact();
String contactId = mCursor.getString(mCursor.getColumnIndex(ContactsContract.Contacts._ID));
contact.setContactid(mCursor.getString(mCursor.getColumnIndex(ContactsContract.Contacts._ID)));
contact.setContactName(mCursor.getString(mCursor.getColumnIndex(ContactsContract.Contacts.DISPLAY_NAME)));
contact_list.add(contact);
}
isChecked = new boolean[mCursor.getCount()];
for (int i = 0; i < isChecked.length; i++) {
isChecked[i] = false;
}
this.mContactAdapter = new contactAdapter(this, R.layout.contact_list_item, contact_list);
lv.setAdapter(this.mContactAdapter);
// mCursor.close();
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
// TODO Auto-generated method stub
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == RQS_PICK_CONTACT) {
if (resultCode == RESULT_OK) {
getContacts();
}
}
}
public class contactAdapter extends ArrayAdapter<contact> {
public contactAdapter(Context context, int textViewResourceId, ArrayList<contact> items1) {
super(context, textViewResourceId, items1);
items = items1;
selectedItemsPositions = new ArrayList<>();
}
//to store all selected items position
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
final ViewHolder mViewHolder;
if (convertView == null) {
mViewHolder = new ViewHolder();
LayoutInflater vi = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
convertView = vi.inflate(R.layout.contact_list_item, parent, false);
mViewHolder.cb = (CheckBox) convertView.findViewById(R.id.checkBox);
mViewHolder.name = (TextView) convertView.findViewById(R.id.name);
mViewHolder.cb.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView, boolean ischecked) {
int position = (int) mViewHolder.cb.getTag();
if (ischecked) {
//check whether its already selected or not
if (!selectedItemsPositions.contains(position))
selectedItemsPositions.add(position);
} else {
//remove position if unchecked checked item
selectedItemsPositions.remove((Object) position);
}
}
});
convertView.setTag(mViewHolder);
} else {
mViewHolder = (ViewHolder) convertView.getTag();
}
contact contacts = items.get(position);
mViewHolder.cb.setTag(position);
if (selectedItemsPositions.contains(position))
mViewHolder.cb.setChecked(true);
else
mViewHolder.cb.setChecked(false);
mViewHolder.name.setText(contacts.getContactName());
return convertView;
}
public class ViewHolder {
CheckBox cb;
TextView name;
}
}
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions,
int[] grantResults) {
if (requestCode == PERMISSIONS_REQUEST_READ_CONTACTS) {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// Permission is granted
getContacts();
} else {
Toast.makeText(this, "Until you grant the permission, we canot display the names", Toast.LENGTH_SHORT).show();
}
}
}
private void showContacts()
{
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && checkSelfPermission(Manifest.permission.READ_CONTACTS) != PackageManager.PERMISSION_GRANTED) {
requestPermissions(new String[]{Manifest.permission.READ_CONTACTS}, PERMISSIONS_REQUEST_READ_CONTACTS);
//After this point you wait for callback in onRequestPermissionsResult(int, String[], int[]) overriden method
}
else {
getContacts();
}
}
}
项目等级:
public class contact implements Parcelable {
private String contactName;
private String contactId;
contact(){}
contact(String contactId,String contactName)
{
this.contactId = contactId;
this.contactName = contactName;
}
public contact(Parcel in) {
this();
contactId = in.readString();
contactName = in.readString();
}
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(contactId);
dest.writeString(contactName);
}
public static final Parcelable.Creator<contact> CREATOR = new Parcelable.Creator<contact>()
{
public contact createFromParcel(Parcel in)
{
return new contact(in);
}
public contact[] newArray(int size)
{
return new contact[size];
}
};
public int describeContents() {
// TODO Auto-generated method stub
return 0;
}
public String getContactName() {
return contactName;
}
public void setContactName(String contactName) {
this.contactName = contactName;
}
public String getContactid() {
return contactId;
}
public void setContactid(String contactId) {
this.contactId = contactId;
}
}
不明白哪里出了问题。谁能帮忙。谢谢..
最佳答案
当您收到 startActivityForResult() 调用的结果时，结果 Intent 将作为最后一个传递到 onActivityResult() 方法中范围。您正在使用从 getIntent() 返回的 Intent，这是用于启动当前 Activity 的 Intent , 所以它不会有你正在寻找的额外内容。
在 onActivityResult() 中，从传递给方法的 data Intent 中获取 Bundle。
Bundle bundle = data.getExtras();
您还需要在 onActivityResult() 中删除这一行:
mSelectedContacts = bundle.getParcelableArrayList("selectedContacts");
并将其替换为:
ArrayList<contact> newContacts = bundle.getParcelableArrayList("selectedContacts");
mSelectedContacts.addAll(newContacts);
mAdapter.notifyDataSetChanged();
并确保您已将 ContactList 中的 b.putSerializable() 调用更改为 b.putParcelableArrayList("selectedContacts", selectedContacts).
关于java - 使用 Parcelable 在 Activity 之间发送对象数组列表，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/37222728/