基於SQLite的通信錄

文章目錄

基於SQLite的通信錄

實驗問題

實驗目的

掌握SQLiteOpenHelper類結構
掌握基於SQLite數據庫的應用開發過程
掌握ContentProvider發佈數據的方法
掌握ContentResolver獲取數據的方法

知識點回顧

Android系統中集成了SQLite數據庫，並且爲數據庫的操作提供了相關的類和方法，便於沒有數據庫開發經驗的開發者編寫程序。另外，Android平臺中得用ContentProvider機制來實現跨應用程序數據共享。一個應用程序可以通過ContentProvider來發布自己的數據，其他的應用程序可以通過ContentResolver來獲取共享數據。

實驗內容與步驟

1. 實現基於SQLite數據庫通信錄應用

運行結果視頻所示。通過單擊增加圖標打開添加通信錄界面，通過單擊通信錄中的各條信息可刪除選中項。

【步驟】
(1) 建立數據庫操作類DatabaseHelper，參考代碼如下：

public class DatabaseHelper extends SQLiteOpenHelper {
    private static final String DB_NAME="MyRelation.db";
    private static final String TABLE_NAME="relation";
    private static final String CREATE_TABLE="create table relation(" +
            "_id integer primary key autoincrement,name text,tel text,groupName text)";
    private SQLiteDatabase db;
    public DatabaseHelper(Context context)
    {
        super(context,DB_NAME,null,2);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        this.db=db;
        db.execSQL(CREATE_TABLE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {}
    public void insert(ContentValues values){
     SQLiteDatabase db=getWritableDatabase();
        db.insert(TABLE_NAME,null,values);
        db.close();
    }
    public void del(int id){
        if(null==db)
            db=getWritableDatabase();
        db.delete(TABLE_NAME,"_id=?",new String[]{String.valueOf(id)});
    }
    public Cursor query(){
        SQLiteDatabase db=getWritableDatabase();
        Cursor cursor=db.query(TABLE_NAME,null,null,null,null,null,null);
        return cursor;
    }
    public void close()
    {
        if(db!=null)
            db.close();
    }

}

(2) 創建主佈局，參考步驟如下：
① 使用約束佈局
② 添加文本框，並顯示“通信錄”，id爲title
③ 添加列表框，並能選擇“同學”、“同事”和“朋友”,id爲listView
④ 添加圖片按鈕組件，並設置響應方法爲“myClick”

(3) 修改主Activity文件MainActivity.java,參考代碼如下：

public class MainActivity extends AppCompatActivity {
private ListView listView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        listView=(ListView)findViewById(R.id.listView);
        getRelationFromDB();
    }
    private void getRelationFromDB()
    {
        final DatabaseHelper dbHelper=new DatabaseHelper(this);
        Cursor cursor=dbHelper.query();
        String[] from={"_id","name","tel","groupName"};
        int[] to={R.id._id, R.id.name, R.id.tel, R.id.group};
        SimpleCursorAdapter scadapter=new SimpleCursorAdapter(this,R.layout.relationlist,cursor,from,to);
        listView.setAdapter(scadapter);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener(){
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                final long temp=id;
                Log.d("temp", "onItemClick: ");
                AlertDialog.Builder adBuilder=new AlertDialog.Builder(MainActivity.this);
                adBuilder.setMessage("確認要刪除記錄嗎？").setPositiveButton("確認",new DialogInterface.OnClickListener(){
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dbHelper.del((int)temp);
                        Cursor cursor=dbHelper.query();
                        String[] from={"_id","name","tel","groupName"};
                        int[] to={R.id._id,R.id.name,R.id.tel,R.id.group};
                        SimpleCursorAdapter scadapter=new SimpleCursorAdapter(getApplicationContext(),R.layout.relationlist,cursor,from,to);
                        MainActivity.this.listView.setAdapter(scadapter);
                    }
                }).setNegativeButton("取消",new DialogInterface.OnClickListener(){

                    @Override
                    public void onClick(DialogInterface dialog, int which) {}
                });
                AlertDialog aleraDialog=adBuilder.create();
                aleraDialog.show();
            }
        });
        dbHelper.close();
    }
    public void myClick(View view)
    {
        Intent intent=new Intent(MainActivity.this,AddRelationActivity.class);
        startActivityForResult(intent,0x111);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(requestCode==0x111&&resultCode==0x111)
            getRelationFromDB();
    }
}

(4) 創建列表視圖佈局文件relationlist.xml,參考步驟如下：
① 使用水平線性佈局管理器
② 添加id文本框，id爲_id，設置爲不顯示
③ 添加姓名文本框，id爲name
④ 添加電話文本框，id爲tel
⑤ 添加聯繫人羣組文本框，id爲group

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal" android:layout_width="match_parent"
    android:descendantFocusability="blocksDescendants"
    android:layout_height="match_parent">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/_id"
        android:text="id "
        android:visibility="gone"
        android:textSize="20sp"/>
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/name"
        android:text="name"
        android:textSize="20sp"
        android:layout_weight="1"/>
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/tel"
        android:text="tel"
        android:textSize="20sp"
        android:layout_weight="1"/>
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/group"
        android:text="group"
        android:textSize="20sp" />
    <CheckBox
        android:id="@+id/select"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:clickable="false"
        android:visibility="gone"/>
</LinearLayout>

(5) 創建增加聯繫人界面佈局文件addrelation.xml，參考步驟如下：
① 使用豎直線性佈局
② 添加輸入姓名提示文本框
③ 添加姓名文本輸入框，id爲addName
④ 添加電話輸入提示文本框
⑤ 添加電話輸入框，id爲addTel
⑥ 添加羣組選擇提示框
⑦ 添加羣組選擇下拉列表框，id爲addGroup
⑧ 添加保存按鈕，設置單擊響應函數名爲：save

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical" android:layout_width="match_parent"
    android:layout_height="match_parent">
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="姓名"
        android:textSize="20sp"/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/addName"
        android:text="輸入姓名"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="電話"
        android:textSize="20sp"/>
    <EditText
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/addTel"
        android:text="輸入電話號碼"/>
    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="羣組"
        android:textSize="20sp"/>
    <Spinner
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:id="@+id/addGroup"
        android:entries="@array/array_group" />
    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:onClick="save"
        android:text="保存" />
</LinearLayout>

(6) 創建增加聯繫人界面Activity文件AddRelationActivity.java，參考代碼如下：

public class AddRelationActivity extends Activity {
    private EditText addName,addTel;
    private Spinner addGroup;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.addrelation);
        addName=(EditText) findViewById(R.id.addName);
        addTel=(EditText) findViewById(R.id.addTel);
        addGroup=(Spinner) findViewById(R.id.addGroup);
    }
    public void save(View view)
    {
        final ContentValues values=new ContentValues();
        values.put("name",addName.getText().toString());
        values.put("tel",addTel.getText().toString());
        values.put("groupName",addGroup.getSelectedItem().toString());
        final DatabaseHelper dbHelper=new DatabaseHelper(getApplicationContext());
        final AlertDialog.Builder adBuilder=new AlertDialog.Builder(this);
        adBuilder.setMessage("確認保存記錄嗎？").setPositiveButton("確認",new DialogInterface.OnClickListener(){
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dbHelper.insert(values);
                Intent intent=getIntent();
                setResult(0x111,intent);
                AddRelationActivity.this.finish();
            }
        }).setNegativeButton("取消", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {}
        });
        AlertDialog aleraDialog=adBuilder.create();
        aleraDialog.show();
    }
}

(7) 在AndroidManifest.xml文件中添加AddRelationActivity界面應用

<activity android:name=".AddRelationActivity"
    android:label="@string/app_name">
</activity>

2. 增加批量刪除功能。

實現ListView單擊和多選操作，在參考代碼基礎上新建ItemBean類，MyAdapter類。ItemBean用於保存聯繫人信息以及在多選中是否選中狀態和是否展示覆選框，MyAdapter適配器類用於對頁面內容處理。
重寫onItemClick和onItemLongClick方法，處理ListView不同的模式。

ItemBean.java

public class ItemBean {
    private String id;
    private String name;
    private String telphone;
    private String group;
    private boolean isSelect;
    private boolean isShowCheckBox;

    public boolean isShowCheckBox() {
        return isShowCheckBox;
    }
    public void setIsShowCheckBox(boolean isShowCheckBox) {
        this.isShowCheckBox = isShowCheckBox;
    }
    public ItemBean(String id,String name,String tellphone,String group,boolean isSelect,boolean isShowCheckBox ){
        this.id = id;
        this.name = name;
        this.telphone = tellphone;
        this.group = group;
        this.isSelect = isSelect;
    }
    public String getId() {
        return id;
    }
    public void setId(String id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getTelphone() {
        return telphone;
    }
    public void setTelphone(String telphone) {
        this.telphone = telphone;
    }
    public String getGroup() {
        return group;
    }
    public void setGroup(String group) {
        this.group = group;
    }
    public boolean isSelect() {
        return isSelect;
    }
    public void setIsSelect(boolean select) {
        isSelect = select;
    }
}

MyAdapter.java

public class MyAdapter extends BaseAdapter {
    private List<ItemBean> list;
    private LayoutInflater layoutInflater;

    public MyAdapter(Context context, List<ItemBean> list){
        this.list = list;
        layoutInflater = LayoutInflater.from(context);
    }
    @Override
    public int getCount() {
        return list.size();
    }

    @Override
    public Object getItem(int position) {
        return list.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        if(convertView == null){
            convertView = layoutInflater.inflate(R.layout.relationlist,null);
            ViewHolder viewHolder = new ViewHolder(convertView);
            convertView.setTag(viewHolder);
        }
        ViewHolder viewHolder = (ViewHolder) convertView.getTag();
        viewHolder.id.setText(list.get(position).getId());
        viewHolder.name.setText(list.get(position).getName());
        viewHolder.tel.setText(list.get(position).getTelphone());
        viewHolder.group.setText(list.get(position).getGroup());
        if(list.get(position).isShowCheckBox()){
            viewHolder.checkBox.setVisibility(View.VISIBLE);
            if(list.get(position).isSelect()){
                viewHolder.checkBox.setChecked(true);
            }else{
                viewHolder.checkBox.setChecked(false);
            }
        }else{
            viewHolder.checkBox.setVisibility(View.INVISIBLE);
        }
        return convertView;
    }
    public class ViewHolder {
        public final TextView id;
        public final TextView name;
        public final TextView tel;
        public final TextView group;
        public final CheckBox checkBox;
        public final View root;
        public ViewHolder(View root) {
            id = (TextView) root.findViewById(R.id._id);
            name = (TextView) root.findViewById(R.id.name);
            tel = (TextView) root.findViewById(R.id.tel);
            group = (TextView) root.findViewById(R.id.group);
            checkBox = (CheckBox) root.findViewById(R.id.select);
            this.root = root;
        }
    }
}

MainActivity.java

public class MainActivity extends AppCompatActivity implements View.OnClickListener, AdapterView.OnItemClickListener, AdapterView.OnItemLongClickListener {
    private ListView listView;
    private Boolean Flag = false;
    private LinearLayout editbar;//按鈕佈局
    private Button sure,cancel; //cancel是全選多選切換
    private MyAdapter adapter;
    private List<ItemBean> list;
    private Boolean isLineaLayoutVisible = false;//標記按鈕佈局的顯示
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        listView=(ListView)findViewById(R.id.listView);
        editbar = (LinearLayout)findViewById(R.id.edit_bar);
        sure = (Button)findViewById(R.id.delete);
        cancel = (Button)findViewById(R.id.cancel);
        sure.setOnClickListener(this);
        cancel.setOnClickListener(this);
        list = new ArrayList<ItemBean>();
        getFromDB_bean();
    }

    private void getFromDB_bean() {
        if(list != null) {
            list.clear();
        }
        final DatabaseHelper dbHelper=new DatabaseHelper(this);
        Cursor cursor=dbHelper.query();
        for (cursor.moveToFirst(); !cursor.isAfterLast(); cursor.moveToNext()) {
            String ids = cursor.getString(cursor.getColumnIndex("_id"));
            String names = cursor.getString(cursor.getColumnIndex("name"));
            String tels = cursor.getString(cursor.getColumnIndex("tel"));
            String groups = cursor.getString(cursor.getColumnIndex("groupName"));
            list.add(new ItemBean(ids,names,tels,groups,false,false));
        }
        adapter = new MyAdapter(this,list);
        listView.setAdapter(adapter);
        listView.setOnItemClickListener(this);
        listView.setOnItemLongClickListener(this);
        dbHelper.close();
    }

    //這一段沒什麼用了，但是onActivityResult（）用到
    private void getRelationFromDB()
    {
        final DatabaseHelper dbHelper=new DatabaseHelper(this);
        Cursor cursor=dbHelper.query();
        String[] from={"_id","name","tel","groupName"};
        int[] to={R.id._id, R.id.name, R.id.tel, R.id.group};
        SimpleCursorAdapter scadapter=new SimpleCursorAdapter(this,R.layout.relationlist,cursor,from,to);
        listView.setAdapter(scadapter);
        listView.setOnItemClickListener(new AdapterView.OnItemClickListener(){
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
                final long temp=id;
                Log.d("temp", "onItemClick: ");
                AlertDialog.Builder adBuilder=new AlertDialog.Builder(MainActivity.this);
                adBuilder.setMessage("確認要刪除記錄嗎？").setPositiveButton("確認",new DialogInterface.OnClickListener(){
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        dbHelper.del((int)temp);
                        Cursor cursor=dbHelper.query();
                        String[] from={"_id","name","tel","groupName"};
                        int[] to={R.id._id,R.id.name,R.id.tel,R.id.group};
                        SimpleCursorAdapter scadapter=new SimpleCursorAdapter(getApplicationContext(),R.layout.relationlist,cursor,from,to);
                        MainActivity.this.listView.setAdapter(scadapter);
                    }
                }).setNegativeButton("取消",new DialogInterface.OnClickListener(){

                    @Override
                    public void onClick(DialogInterface dialog, int which) {}
                });
                AlertDialog aleraDialog=adBuilder.create();
                aleraDialog.show();
            }
        });
        dbHelper.close();
    }
    public void myClick(View view)
    {
        Intent intent=new Intent(MainActivity.this,AddRelationActivity.class);
        startActivityForResult(intent,0x111);
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(requestCode==0x111&&resultCode==0x111)
            getRelationFromDB();
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.delete:
                String str = "";
                for(ItemBean itemBean : list){
                    if(itemBean.isSelect()){
                        str+=itemBean.getName()+itemBean.getName()+"\n";
                        delete_one(itemBean);
                    }
                }
                if(str.equals("")){
                    Toast.makeText(this,"您沒有選擇",Toast.LENGTH_SHORT).show();

                }else{
                    Toast.makeText(this,str,Toast.LENGTH_SHORT).show();
                }
                break;
            case R.id.cancel:
                if(cancel.getText().equals("選擇全部")){
                    for(ItemBean itemBean : list){
                        itemBean.setIsSelect(true);
                    }
                    cancel.setText("取消全部");
                }else{
                    for(ItemBean itemBean : list){
                        itemBean.setIsSelect(false);
                    }
                    cancel.setText("選擇全部");
                }
                adapter.notifyDataSetChanged();
                break;
        }
    }

    @Override
    public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
        if(isLineaLayoutVisible){//當按鈕佈局顯示時候纔有權多項選擇
            list.get(position).setIsSelect(!list.get(position).isSelect());//向表中記錄被選擇的item
            adapter.notifyDataSetChanged();//更新ListView
        }
        else{
            ItemBean item = list.get(position);
            delete_one(item);
        }
    }

    @Override
    public boolean onItemLongClick(AdapterView<?> parent, View view, int position, long id) {
        try {
            list.get(position).setIsSelect(true);//記錄選擇的item有機率不成功，我也不知道爲啥，所以就用try
        } catch (Exception e) {
            e.printStackTrace();
            list.get(position).setIsSelect(true);
        }
        for(ItemBean itemBean : list){
            itemBean.setIsShowCheckBox(true);//將所有的Item的CheckBox設置爲選擇狀態
        }
        adapter.notifyDataSetChanged();
        editbar.setVisibility(View.VISIBLE);//長按item設置按鈕佈局爲顯示狀態
        isLineaLayoutVisible = true;
        return true;
    }
    @Override
    public void onBackPressed() {
        if (isLineaLayoutVisible){
            editbar.setVisibility(View.INVISIBLE);
            isLineaLayoutVisible = false;
            for(ItemBean itemBean : list){//按返回鍵時取消所有選擇記錄，同是吧按鈕佈局設置爲不可見
                itemBean.setIsShowCheckBox(false);
                itemBean.setIsSelect(false);
            }
            adapter.notifyDataSetChanged();
        }else {
            super.onBackPressed();
        }
    }
    public void delete_one(ItemBean item){
        final DatabaseHelper dbHelper=new DatabaseHelper(this);
        Cursor cursor=dbHelper.query();
        //Toast.makeText(this,list.get(position).getName()+list.get(position).getTelphone(),Toast.LENGTH_SHORT).show();
        final String temp=item.getId();
        Log.d("temp", "onItemClick: ");
        AlertDialog.Builder adBuilder=new AlertDialog.Builder(MainActivity.this);
        adBuilder.setMessage("確認要刪除記錄嗎？").setPositiveButton("確認",new DialogInterface.OnClickListener(){
            @Override
            public void onClick(DialogInterface dialog, int which) {
                dbHelper.del(Integer.parseInt(temp));
                getFromDB_bean();
            }
        }).setNegativeButton("取消",new DialogInterface.OnClickListener(){

            @Override
            public void onClick(DialogInterface dialog, int which) {}
        });
        AlertDialog aleraDialog=adBuilder.create();
        aleraDialog.show();
        dbHelper.close();
    }
}

實驗問題

主要在參考代碼基礎上實現了ListView多選。
代碼中仍然存在Bug，例如單擊刪除後再多選，出錯；多選後再添加，出錯。後續修改

【Android實驗】基於SQLite的通信錄

基於SQLite的通信錄

文章目錄

實驗目的

知識點回顧

實驗內容與步驟

1. 實現基於SQLite數據庫通信錄應用

2. 增加批量刪除功能。

實驗問題

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https://yachay.unat.edu.pe/blog/index.php?comment_area=format_blog&comment_component=blog&comment_co

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