Android开发工程师文集-提示框，菜单，数据存储，组件篇

傷城~ 2021-09-15 12:16 280阅读 0赞

## 提示框，菜单，数据存储，组件篇 ##

## Toast ##

> Toast.makeText(context, text, 时间).show();

setDuration();//设置时间  
setGravity();//位置

获取：

添加toast.getView();  
imageView添加到toast中，addView();

LayoutInflater inflater = LayoutInflater.from(this); View toast_view=inflater.inflate(R.id.,null); Toast. Toast.setView(toast_view);

## AlertDialog ##

AlertDialog.Builder

setTitle();
    setIcon();
    setView();
    setItems();
    
    setMultiChoiceItems(); 复选
    setSingleChoiceItems(); 单选
    setNeutralButton();
    
    setPositiveButton();
    setNegativeButton();

AlertDialog dialog = builder.create(); .show();
    
    消失
    dialog.dismiss();

Notification通知栏，如接收短信

属性 Notification setTicker();//手机状态栏的提示 setWhen();//设置时间 setContentTitle(); setContentText(); setContentIntent(); Notification notification = builder.build();

## OptionsMenu ##

onCreateOptionsMenu(); 动态：menu.add(); 监听：onOptionsItemSelected();

public boolean onCreateOptionsMenu(Menu menu){ getMenuInflater().inflate(R.menu.main,menu); return true; }

监听：onOptionsItemSelected

public boolean onOptionsItemSelected(MenuItem item){ switch(item.getItemId()){ case R.id..: ... } }

## ContextMenu上下文菜单 ##

public boolean onCreateItemSelected(MenuItem item){ } public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo){ super.onCreateContextMenu(menu, v, menuIfo); }

## SubMenu 子菜单 ##

protected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } public boolean onCreateOptionsMenu(Menu menu){ getMenuInflater().inflate(R.menu.main, menu); return true; //return super.onOptionsItemSelected(item); }

xml

MenuInflater inflater = getMenuInflater();
    inflater.inflate(R.menu.main, menu);

## 数据存储方式 ##

四种：

1.  SharedPreferences
2.  SQLite
3.  Content Provider
4.  File

SharedPreferences是一种比较轻型的数据存储，基于xml的键值对存储，存储一些简单的信息。

SharedPreferences只能获取数据不能存储和修改，但能通过Editor实现存储修改。

步骤：

1.  获取SharedPreferences对象
2.  SharedPreferences.Editor
3.  Editor的putXXX的方法
4.  Editor.commit()

SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(MainActivity.this);

SharedPreferences sharedPreferences = getSharedPreferences("sharedPreferences", MODE_PRIVATE);
    Editor editor = sharedPreferences.edit();
    editor.putXXX();
    editor.commit();

用户名和密码的存储

sharedPreferences = getSharedPreferences("UserInfo", MODE_PRIVATE);
    Editor editor = sharedPreferences.editor();

SQLite的形式，以单个文件的存储，存储2T内存，以B-Tree形式。

SQLite的数据类型，null,integer,real,text,blob。

1.  SQLiteDatabase
2.  SQLiteOpenHelper

SQLiteDatabase db = openOrCreateDatabase("table.db", MODE_PRIVATE, null);

SQLiteOpenHelper

DBOpenHelper helper = new DBOpenHelper(MainActivity.this, "user.db"); SQLiteDatabase db = helper.getWritableDatabase(); Cursor c = db.rawQuery("select * from user", null);

public DBOpenHelper(Context context, String name, CursorFactory factory, int version){ super(context, name, factory, version); } public void onCreate(SQLiteDatabase db){ } public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion){ }

File file = this.getFilesDir(); File file = this.getCacheDir();//重要文件就不要放在这里

MODE\_PRIVATE

默认操作

MODE\_APPEND

文件是否存在

public void WriteFiles(String content){ try{ FileOutputStream fileOutputStream = openFileOutput("super.txt", MODE_PRIVATE); fileOutputStream.write(content.getBytes()); fileOutputStream.close(); }catch(){ }catch(){ } }

ContentProvider

public class MyContentProvider extends ContentProvider{ public int delete(Uri uri,String selection, String[] selectionArgs){ } }

Uri 通用资源标志符

Broadcast广播

BroadcastReceiver 广播接收器

使用：需要Intent对象，sendBroadcast(),sendOrderBroadcast(),sendStickyBroadcast()。

Service

public void onClick(View v){ switch(v.getId()){ case R.id.: Intent intent = new Intent(MainActivity.this, MyService.class); startService(intent); break; } }

public class MyService extends Service{ public void onCreate(){ super.onCreate(); } public int onStartCommand(Intent intent,int flags,int startId){ return super.onStartCommand(intent,flags,startId); } public void onDestroy(){ super.onDestroy(); } public IBinder onBind(Intent intent){ return null; } }

Bind

public void onCreate(){ } public IBinder onBind(Intent intent){ } public void unbindService(ServiceConnection conn){ }

ServiceConnection conn = new ServiceConnection(){ public void onServiceDisconnected(ComponentName name){ } public void onServiceConnected(ComponentName name, IBinder binder){ } }

系统服务

MountService,ClipboardService,getSystemService().

public Object getSystemService(String name){ }

POWER\_SERVICE,PowerManger电源服务  
ALARM\_SERVICE,AlarmManager闹钟服务

LayoutInflater inflater = MainActivity.this.getSystemService(LAYOUT_INFLATER_SERVICE); View view = inflater.inflate(R.layout. , null); setContentView(view);

getSystemService

GestureDetector

MotionEvent,GestureDetector,onGestureListener.

GestureOverlayView

Android:eventsInterceptionEnabled Android:fadeDuration Android:fadeEnabled Android:gestureColor

<android.gesture.GestureOverlayView android:id="" android:layout_width="" android:layout_height=""> <ImageView android:id="" android:layout_width="" android:layout_height="" </android.gesture.GestureOverlayView>

定位：分享 Android&Java 知识点  
完结！