android小实例.docx

android小实例LoginActivity.java 类：package com.example.empandroid;import android.app.Activity;import android.app.ProgressDialog;import android.content.Intent;import android.database.Cursor;import android.os.Bundle;import android.text.Editable;import android.text.TextWatcher;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;public class LoginActivity extends Activity implements OnClickListenerEditText username,password;Button login,register,bt_username_clear,bt_pwd_clear;DBHelper helper = new DBHelper(this);ProgressDialog m_dlog ;private TextWatcher uname_watcher ;private TextWatcher pwd_watcher ;Overrideprotected void onCreate(Bundle savedInstanceState) super.onCreate(savedInstanceState);setContentView(R.layout.login_main);username = (EditText) findViewById(R.id.username);password = (EditText) findViewById(R.id.password);login = (Button) findViewById(R.id.login);register = (Button) findViewById(R.id.register);bt_username_clear = (Button) findViewById(R.id.bt_username_clear);bt_pwd_clear = (Button) findViewById(R.id.bt_pwd_clear);login.setOnClickListener(this);register.setOnClickListener(this);bt_username_clear.setOnClickListener(this);bt_pwd_clear.setOnClickListener(this);initWatcher();username.addTextChangedListener(uname_watcher);password.addTextChangedListener(pwd_watcher);public void initWatcher()uname_watcher = new TextWatcher() Overridepublic void onTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) Overridepublic void beforeTextChanged(CharSequence arg0, int arg1, int arg2,int arg3) Overridepublic void afterTextChanged(Editable s) if(s.toString().length()0)bt_username_clear.setVisibility(View.VISIBLE);elsebt_username_clear.setVisibility(View.INVISIBLE);pwd_watcher = new TextWatcher() Overridepublic void onTextChanged(CharSequence arg0, int arg1, int arg2, int arg3) Overridepublic void beforeTextChanged(CharSequence arg0, int arg1, int arg2,int arg3) Overridepublic void afterTextChanged(Editable s) if(s.toString().length()0)bt_pwd_clear.setVisibility(View.VISIBLE);elsebt_pwd_clear.setVisibility(View.INVISIBLE);Overridepublic void onClick(View v) switch (v.getId() case R.id.register:Intent intent = new Intent(LoginActivity.this, AddEmpActivity.class);String uname = username.getText().toString();intent.putExtra(uname, uname);startActivity(intent);break;case R.id.login:login();break;case R.id.bt_pwd_clear:password.setText();break;case R.id.bt_username_clear:username.setText();break;default:break;public void login()String uname = username.getText().toString();String pwd = password.getText().toString();System.out.println(name=+uname+=pwd=+pwd);Cursor cur = helper.getByUserName(userinfo, new Stringuser,code, user=? and code=?, new Stringuname,pwd);System.out.println(cur.getCount()=+cur.getCount();if(cur.getCount()0)m_dlog=ProgressDialog.show(LoginActivity.this, 请稍等,正在为你登录,true);Intent intent = new Intent(LoginActivity.this, MainActivity.class);intent.putExtra(uname, uname);startActivity(intent);elseToast.makeText(this, 登录失败！, 100).show();MainActivity.java 类：package com.example.empandroid;import android.app.AlertDialog;import android.app.AlertDialog.Builder;import android.content.DialogInterface;import android.content.Intent;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.os.Bundle;import android.support.v7.app.ActionBarActivity;import android.view.ContextMenu;import android.view.ContextMenu.ContextMenuInfo;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.view.View.OnClickListener;import android.widget.AdapterView;import android.widget.AdapterView.AdapterContextMenuInfo;import android.widget.Button;import android.widget.ListView;import android.widget.SimpleCursorAdapter;import android.widget.TextView;import android.widget.Toast;SuppressWarnings(all)public class MainActivity extends ActionBarActivity implements OnClickListenerprivate Button insert,select;private TextView show_name,show_user,show_code,show_phone,currUser,logout;private ListView lv;DBHelper dbhelper = new DBHelper(this);Cursor cursor;/EmpInfo emp;public Integer _id;SimpleCursorAdapter adapter;Overrideprotected void onCreate(Bundle savedInstanceState) super.onCreate(savedInstanceState);setContentView(com.example.empandroid.R.layout.activity_main);/初始化控件insert = (Button)findViewById(R.id.insert);select = (Button)findViewById(R.id.select);show_name = (TextView) findViewById(R.id.show_name);show_user = (TextView) findViewById(R.id.show_user);show_code = (TextView) findViewById(R.id.show_code);show_phone = (TextView) findViewById(R.id.show_phone);currUser = (TextView) findViewById(R.id.currUser);currUser.setText(getIntent().getStringExtra(uname);logout = (TextView) findViewById(R.id.logout);insert.setOnClickListener(this);select.setOnClickListener(this);logout.setOnClickListener(this);lv = (ListView) findViewById(R.id.lv);registerForContextMenu(lv);select();/更新Overridepublic void onClick(View v) switch (v.getId() case R.id.insert:Intent intent = new Intent(MainActivity.this, AddEmpActivity.class);startActivity(intent);break;case R.id.select:select();break;case R.id.logout:Intent logoutintent = new Intent(MainActivity.this,LoginActivity.class);startActivity(logoutintent);break;default:break;/显示数据在listview上public void select()SQLiteDatabase db = dbhelper.getWritableDatabase();dbhelper.onCreate(db);Cursor cur = dbhelper.query(userinfo);adapter = new SimpleCursorAdapter(MainActivity.this, R.layout.list_emp, cur, new Stringname,user,code,phone,new intR.id.show_name,R.id.show_user,R.id.show_code,R.id.show_phone);lv.setAdapter(adapter);adapter.notifyDataSetChanged();/长按菜单public void onCreateContextMenu(ContextMenu menu, View v,ContextMenuInfo menuInfo) menu.setHeaderTitle(快捷操作);menu.add(Menu.NONE, 1, 1, 删除);menu.add(Menu.NONE, 2, 2, 修改);super.onCreateContextMenu(menu, v, menuInfo);Overridepublic boolean onContextItemSelected(MenuItem item) /获取长按着弹出上下文菜单的LIstView点击的ID值AdapterView.AdapterContextMenuInfo menuInfo = (AdapterContextMenuInfo) item.getMenuInfo();final int id = (int) menuInfo.id;if(id = -1)super.onContextItemSelected(item);switch (item.getItemId() case 1:delete(menuInfo);break;case 2:update(menuInfo);break;default:break;return super.onContextItemSelected(item);/删除public void delete(AdapterView.AdapterContextMenuInfo menuInfo)Cursor cur = (Cursor) lv.getItemAtPosition(menuInfo.position);cur.moveToPosition(menuInfo.position);_id = cur.getInt(0);System.out.println(id=name=+_id+=+cur.getInt(1);Builder builder = new Builder(MainActivity.this);builder.setMessage(你确定要删除？);AlertDialog d = builder.create();d.setButton(是, new DialogInterface.OnClickListener() Overridepublic void onClick(DialogInterface dialog, int which) dbhelper.del(_id);select();/更新Toast.makeText(MainActivity.this, 删除成功, 1000).show(););d.setButton2(否, new DialogInterface.OnClickListener() Overridepublic void onClick(DialogInterface dialog, int which) dialog.cancel(););d.show();public void update(AdapterView.AdapterContextMenuInfo menuInfo)Intent intent = new Intent(MainActivity.this, UpdateEmpActivity.class);Cursor cur = (Cursor) lv.getItemAtPosition(menuInfo.position);cur.moveToPosition(menuInfo.position);_id = cur.getInt(0);System.out.println(id=name=+_id+=+cur.getInt(1);String name = cur.getString(cur.getColumnIndex(name);String user = cur.getString(cur.getColumnIndex(user);String code = cur.getString(cur.getColumnIndex(code);String phone = cur.getString(cur.getColumnIndex(phone);intent.putExtra(name, name);intent.putExtra(user, user);intent.putExtra(code, code);intent.putExtra(phone, phone);intent.putExtra(_id, _id);startActivity(intent);DBHelper.java 类package com.example.empandroid;import android.content.ContentValues;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;import android.database.sqlite.SQLiteOpenHelper;public class DBHelper extends SQLiteOpenHelperprivate static final String db_name = test.db;private static final int db_version = 1;private static final String table_name = userinfo;private static final String create_info = create table if not exists userinfo(+_id integer primary key autoincrement,name varchar(20),user varchar(20),+code varchar(20),phone number(11);private SQLiteDatabase db;public DBHelper(Context context) super(context, db_name, null, db_version);Overridepublic void onCreate(SQLiteDatabase db) this.db = db;db.execSQL(create_info);public void insert(ContentValues values,String tableName)if(db = null)db = getWritableDatabase();db.execSQL(create_info);db.insert(tableName, null, values);db.close();public void update(ContentValues values,String tableName,String id)db = getWritableDatabase();db.update(tableName, values, _id=?, id);Overridepublic void onUpgrade(SQLiteDatabase arg0, int arg1, int arg2) public void close()if(db != null)db.close();public Cursor query(String tableName)if(db = null)db = getWritableDatabase();Cursor c = db.query(tableName, null, null, null, null, null, null);return c;public Cursor getByUserName(String tableName,String columns,String selection,String selectionArgs)if(db = null)db = getWritableDatabase();Cursor c = db.query(true,tableName, columns, selection, selectionArgs, null, null, null, null);return c;public void del(int id)if(db = null)db = getWritableDatabase();db.delete(table_name,_id=?, new StringString.valueOf(id);AddEmpActivity.java类：package com.example.empandroid;import android.app.Activity;import android.content.ContentValues;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;public class AddEmpActivity extends Activity implements OnClickListenerprivate EditText name,user,code,phone;private Button save,clear;DBHelper helper = new DBHelper(this);MainActivity activity= new MainActivity();Overrideprotected void onCreate(Bundle savedInstanceState) super.onCreate(savedInstanceState);setContentView(R.layout.add_emp);name = (EditText) findViewById(R.);user = (EditText) findViewById(R.id.user);code = (EditText) findViewById(R.id.code);phone = (EditText) findViewById(R.id.phone);save = (Button) findViewById(R.id.saveButton);clear = (Button) findViewById(R.id.clearButton);save.setOnClickListener(this);clear.setOnClickListener(this);Overridepublic void onClick(View v) switch (v.getId() case R.id.saveButton:save();break;case R.id.clearButton:clear();break;default:break;public void save()String empname = name.getText().toString();String empuser = user.getText().toString();String empcode = code.getText().toString();String empphone = phone.getText().toString();if(empname.length()0&empuser.length()0&empcode.length()0&empphone.length()0)ContentValues values = new ContentValues();values.put(name, empname);values.put(user, empuser);values.put(code, empcode);values.put(phone, empphone);/需要创建表/TODO:helper.insert(values, userinfo);Toast.makeText(AddEmpActivity.this, 增加成功, 1000).show();Intent intent = new Intent(AddEmpActivity.this,MainActivity.class);String uname = getIntent().getStringExtra(uname);intent.putExtra(uname, uname);startActivity(intent);elseToast.makeText(AddEmpActivity.this, 增加失败, 1000).show();public void clear()name.setText();user.setText();code.setText();phone.setText(); UpdateEmpActivity.java 类：package com.example.empandroid;import android.app.Activity;import android.content.ContentValues;import android.content.Intent;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.EditText;import android.widget.Toast;public class UpdateEmpActivity extends Activity implements OnClickListenerprivate EditText name,user,code,phone;private Button save,clear;DBHelper helper = new DBHelper(this);private int _id;MainActivity activity= new MainActivity();Overrideprotected void onCreate(Bundle savedInstanceState) super.onCreate(savedInstanceState);setContentView(R.layout.upd_emp);name = (EditText) findViewById(R.);user = (EditText) findViewById(R.id.user);code = (EditText) findViewById(R.id.code);phone = (EditText) findViewById(R.id.phone);save = (Button) findViewById(R.id.saveButton);clear = (Button) findViewById(R.id.clear