我正在编写一个简单的应用程序来保存列表中的联系人。 我的数据库工作正常，但是当我重新启动应用程序或更新联系人的详细信息时（即使我没有更新图像），所有图像都不会再次显示。
我一路上错过了什么？ 提前谢谢！
MainActivity.class
package org.intracode.contactmanager;
import android.content.Intent;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextUtils;
import android.text.TextWatcher;
import android.view.ContextMenu;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TabHost;
import android.widget.TextView;
import android.widget.Toast;
import java.net.URI;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;
public class MainActivity extends AppCompatActivity {
//live apearences in screen objects
EditText nameLine, PhoneLine, EmailLine, AddressLine;
Button addBtn;
TabHost myTab;
List<Contact> myContactList = new ArrayList<>();
ListView myListView;
ImageView contactImage;
Uri imageURI = Uri.parse("android.resource://org.intracode.contactmanager/drawable/no_logo.png");// including assigning
DatabaseHandler contacsDB;
ArrayAdapter<Contact> myContactsAdapter;
int longcClickElemnt;//clicked item position
private static final int EDIT=0,DELETE=1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//assigning line fields
nameLine = (EditText) findViewById(R.id.nameLine);
PhoneLine = (EditText) findViewById(R.id.PhoneLine);
EmailLine = (EditText) findViewById(R.id.EmailLine);
AddressLine = (EditText) findViewById(R.id.AdressLine);
addBtn = (Button) findViewById(R.id.saveButton);
//assigning tab objects
myTab = (TabHost) findViewById(R.id.tabHost); //assigning general tab
myTab.setup();
//assigning first sub tub
TabHost.TabSpec tabspec = myTab.newTabSpec("creator");
tabspec.setContent(R.id.creatorTab);
tabspec.setIndicator("Creator");//name of sub tab
myTab.addTab(tabspec);// connecting the sub tab to the general tab
// assigning second sub tub
tabspec = myTab.newTabSpec("list");
tabspec.setContent(R.id.tabContactList);
tabspec.setIndicator("List");//name of sub tab
myTab.addTab(tabspec);// connecting the sub tab to the general tab
//assigning the listview object
myListView = (ListView) findViewById(R.id.listview);
// assigning ImageView object
contactImage = (ImageView) findViewById(R.id.contactImage);
//assignig dataBase
contacsDB = new DatabaseHandler(getApplicationContext());
//register a menu for the list object
registerForContextMenu(myListView);
myListView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> adapterView, View view, int i, long l) {
longcClickElemnt=i;
contactImage.setVisibility(View.VISIBLE);
return false;
}
});
// name event
nameLine.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
String email = charSequence.toString().trim();
addBtn.setEnabled(String.valueOf(nameLine.getText()).trim().length() > 0 && isValidEmaillId(email));
}
@Override
public void afterTextChanged(Editable editable) {
}
});
// email event
EmailLine.addTextChangedListener(new TextWatcher() {
String emailString = EmailLine.getText().toString().trim();
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
String email = charSequence.toString().trim();
addBtn.setEnabled(nameLine.getText().toString().trim().length() > 0 && isValidEmaillId(email));
}
@Override
public void afterTextChanged(Editable editable) {
}
});
//buttonEvent
addBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Contact newCont = new Contact(contacsDB.getContactsCount(), nameLine.getText().toString(), PhoneLine.getText().toString(), EmailLine.getText().toString(), AddressLine.getText().toString(), imageURI);
if (!contactExist(newCont)) {
contacsDB.createContact(newCont);
myContactList.add(newCont);
myContactsAdapter.notifyDataSetChanged();// let the adapter know something is changing in our list
Toast.makeText(getApplicationContext(), "You added " + nameLine.getText().toString() + " to your contact list", Toast.LENGTH_SHORT).show();
return;
}
Toast.makeText(getApplicationContext(), nameLine.getText().toString() + " is already exist in your list", Toast.LENGTH_SHORT).show();
nameLine.setText("");
PhoneLine.setText("");
EmailLine.setText("");
AddressLine.setText("");
contactImage.setImageResource(R.drawable.no_logo);
}
});
//contactImageEvent
contactImage.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {// defining a chooser
Intent intent = new Intent();// intent is an object that passes a messeges in our system
intent.setType("image/*");// Set an explicit MIME data type.
intent.setAction(intent.ACTION_GET_CONTENT);//Allow the user to select a particular kind of data and return it.
startActivityForResult(Intent.createChooser(intent, "Select Contact Image"), 1);
}
});
//populate the list such that our list view will show all the contact that in pur database
// synchronized with our database
if (contacsDB.getContactsCount() > 0)
myContactList.addAll(contacsDB.getAllContacts());
populateList();// write the contact that we added now into the list's screen
}
//special method for the moment that we create the menu with its fields
public void onCreateContextMenu(ContextMenu myMenu, View myView,ContextMenu.ContextMenuInfo menuInfo){
super.onCreateContextMenu(myMenu,myView,menuInfo);
myMenu.setHeaderIcon(R.drawable.edit_icon);
myMenu.setHeaderTitle("Contact options");
myMenu.add(Menu.NONE,EDIT,myMenu.NONE,"Edit contact");
myMenu.add(Menu.NONE,DELETE,myMenu.NONE,"Delete contact");
}
public boolean onContextItemSelected(MenuItem myItem){
switch(myItem.getItemId()){
case EDIT:
Intent moveToEdit= new Intent(this,EditContactActivity.class);
String[] argToPass={String.valueOf(myContactList.get(longcClickElemnt).getId()),myContactList.get(longcClickElemnt).getName(),
myContactList.get(longcClickElemnt).getPhone(), myContactList.get(longcClickElemnt).getEmail(),
myContactList.get(longcClickElemnt).getAddress(),String.valueOf(myContactList.get(longcClickElemnt).getImageURI())};
moveToEdit.putExtra("args",argToPass);
startActivityForResult(moveToEdit,2);
break;
case DELETE:
//longcClickElemnt represents the position of item that we clicked on in our listview
// , initilized every setOnItemLongClickListener
contacsDB.deleteContact(myContactList.get(longcClickElemnt));//remove from database
myContactList.remove(longcClickElemnt);// remove from list
myContactsAdapter.notifyDataSetChanged();// update database instantly
break;
}
return super.onContextItemSelected(myItem);
}
//Handling the result of clicking the contact image(Created to reply startActivityForResult function )
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
switch (requestCode) {
case 1:// comeback from image collecting screen
imageURI = data.getData();
contactImage.setImageURI(data.getData());//Sets the content of this ImageView to the specified Uri.
break;
case 2://comeback from edit contact screen
String[] contactDetails=data.getStringArrayExtra("result");
contacsDB.updateContact(new Contact(Integer.parseInt(contactDetails[0]), contactDetails[1], contactDetails[2],
contactDetails[3],contactDetails[4], Uri.parse(contactDetails[5])));//update datatbase operation
myContactList.get(longcClickElemnt).setAll(contactDetails[1], contactDetails[2],
contactDetails[3],contactDetails[4], Uri.parse(contactDetails[5]));
myContactsAdapter.notifyDataSetChanged();// update database instantly
Toast.makeText(getApplicationContext(),"Changes saved!",Toast.LENGTH_SHORT).show();
break;
}
}
}
// special adapter that helps display data in a UI element, extending the array adapter class
private class ContactListAdapter extends ArrayAdapter<Contact> {
public ContactListAdapter() {
super(MainActivity.this, R.layout.contact_layout, myContactList);
}
@Override
public View getView(int position, View myView, ViewGroup parent) {//adding a contact in a certain position to our contactList screen
if (myView == null)
myView = getLayoutInflater().inflate(R.layout.contact_layout, parent, false);
Contact currContact = myContactList.get(position);
TextView name = myView.findViewById(R.id.contact_name_store);
name.setText(currContact.getName());
TextView phone = myView.findViewById(R.id.phone_store);
phone.setText(currContact.getPhone());
TextView email = myView.findViewById(R.id.email_store);
email.setText(currContact.getEmail());
TextView address = myView.findViewById(R.id.address_store);
address.setText(currContact.getAddress());
ImageView contactImage = myView.findViewById(R.id.imageViewOnLayput);
contactImage.setImageURI(currContact.getImageURI());
return myView;
}
}
// write inside myListView with the help of the adapter
private void populateList() {
myContactsAdapter = new ContactListAdapter();
myListView.setAdapter(myContactsAdapter);
}
//check if one's email address is valid
public static boolean isValidEmaillId(String email) {
return !TextUtils.isEmpty(email) && android.util.Patterns.EMAIL_ADDRESS.matcher(email).matches();
}
private boolean contactExist(Contact c) {
String c_name = c.getName();
int count = myContactList.size();
for (int i = 0; i < count; i++) {
if (myContactList.get(i).getName().compareToIgnoreCase(c_name) == 0)
return true;
}
return false;
}
}
DatabaseHandler.class
package org.intracode.contactmanager;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.net.Uri;
import java.util.ArrayList;
import java.util.List;
/**
* Created by Johnny Manson on 19.01.14.
*/
public class DatabaseHandler extends SQLiteOpenHelper {
private static final int DATABASE_VERSION = 1;
private static final String DATABASE_NAME = "contactManager",
TABLE_CONTACTS = "contacts",
KEY_ID = "id",
KEY_NAME = "name",
KEY_PHONE = "phone",
KEY_EMAIL = "email",
KEY_ADDRESS = "address",
KEY_IMAGEURI = "imageUri";
public DatabaseHandler(Context context) {
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL("CREATE TABLE " + TABLE_CONTACTS + "(" + KEY_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," + KEY_NAME + " TEXT," + KEY_PHONE + " TEXT," + KEY_EMAIL + " TEXT," + KEY_ADDRESS + " TEXT," + KEY_IMAGEURI + " TEXT)");
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("DROP TABLE IF EXISTS " + TABLE_CONTACTS);
onCreate(db);
}
public void createContact(Contact contact) {
SQLiteDatabase db = getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, contact.getName());
values.put(KEY_PHONE, contact.getPhone());
values.put(KEY_EMAIL, contact.getEmail());
values.put(KEY_ADDRESS, contact.getAddress());
values.put(KEY_IMAGEURI, String.valueOf(contact.getImageURI()));
db.insert(TABLE_CONTACTS, null, values);
db.close();
}
public Contact getContact(int id) {
SQLiteDatabase db = getReadableDatabase();
Cursor cursor = db.query(TABLE_CONTACTS, new String[] { KEY_ID, KEY_NAME, KEY_PHONE, KEY_EMAIL, KEY_ADDRESS, KEY_IMAGEURI }, KEY_ID + "=?", new String[] { String.valueOf(id) }, null, null, null, null );
if (cursor != null)
cursor.moveToFirst();
Contact contact = new Contact(Integer.parseInt(cursor.getString(0)), cursor.getString(1), cursor.getString(2), cursor.getString(3), cursor.getString(4), Uri.parse(cursor.getString(5)));
db.close();
cursor.close();
return contact;
}
public void deleteContact(Contact contact) {
SQLiteDatabase db = getWritableDatabase();
db.delete(TABLE_CONTACTS, KEY_ID + "=?", new String[] { String.valueOf(contact.getId()) });
db.close();
}
public int getContactsCount() {
SQLiteDatabase db = getReadableDatabase();
Cursor cursor = db.rawQuery("SELECT * FROM " + TABLE_CONTACTS, null);
int count = cursor.getCount();
db.close();
cursor.close();
return count;
}
public int updateContact(Contact contact) {
SQLiteDatabase db = getWritableDatabase();
ContentValues values = new ContentValues();
values.put(KEY_NAME, contact.getName());
values.put(KEY_PHONE, contact.getPhone());
values.put(KEY_EMAIL, contact.getEmail());
values.put(KEY_ADDRESS, contact.getAddress());
values.put(KEY_IMAGEURI, contact.getImageURI().toString());
int rowsAffected = db.update(TABLE_CONTACTS, values, KEY_ID + "=?", new String[] { String.valueOf(contact.getId()) });
db.close();
return rowsAffected;
}
public List<Contact> getAllContacts() {
List<Contact> contacts = new ArrayList<Contact>();
SQLiteDatabase db = getWritableDatabase();
Cursor cursor = db.rawQuery("SELECT * FROM " + TABLE_CONTACTS, null);
if (cursor.moveToFirst()) {
do {
contacts.add(new Contact(Integer.parseInt(cursor.getString(0)), cursor.getString(1), cursor.getString(2), cursor.getString(3), cursor.getString(4), Uri.parse(cursor.getString(5))));
}
while (cursor.moveToNext());
}
cursor.close();
db.close();
return contacts;
}
}
EditActivity.class
package org.intracode.contactmanager;
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.text.TextWatcher;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;
public class EditContactActivity extends AppCompatActivity {
//live appearances in screen objects
EditText editName, editPhone, editEmail, editAddress;
Button editButton;
ImageView editImage;
Uri imageURI = Uri.parse("android.resource://org.intracode.contactmanager/drawable/no_logo.png");// including assigning
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_edit_contact);
//assigning fields
editName = (EditText) findViewById(R.id.editName);
editPhone = (EditText) findViewById(R.id.editPhone);
editEmail = (EditText) findViewById(R.id.editEmail);
editAddress = (EditText) findViewById(R.id.editAddress);
editButton = (Button) findViewById(R.id.editButton);
editImage = (ImageView) findViewById(R.id.editImage);
// getting passed arguments
String[] passedArg = getIntent().getStringArrayExtra("args");
editName.setText(passedArg[1]);
editPhone.setText(passedArg[2]);
editEmail.setText(passedArg[3]);
editAddress.setText(passedArg[4]);
editImage.setImageURI(Uri.parse(passedArg[5]));
//events
editName.addTextChangedListener(new TextWatcher() {
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
String email = charSequence.toString().trim();
editButton.setEnabled(String.valueOf(editName.getText()).trim().length() > 0 && MainActivity.isValidEmaillId(email));
}
@Override
public void afterTextChanged(Editable editable) {
}
});
// email event
editEmail.addTextChangedListener(new TextWatcher() {
String emailString = editEmail.getText().toString().trim();
@Override
public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {
}
@Override
public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
String email = charSequence.toString().trim();
editButton.setEnabled(editName.getText().toString().trim().length() > 0 && MainActivity.isValidEmaillId(email));
}
@Override
public void afterTextChanged(Editable editable) {
}
});
//buttonEvent
editButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent returnIntent = new Intent();
String[] passedArg = getIntent().getStringArrayExtra("args");
String[] argToReturn = {passedArg[0], String.valueOf(editName.getText()), String.valueOf(editPhone.getText()), String.valueOf(editEmail.getText()),
String.valueOf(editAddress.getText()), String.valueOf(editImage)};
returnIntent.putExtra("result", argToReturn);
setResult(Activity.RESULT_OK, returnIntent);
finish();
}
});
editImage.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {// defining a chooser
Intent intent = new Intent();// intent is an object that passes a messeges in our system
intent.setType("image/*");// Set an explicit MIME data type.
intent.setAction(intent.ACTION_GET_CONTENT);//Allow the user to select a particular kind of data and return it.
startActivityForResult(Intent.createChooser(intent, "Select Contact Image"), 1);
}
});
}
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
switch (requestCode) {
case 1:// comeback from image collecting screen
imageURI = data.getData();
editImage.setImageURI(data.getData());//Sets the content of this ImageView to the specified Uri.
}
}
}
}
联系班级
package org.intracode.contactmanager;
import android.net.Uri;
import java.net.URI;
/**
* Created by Roey on 09/08/2017.
*/
public class Contact {
private String name ,email, phone, address;
private Uri imageURI;
private int id;// added for database manners
public Contact(int id,String name ,String phone,String email,String address,Uri imageURI){
this.id=id;
this.name=name;
this.email=email;
this.phone=phone;
this.address=address;
this.imageURI=imageURI;
}
//getters
public String getName(){
return name;
}
public String getEmail(){
return email;
}
public String getPhone(){
return phone;
}
public String getAddress(){
return address;
}
public Uri getImageURI(){
return imageURI;
}
public int getId(){
return id;
}
//setters
public void setAll(String name,String phone,String email,String address,Uri imageURI){
this.name=name;
this.email=email;
this.phone=phone;
this.address=address;
this.imageURI=imageURI;
}
}