Android之控件与布局，结构知识点，基础完结

以你之姓@ 2021-09-15 15:56 137阅读 0赞

![标题图][1240]

在Android中我们常常用到很多UI控件，如`TextView`，`EditText`，`ImageView`，`Button`，`ImageButton`，`ToggleButton`，`CheckBox`，`RadioButton`等等这些可以自己多用就会了。

也会学到一些布局如：`LinearLayout 线性布局`，`RelativeLayout 相对布局`，`FrameLayout 帧布局`，`AbsoluteLayout绝对布局`，`TableLayout 表格布局`，`GridLayout 网格布局`，`ConstraintLayout 约束布局`。

`LinearLayout 线性布局`:

android:orientation="vertical"
    android:orientation="horizontal"

`RelativeLayout 相对布局`：

android:layout_alignParentTop
    android:layout_alignParentBottom
    android:layout_alignParentLeft
    android:layout_alignParentRight

android:layout_marginTop
    android:layout_marginBottom
    android:layout_marginLeft
    android:layout_marginRight
    android:layout_margin

android:layout_centerVertical
    android:layout_centerHorizontal
    android:layout_centerInParent

android:layout_above
    android:layout_below
    android:layout_alignLeft
    android:layout_alignRight
    android:layout_toLeftOf
    android:layout_toRightOf
    android:layout_alignBottom
    android:layout_alignTop
    android:layout_alignBaseline

`TableLayout 表格布局`：

android:layout_span
    android:layout_column
    android:collapseColumns
    android:shrinkColumns
    android:stretchColumns

属性

android:id
    android:layout_width
    android:match_parent
    android:text
    android:background
    android:textSize
    android:textColor
    android:inputType
    android:hint

结构：

> AndroidManifest.xml为整个应用的主配置，清单文件，应用的包名、版本号、组件、权限等信息。

Activity的活动状态：

activity is running：为活动状态
    onResume()->running->onPause()：为暂停状态
    onStart()->onResume()->running->onPause()->onStop()：为停止状态
    onDestroy()：为非活动状态

onCreate() onStart() onResume() onPause() onStop() onDestroy() onRestart()

跳转：第二个界面：

private Button mButton;
    private String text="dashu";
    
    mButton.setOnClickListener(new View.OnClickListener(){
     @Override
     public void onClick(View v){
      Intent data = new Intent();
      data.putExtra("text",text);
      setResult(2,data);
      finish();
     }
    }

跳转：第一个界面：

@Override
    protected void onActivityResult(int requestCode,int resuleCode,Intent data){
     super.onActivityResult(requestCode,resultCode,data):
       if(requestCode==1&&resultCode==2){
          String text = data.getStringExtra("text");
          textView.setTextView(text);
        }
    }

ListView与ArrayAdapter的搭配：

//准备数据源->适配器加载数据源->控件加载适配器
    public class MainActivity extends AppCompatActivity{ 
     private ListView listView;
     private ArrayAdapter<String> list_adpater;
    
     @Override
     protected void onCreate(Bundle savedInsstanceState){
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);
      listView=findViewById(R.id.listView);
    
      //1
     String data[] = {
       "dashu1","dashu2","dashu3"};
     //2
      list_adpater = new ArrayAdapter<>(this,android.R.layout.simple_list_item_1,data);
     //3
      listView.setAdapter(list_adapter);
    
     }
    }

ListView与SimpleAdapter的搭配：

//列表项
    //布局
    <ListView
     android:id="@android:id/app_list"
     android:layout_width="match_parent"
     android:layout_height="wrap_content"/>
    //单个列表项
    <ImageView
            android:id="@+id/icon_image_view"
            android:layout_width="60dp"
            android:layout_height="60dp"
            android:src="@mipmap/ic_launcher"/>
    <TextView
            android:id="@+id/title_text_view"
            android:layout_width="match_parent"
            android:layout_height="60dp"
            android:text="@string/app_name"
            android:textSize="24sp"/>

private ListView listView;
    private List<Map<String,Object>> dataList;
    private SimpleAdapter simple_adapter;
    //1.
    dataList = new ArrayList<>();
    dataList=getData();
    private List<Map<String,Object>> getData(){
     for(int i = 0;i<10;i++){
       Map<String,Object> map = new HashMap<>();
       map.put("image",R.drawable.images1);
       map.put("text",i);
       dataList.add(map);
     }
      return dataList;
    }
    //2.
    simple_adapter = new SimpleAdapter(this,dataList,R.layout.item,new String[]{
       "image","text"},new int[]{
       "R.id.imageView","R.id.imageView"});
    //3.
    listView.setAdapter(simple_adapter);

To:

public class App{
     private String appName;
     private int appId;
      App(String appName,int appId){
     }
    }
    //
    public class AppAdapter extentds ArrayAdapter<App>{
        ...
         App app = getItem(position);
         View view = LayoutInflater.from(getContext()).inflate(...);
    }
    //
     //获取视图
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            //创建ViewHolder
            ViewHolder viewHolder = null;
            //如果为空
            if (convertView == null){
             //mInflater.inflate(渲染布局，parent , false)
             convertView = mInflater.inflate(R.layout.item_msg,parent,false);
             viewHolder = new ViewHolder();//创建类对象
             //视图
             viewHolder.mIvImg = convertView.findViewById(R.id.id_iv_img);
             viewHolder.mTvTitle = convertView.findViewById(R.id.id_tv_title);
             viewHolder.mTvContent = convertView.findViewById(R.id.id_tv_content);
    
             convertView.setTag(viewHolder);// convertView.getTag();
    
            }else {
                viewHolder = (ViewHolder) convertView.getTag();// convertView.getTag();
            }
            //获取数据位置
            Message msg = mDatas.get(position);//数据集合 private List<Message> mDatas;
            viewHolder.mIvImg.setImageResource(msg.getImgResId());//获取图片位置
            viewHolder.mTvTitle.setText(msg.getTitle());//获取标题
            viewHolder.mTvContent.setText(msg.getContent());//获取内容
    
            return convertView;
        }
    
        public static class ViewHolder{
            //静态内部类，类调用
            ImageView mIvImg;
            TextView mTvTitle;
            TextView mTvContent;
        }
    //or
    App app = getItem(position);
    if(convertView==null){
              view=LayoutInflater.from(getContext()).inflate(resourceId, null);
              viewHolder=new ViewHolder();
              viewHolder.imageView= view.findViewById(R.id.app_image);
              viewHolder.textView= view.findViewById(R.id.appl_name);
              view.setTag(viewHolder);
        }else{
             view=convertView;
             viewHolder = (ViewHolder) view.getTag();
      ...
      return view;
    }

To:

private List<Map<String,Object>> dataList;
    private SimpleAdapter simpleAdapter;
    private void getData(){
     for(int i=0;i<##;i++){ 
      Map<String,Object> map = new HashMap<>();
      map.put("",##);
      dataList.add(##);
     }
    }

`ProgressBar`：`max，progress，secondaryProgress`

style="?android:attr/progressBarStyleHorizontal"
    style="?android:attr/progressBarStyleLarge"
    style="?android:attr/progressBarStyle"
    style="?android:attr/progressBarStyleSamll"

int first=progressBar.getProgress();
    int second=progressBar.getSecondaryProgress();
    int max = progress.getMax();

progressBar.incrementProgressBy(5);
    progressBar.incrementSecondaryProgressBy(5);
    
    progress.incrementProgressBy(-5);
    progressBar.incrementSecondaryProgressBy(-5);

ProgressDialog progressDialog = new ProgressDialog(this);
    //
    progressDialog.setProgresssStyle(ProgressDialog.STYLE_HORIZONTAL);
    progressDialog.setTitle("");
    progressDialog.setIcon("");
    //
    progressDialog.setMax(100);
    progressDialog.incrementProgressBy(20);
    //
    progessDialog.setButton(DialogInterface.BUTTON_POSITIVE,"确定",new DialogInterface.OnClickListener(){
      ...
    });
    progressDialog.setCancelable(true);
    //
    progressDialog.show();

`SeekBar`：`OnSeekBarChangeListener`

<SeekBar>
      ...
      android:max="100"
      android:progress="40"
    </SeekBar>

seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener(){
    
    });

日历选择器：`OnDateChangedListener`

//DataPicker日历选择器
    private DataPicker dataPicker;
    private Calendar calendar;
    private int year,day,hour,minute;
    //
    calendar = Calendar.getInstance();
    //
    year = calendar.get(Calendar.YEAR);
    ...
    minute = calendar.get(Calendar.MINUTE);
    
    //DataPickerDialog-OnDateSetListener()
    new DatePickerDialog(this, newDatePickerDialog.OnDateSetListener(){
      ...
    },year,calendar.get(Calendar.MONTH),day).show();
    //TimePicker-setOnTimeChangedListener()
    //TimePickerDialog-OnTimeSetListener
    new TimePickerDialog(this, new TimePickerDialog.OnTimeSetListener(){
      ....
    },hour,minute,true).show();

`Meau`：

//OptionsMenu,SubMenu,ContextMenu
    //
    <menu>
    <item android:id="@+id/item1"
    android:title="1"
    </item>
    <item android:id="@+id/item12"
    android:title="12"
    </item>
    //
    <item android:id="@+id/play" android:title="玩">
     <menu>
      <item android:id="" android:title="下棋"/>
      <item .../>
     </menu>
    </item>
    //
    雷同SubMenu
    //
    getMenuInflater().inflate();
    onCreateOptionsMenu();
    onCreateContextMenu();
    //动态
    onCreateOptionsMenu(Menu menu){
     menu.add(1,1,1,"1");
     menu.add(1,2,1,"2");
      return super.onCreateOptionsMenu(menu);
    }
    onCreateContextMenu(ContextMenu menu,View v,ContextMenu.ContextMenuInfo menuInfo){
     //menu.setHeaderTitle();
     //menu.setHeaderIcon();
     menu.add(1,1,1,"1");
     menu.add(1,2,1,"2");
      ...
      super.onCreateContextMenu(menu,v,menuInfo);
    }
    //
    onCreateOptionsMenu(Menu menu){
     //SubMenu play=menu.addSubMenu();
     play.setHeaderTitle();
     play.setHeaderIcon();
     play.add();
     play.add();
      SubMenu play2=menu.addSubMenu();
      paly2.add(2,1,1,"");
      play2.add(2,2,1,"");
      return super.onCreateOptionsMenu(menu);
    }
    //
    ContextMenu
    ListView = findViewById(R.id.listView);
    adapter = new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,data);
    listView.setAdapter(adapter);
    registerForContextMenu(listView);
    
    //OnOptionsItemSelected
    OnOptionsItemSelected(MenuItem item){
     if(item.getGroupId() == 1){
      switch(item.getItemId()){
       case 1:
         break;
       case 2:
        break;
      }
     }
     ...
    }

`Notification 通知`：

图标（SmallIcon）
    标题（ContextTitle）
    内容（ContextText）
    时间（When）

NotificationCompat.Builder builder = new NotificationCompat.Builder(this);
    //
    builder.setSmallIcon();
    ...
    builder.setDefaults(Notification.DEFAULT_ALL);
    //
    PendingIntent类-setContentIntent()
    NotificationManager去完成发送和取消通知的事情

`Dialog 对话框`：

//setPositiveButton()和setNegativeButton()：添加确定和取消按钮
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle();
    ...
    builder.setPositiveButton("确认", new DialogInterface.OnClickListener(){
     ...
    }
    builder.setNegativeButton("取消", new DialogInterface.OnClickListener(){
     ...
    }
    Dialog dialog = builder.create();
    dialog.show();
    //setSingleChoiceItems()
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    builder.setTitle();
    builder.setIcon();
    builder.setSingleChoiceItems(data,0,new DialogInterface.OnClickListener(){
      ...
    });
    Dialog dialog = builder.create();
    dialog.show();

`WebView`：

//uri , setAction , setData
    Uri uri = Uri.parse(url);
    Intent intent = new Intent();
    intent.setAction(Intent.ACTION_VIEW);
    intent.setData(uri);
    startActivity(intent);

//
    webView = findViewById(R.id.webView);
    webView.loadUrl(url);
    //
    WebSettings webSettings = webView.getSettings();
    webSettings.setJavaScriptEnabled(true);
    //
    webView.setWebViewClient(new WebViewClient(){
      ...
    });
    
    //
    webView.setWebChromeClient(new WebChromeClient(){
       ...
       //
       if(dialog != null && dialog.isShowing()){
         dialog.dismiss():
         dialog = null;
       }
       ...
       //
        if(dialog == null){
          dialog = new ProgressDialog(MainActivity.this);
          dialog.setTitle();
           ...
          dialog.show();
         }else{
           dialog.setProgress(newProgress);
         }
    }

`Fragment`：为了解决Android碎片化

Fragment is added
    onAttach()
    onCreate()
    onCreateView()
    onActivityCreated()
    onStart()
    onResume()
    Fragement is activite
    onPause()
    onStop()
    onDestroyView();
    onDestroy()
    onDetach()
    Fragment is destroyed

onCreate() onCreateView() onActivityCreated() onStart() onResume()

onPause() onStop() onStart() onResume()

onPause() onStop() onDestroyView() onDestroy() onDetach()

//
    MyFragment fragment = new MyFragment();
    FragementManager fragmentManager = getFragmentManager();
    FragmentTransaction beginTransaction = fragmentManager.beginTransaction();
    
    beginTransaction.add(R.id.layout,fragment);
    beginTransaction.commit();
    
    //
    getFragmentManager().beginTransaction().add(R.id.layout,fragment).commit();
    
    //myFragment = (MyFragment)getFragmentManager(). findFragmentById(R.id.fragment);
    //Fragment.java
    Toast.makeText(getActivity(),"dashu",Toast.LENGTH_SHORT).show();

File,SharedPreferences,SQLite

private SQLiteDatabase db;
    public class MyHelper extends SQLiteOpenHelper{ 
     public static String CREATE_TABLE="create table student("
       + " _id integer primary key autoincrement,"
       + "name varchar(20),"
       + "age integer,"
       + "sex varchar(2)";
       public Context mContext;
    
      public MyHelper(Context context,String name,SQLiteDatabase.CursorFactory factory,int version){
      super(context,name,factory,version);
      mContext=context;
    }
    @Override
    public void onCreate(SQLiteDatabase db){
     db.execSQL();
    }
    
    //
    Cursor cursor=db.query("student",null,null,null,null,null,null);
    if(cursor!=null){
      while(cursor.moveToNext()){
    
      }
    }

ContentProvider  
Android四大组件之一，为存储和获取数据提供统一的接口。  
自定义类继承ContentProvider，通过android:authorities属性授权。ContentResolver内容处理者，提供ContentProvider中同名同参的增删改查方法。

boolean onCreate()
    String getType(Uri uri)
    Cursor query()
    Uri insert()
    int update()
    int delete()
    //URI : 完整的uri路径
    //
    ContentProvider内容提供者
    ContentResolver内容解析者

Spinner下拉框

<RelativeLayout>
     <Spinner
       android:id="@+id/spinner" ...
    </RelativeLayout>
    //android:entries="@array/list"
    <resources>
      <array name="list">
       <item>1</item>
       <item>2</item>
      </array>
    </resources>

public class MainActivity extends AppCompatActivity{ 
     private Spinner mSpinner;
      ...
       //
       final String[] arrays = getResources().getStringArray(R.array.list);
      //
      ArrayAdapter<String> mSpinnerAdaper=new ArrayAdapter<String>(MainActivity.this,android.R.layout.simple_spinner_item,arrays);
        mSpinner.setAdapter(mSpinnerAdaper);
       //setOnItemSelectedListener()
       ...
    }

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[1240]: /images/20210724/e7ce824a9d78493b8f4fbd8aefc88e81.png