实验8 SQLite数据库操作

1.0" encoding="utf-8"?> <resources> <string name="app_name">contact</string> <string name="action_settings">Settings</string> <string name="hello_world">Hello world!</string> <string name="Name">姓名：</string> <string name="phone">固定电话：</string> <string name="mobile">移动电话：</string> <string name="email">电子邮件：</string> <string name="post">邮政编码：</string> <string name="addr">通信地址：</string> <string name="comp">公司名称：</string> <string name="add">添加</string> <string name="modify">修改</string> <string name="delete">删除</string> <string name="save">保存</string> <string name="message">确认删除此联系人吗？</string> <string name="ok">确定</string> <string name="cancel">取消</string> <string name="title">联系人列表</string> </resources>

MainActivity.java部分代码:

public class MainActivity extends Activity {

    private DBOpenHelper dbOpenHelper;
    private ContantsAdapter contantsAdapter;
    private ListView dbListView;
    private Cursor cursor;
    
    final int MENU_ADD = Menu.FIRST;
    final int MENU_CHANGE = Menu.FIRST+1;
    
    private List<String> ids;
    private List<String> names;
    private List<String> phones;
    AlertDialog dialog;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        dbOpenHelper = new DBOpenHelper(this);
        dbListView = (ListView)findViewById(R.id.db_listview);
        refreshDBOpenHelper();

        dbListView.setOnItemClickListener(new OnItemClickListener(){

            public void onItemClick(AdapterView<?> arg0, View arg1, int position,
                    long arg3) {
                Intent intent= new Intent();
                intent.putExtra("cmd", 0);    
                String contants_id = ids.get(position);//0代表查询联系人，1代表添加联系人
                intent.putExtra("id", contants_id);
                intent.setClass(MainActivity.this, DetailContantsActivity.class);
                startActivity(intent);
            }
        });
        
        dbListView.setOnItemLongClickListener(new OnItemLongClickListener(){

            public boolean onItemLongClick(AdapterView<?> arg0, View arg1,
                    final int position, long arg3) {
                dialog = new AlertDialog.Builder(MainActivity.this)
                .setTitle("提示!!")
                .setMessage("确定要删除这条记录？")
                .setPositiveButton("确定",
                 new DialogInterface.OnClickListener()
                 {
                     public void onClick(DialogInterface dialog, int whichButton)
                     {
                         String contants_id = ids.get(position);
                         dbOpenHelper.deleteContants(contants_id);
                         dbOpenHelper.close();
                         Toast.makeText(MainActivity.this, "正在删除数据库，请稍后。。。", Toast.LENGTH_LONG).show();
                         refreshDBOpenHelper();
                         contantsAdapter.notifyDataSetChanged();
                     }
                     })
                 .setNegativeButton("取消",new DialogInterface.OnClickListener()
                 {
                      public void onClick(DialogInterface dialog, int whichButton)
                      {
                         dialog.dismiss();
                      }
                  }).show();
                return false;
            }
        });
    }
    
    @Override
    protected void onResume() {
        refreshDBOpenHelper();    
        contantsAdapter.notifyDataSetChanged();
        super.onResume();
    }

    public void refreshDBOpenHelper(){
        cursor = dbOpenHelper.selectContants();
        ids = new ArrayList<String>();
        names = new ArrayList<String>();
        phones = new ArrayList<String>();
        
        int count = cursor.getCount();
        if(count>0){
            for(int i=0;i<count;i++){
                cursor.moveToPosition(i);
                ids.add(cursor.getString(0));
                names.add(cursor.getString(1));
                phones.add(cursor.getString(2));
            }
        }else{
            Toast.makeText(this, R.string.not_dbcursor_values, Toast.LENGTH_SHORT).show();
        }
        contantsAdapter = new ContantsAdapter(this,names,phones);
        dbListView.setAdapter(contantsAdapter);
        cursor.close();
        dbOpenHelper.close();
    }
    
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        menu.add(0, MENU_ADD, 0, R.string.menu_add)
            .setIcon(R.drawable.add);    //add - add_button 
        menu.add(0, MENU_CHANGE, 0, R.string.menu_change)
            .setIcon(R.drawable.modify);        //add -add_change_password
        return super.onCreateOptionsMenu(menu);
    }
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch(item.getItemId()){        //
        case MENU_ADD:            //press change add button
            Intent add_intent= new Intent(this,DetailContantsActivity.class);
            add_intent.putExtra("cmd", 1);
            startActivity(add_intent);
            break;
        case MENU_CHANGE:    //press change password button
            Intent change_password_intent = new Intent(MainActivity.this,PasswordManage.class);
            startActivityForResult(change_password_intent,0);
            break;
        }
        return super.onOptionsItemSelected(item);
    }
}

【实验结果截图】

【实验小结】

    这次实验感觉很难，因为缺了几节课，什么都没学习到，但是请教了几位同学，勉强完成了一部分。

实验8 SQLite数据库操作

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