Android开发工程师文集-Fragment，适配器，轮播图，ScrollView，Gallery 图片浏览器，Android常用布局样式

刺骨的言语ヽ痛彻心扉 2021-09-15 11:34 175阅读 0赞

> Android开发工程师文集-Fragment，适配器，轮播图，ScrollView，Gallery 图片浏览器，Android常用布局样式

## Fragment ##

FragmentManager fragmentManager = getFragmentManager();
    FragmentTransaction beginTransaction = fragmentManager.beginTransaction();

事务

add(),remove(),replace(),commit()

MyFragment2 fragment2=new MyFragment2(); FragmentManager fragmentManager = getFragmentManager(); FragmentTransaction beginTransaction = fragmentManager.beginTransaction(); beginTransaction.add(R.id.frame,fragement2); beginTransaction.commit();

fragment的生命周期

Created

onAttach()->onCreate()->onCreateView()->onActivityCreated()

Started

onStart()

Resumed

onResume()

Paused

onPause()

Stopped

onStop()

Destroyed

onDestroyView()->onDestroy()->onDetach()

//当Fragment被添加到Activity的时候回调这个方法，并且只调用一次 @Override public void onAttach(Activity activity){ super.onAttach(activity); }

//创建Fragment时会回调，只调用一次 @Override public void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); }

//每次创建回调 @Override public View onCreateView(## ##){ }

//当Fragment所在的Activity启动完成后调用 @Override public void onActivityCreated(Bundle savedInstanceState){ super.onActivityCreated(savedInstanceState); }

//启动onStart() @Override public void onStart(){ super.onStart(); }

//onResume @Override public void onResume(){ super.onResume(); }

//onPause 暂停 @Override public void onPause(){ super.onPause(); }

//onStop 停止 @Override public void onStop(){ super.onStop(); }

//last

//onDestroyView @Override public void onDestroyView(){ super.onDestroyView(); }

//销毁

//onDestroy @Override public void onDestroy(){ super.onDestroy(); }

重点  
删除Fragment  
//onDetach

@Override public void onDetach(){ super.onDetach(); }

## 启动Fragment ##

> onAttach()->onCreate()->onCreateView()->onActivityCreated()->onStart()->onResume()

暂停Fragment - //暂停和停止的方法

> onPause()->onStop()

重新看到Fragment

> onStart()->onResume()

Fragment1 -> Fragment2

Fragment1: onPause()->onStop()->onDestroyView->onDestroy()->onDetach() Fragment2: onAttach()->onCreate()->onCreateView()->onActivityCreated()->onStart()->onResume()

Fragment2回到主界面时

> onPause()->onStop()

又重新看见

//Fragment2回到界面 onStart()->onResume()

Fragment2 退出

onPause()->onStop()->onDestroyView()->onDestroy()->onDetach()

## Fragment与Activity ##

1.  Fragment是通过调用getActivity()的方法获取Activity的；
2.  Activity是通过调用FragmentManager的findFramentById()的，也可以用findFragmentByTag()方法获取Fragment片段的。

## 重点 ##

public class MyFragment extends Fragment{ @Override public View onCreateView(LayoutInflater inflater,ViewGrop container,Bundle savedInstanceState){ return super.onCreateView(inflater,container,savedInstanceState); //View view = inflater.inflate(R.layout.fragment, container, false); //TextView tv = view.findViewById(R.id.textview); //return view; } }

一个Activity调用Fragment的界面显示数据内容

String text = editext.getText().toString(); MyFragment fragment = new MyFragment(); Bundle bundle = new Bundle(); bundle.putString("name",text); fragment.setArguments(bundle); FragmentManager fragmentManager = getFragmentManager(); FragmentTransaction beginTransaction = fragmentManager.beginTransaction(); //beginTransaction.add(containerViewId,fragment,tag) beginTransaction.add(R.id.layout.textview,fragment,"fragment"); beginTransaction.commit();

在Fragement中设置

public class MyFragment extends Fragment{ @0verride public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){ View view = inflater.infate(R.layout.fragement,container,false); TextView tv=view.findViewById(R.id.textview); String text = getArguments().get("name")+""; tv.setText(text); } }

Fragment

private String name = "v"; public interface Myvoid { public void name(String name); }

Activity

implements Myvoid

fragment

@Override public void onAttach(Activity activity){ myvoid = activity; super.onAttach(activity); }

回到Activity

覆盖方法

## 另类 ##

xml

<?xml version="1.0" encoding="utf-8"?>
    <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" android:background="@android:color/white" android:orientation="vertical">
        
    </LinearLayout>

Fragment

public class MyinfoFragment extends Fragment implements View.OnClickListener{ @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { return inflater.inflate(R.layout.fragment_myinfo, null); } @Override public void onViewCreated(View view, Bundle savedInstanceState) { super.onViewCreated(view, savedInstanceState); } @Override public void onClick(View v) { } }

MainActivity

public class MainActivity extends FragmentActivity implements View.OnClickListener{ @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initView(); setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_PORTRAIT); setMain(); } @Override public boolean onKeyDown(int keyCode, KeyEvent event) { } private void setMain() { } @Override protected void onActivityResult(int requestCode, int resultCode, Intent data) { super.onActivityResult(requestCode, resultCode, data); } private void setSelectStatus(int index) { switch (index){ } } private void initView() { } @Override public void onClick(View v) { switch (v.getId()){ } } }

## 继续 ##

FragmentManager fragmentManager = getFragmentManager();
    Fragment findFragmentById = fragmentManager.findFragmentById(R.id.fragment);

## ViewPager左右滑动 ##

<android.support.v4.view.ViewPager android:id="@+id/viewpager" android:... android:...>
    </android.support.v4.view.ViewPager>

> ViewPager是一种容器，可以盛装两种类型的对象：一种是View对象； 也可以放置Fragment。

getLayoutInflater().form(this); getLayoutInflater().form(this).inflate(resource,root);

## 配置Adapter： ##

> 准备数据源 -> 准备适配器 ->加载适配器

List<View>  
PagerAdapter

ViewPager的声明：`<android.support.v4.view.ViewPager>`  
是为了解决版本兼容性问题

## 过程 ##

我们创建好布局文件，然后在MainActivity中添加，进行实例

准备数据源

private List<View> viewList;

viewList = new ArrayList<View>();

显示

View view = View.inflate(this, R.layout.view, null);

添加

viewList.add(view);

## 准备适配器 ##

@Override public Object instantiateItem(ViewGroup container, int position){ }

搭建构造方法

public MyPagerAdapter(List<View> viewList){ this.viewList=viewList; }

container.addview(); return viewList.get(position);

container.removeView(viweList.get(position));

## Adapter ##

创建Adapter

PagerAdapter pagerAdapter = new PagerAdapter(viewList);

> setAdapter(pagerAdapter);

## 对象 ##

> PagerTabStrip和PagerTitleStrip

一个View显示ViewPager，然后在ViewPager中添加PagerTabStrip <android.support.v4.view.ViewPager ... <android.support.v4.view.PagerTabStrip ...> </android.support.v4.view.PagerTabStrip> </android.support.v4.view.ViewPager>

然后加入标题，`private List<String> titleList;`

同理，ViewPager添加题目

titleList = new ArrayList<String>(); titleList.add("第一题")； titleList.add("第二题")； titleList.add("第三题")； titleList.add("第五题");

在加入PagerAdapter中，创建Adapter下创建，MyPagerAdapter.java

MyPagerAdapter.java

public class MyPagerAdapter extends PagerAdapter{ private List<View> viewList; private List<String> titleList; public MyPagerAdapter(List<View> viewList, List<String> titleList){ this.viewList=viewList; this.titleList=titleList; } }

加入题目数量第几题  
显示标题  
getPageTitle(),显示所对应的标题

@Override public CharSequence getPageTitle(int position){ //return super.getPageTitle(position); return titleList.get(position); }

PagerTabStrip的属性  
背景

> setBackgroundColor(Color.RED);  
> 文本  
> setTextColor();  
> 下划线  
> setDrawFullUnderline(false);  
> 分割线  
> setTabIndicatorColor();

## PagerTitleStrip 与 PagerTabStrip 类似 ##

## 适配器 ##

> FragmentPagerAdapter

import android.os.Bundle; import android.support.v4.app.Fragment; public class ExercisesFragment extends Fragment { private ListView lvList;//来源fragment private ListItemAdapter adapter; //适配器 private List<> ebl; //列表集合 @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { return inflater.inflate(R.layout.fragment, null); } @Override public void onViewCreated(View view, Bundle savedInstanceState) { super.onViewCreated(view, savedInstanceState); initData(); lvList = view.findViewById(R.id.lv_list); adapter = new ListItemAdapter(getActivity()); adapter.setData(ebl); lvList.setAdapter(adapter); } private void initData(){ ebl = new ArrayList<Bean>(); for (int i=0;i<10;i++){ Bean bean = new Bean(); bean.id=(i+1); switch (i){ case 0: case 9: default: break; } } } }

设置MyFragment继承Fragment

public class MyFragment extends Fragment{ @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState){ return inflater.infate(R.layout.view, container, false); //return inflater.infate(R.layout.view, null); } }

点击跳转Fragment

public void onClick(View v) { switch (v.getId()){ case R.id.bottom1: //getSupportFragmentManager().beginTransaction().add(R.id.main_body,new CFragment()).commit(); break; case R.id.bottom2: //getSupportFragmentManager().beginTransaction().add(R.id.main_body,new EFragment()).commit(); break; case R.id.bottom3: //getSupportFragmentManager().beginTransaction().add(R.id.main_body,new MFragment()).commit(); break; } }

实例

private List<Fragment> fragmentList;

Fragment作为数据源

添加Fragment fragmentList = new ArrayList<Fragment>(); fragmentList.add(new Fragment()); 添加创建的Fragment //fragmentList.add(new Fragment%());

导入的包

import android.support.v4.app.Fragment;

## 配置数据适配器 ##

如果用FragmentPagerAdapter，一次性加载  
同理

public class MyFragment extends FragmentPagerAdapter{ private List<Fragment> fragmentList; private List<String> titleList; public MyFragment(FragmentManager fm，List<Fragment> fragmentList，List<String> titleList){ super(fm) this.fragmentList=fragmentList; this.titleList=titleList; } }

MainActivity.java

public class MainActivity extends FragmentActivity implements View.OnClickListener{ @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); } private void setMain() { } private void setSelectStatus(int index) { switch (index){ } } private void initView() { } @Override public void onClick(View v) { switch (v.getId()){ //getSupportFragmentManager().beginTransaction().add(R.id.main_body,new CourseFragment()).commit(); //getSupportFragmentManager().beginTransaction().add(R.id.main_body,new ExercisesFragment()).commit(); //getSupportFragmentManager().beginTransaction().add(R.id.main_body,new MyinfoFragment()).commit(); } } }

FragmentPagerAdapter adapter=new FragmentPagerAdapter(getSupportFragmentManager());

## 轮播图 ##

## ViewFlipper ##

自动播放

静态的方法导入：

动态导入：

flipper = findViewById(R.id.flipper);  
flipper.addView(getImageView(R.drawable.picture));

自己定义动态效果，一般用anim的文件夹表示：

然后创建布局界面：  
创建轮播图

MainActivity.java

public class MainActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState){ super.onCreate(savedInstanceState); setContentView(R.layout.main); } }

声明变量

private ViewFlipper flipper;

进行初始化

flipper = findViewById(R.id.flipper);

动态导入：addView(getImageView(R.drawable.picture));

轮播图有多张图片，创建数组，分别导入

获取图片

private ImageView getImageView(int imageId){ ImageView image = new ImageView(this); image.setImageResource(imageId); return image; }

for(int i=0; i<imageId.length;i++){ flipper.addView(getImageView( 数组[i] )); }

手势滑动的方法

@Override public boolean onTouchEvent(MotionEvent event){ return super.onTouchEvent(event); }

自动播放效果：

flipper.setFlipInterval(3000); flipper.startFlipping();

## ScrollView ##

HorizontalScrollView,ScrollView

滚动视图

不能滚动，因为布局不是ScrollVeiw，而是`<TextView>`

tv.setText(getResources().getString(R.string.content));

如果是这样就可以

setOnTouchListener的方法

scroll.setOnTouchListener(new OnTouchListener){ }

> 记得 scrollBy 和 scrollTo 的区别

## Gallery 图片浏览器 ##

Gallery像一个走廊，ImageSwitcher像幻灯片

显示图片，就要对图片进行封装，声明数组

布局
    <Gallery android:... />
     老样子

图片id,`private int[] res 定义数组`

我们学过的适配器，都是继承BaseAdapter

ArrayAdapter<String> adapter; SimpleAdapter adapter;

## 继承BaseAdapter中必须要实现的方法 ##

1.  public int getCount()
2.  public long getItemId(int position)
3.  public Object getItem(int position)
4.  public View gtView(int position, View convertView, ViewGroup parent)

如果自己定义一个适配器，定义后，实现BaseAdapter中的方法，  
然后创建构造函数

private int[] images; public ImageAdapter(int []images) { this.images = images; }

### 说明 ###

获取视图

private Context context; public ImageAdapter(int[] images, Context context){ this.images = images; this.context = context; }

> public View gtView(int position, View convertView, ViewGroup parent)

{ //ImageView image=new ImageView(this); ImageView image = new ImageView(context); image.setBackgroundResource(数组[position]); //设置图片大小 image.setLayoutParams(new Gallery.LayoutParams(400,300)); return image; }

加载适配器 MainActivity.java

声明适配器： private ImageAdapter adapter;

初始化： adapter = new ImageAdapter(数组的变量名，上下文(this));

gallery.setAdapter(adapter);

无限制浏览

return Interger.MAX\_VALUE;

## 监听器 ##

setOnItemSelectedListener(this);

同样<ImageSwitcher>也要布局

声明 private ImageSwitcher is;

进行初始化 is = findViewById(R.id.is);

监听器：gallery.setOnItemSelectedListener(this);