Android5.0開發範例大全 讀書筆記（三），android5.0範例

Android5.0開發範例大全 讀書筆記（三），android5.0範例

（二）使用者互動

2.14轉寄觸摸事件

1.TouchDelegate很適合簡單的觸摸轉寄，它指定任意的矩形地區來向小視圖轉寄觸摸事件，其缺點是每個被轉寄的事件都會轉寄到代理視圖的中間位置

public class TouchDelegateLayout extends FrameLayout {    public TouchDelegateLayout(Context context) {        this(context, null);    }    public TouchDelegateLayout(Context context, AttributeSet attrs) {        this(context, attrs, 0);    }    public TouchDelegateLayout(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        init(context);    }    private CheckBox mCheckBox;    private void init(Context context) {        mCheckBox = new CheckBox(context);        mCheckBox.setText("tap anywhere");        addView(mCheckBox, new LinearLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT, Gravity.CENTER));    }    @Override    protected void onSizeChanged(int w, int h, int oldw, int oldh) {        if (w != oldw || h != oldh) {            Rect rect = new Rect(0, 0, w, h);            TouchDelegate touchDelegate = new TouchDelegate(rect, mCheckBox);            setTouchDelegate(touchDelegate);        }    }}

 2.自訂觸摸轉寄

  在onTouch中改變event事件資訊

 @Override    public boolean onTouch(View v, MotionEvent event) {        event.setLocation(event.getX(),event.getY()/2);        scrollView.dispatchTouchEvent(event);        return true;    }

2.15阻止觸摸竊賊

1. 調用requestDisallowTouchIntercept()方法，請求父控制項不要截獲當前的觸摸事件

2.16建立拖放視圖

拖1.使用DragShadowBuilder構造被拖動視圖的外觀

2.調用View.startDrag()開啟拖動

 @Override    public boolean onLongClick(View v) {        View.DragShadowBuilder shadowBuilder=new View.DragShadowBuilder(v);        v.startDrag(null, shadowBuilder, ((ImageView) v).getDrawable(),0);        return true;    }

放

3.通過OnDragListener.onDrag()監聽拖動的事件，可以自訂一個視圖實現listener介面，以下為核心代碼

 @Override    public boolean onDrag(View v, DragEvent event) {        PropertyValuesHolder pvhX, pvhY;        switch (event.getAction()) {            case DragEvent.ACTION_DRAG_STARTED:                pvhX = PropertyValuesHolder.ofFloat("scaleX", 0.5f);                pvhY = PropertyValuesHolder.ofFloat("scaleY", 0.5f);                ObjectAnimator.ofPropertyValuesHolder(this, pvhX, pvhY).start();                setImageDrawable(null);                mDropped = false;                break;            case DragEvent.ACTION_DRAG_ENDED:                if (!mDropped) {                    pvhX = PropertyValuesHolder.ofFloat("scaleX", 1f);                    pvhY = PropertyValuesHolder.ofFloat("scaleY", 1f);                    ObjectAnimator.ofPropertyValuesHolder(this, pvhX, pvhY).start();                    mDropped = false;                }                break;            case DragEvent.ACTION_DRAG_ENTERED:                pvhX = PropertyValuesHolder.ofFloat("scaleX", 0.75f);                pvhY = PropertyValuesHolder.ofFloat("scaleY", 0.75f);                ObjectAnimator.ofPropertyValuesHolder(this, pvhX, pvhY).start();                break;            case DragEvent.ACTION_DRAG_EXITED:                pvhX = PropertyValuesHolder.ofFloat("scaleX", 0.5f);                pvhY = PropertyValuesHolder.ofFloat("scaleY", 0.5f);                ObjectAnimator.ofPropertyValuesHolder(this, pvhX, pvhY).start();                break;            case DragEvent.ACTION_DROP:                Keyframe frame0=Keyframe.ofFloat(0f,0.75f);                Keyframe frame1=Keyframe.ofFloat(0.5f,0f);                Keyframe frame2=Keyframe.ofFloat(1f,0.75f);                pvhX = PropertyValuesHolder.ofKeyframe("scaleX", frame0,frame1,frame2);                pvhY = PropertyValuesHolder.ofKeyframe("scaleY", frame0, frame1, frame2);                ObjectAnimator.ofPropertyValuesHolder(this, pvhX, pvhY).start();                setImageDrawable((Drawable) event.getLocalState());                mDropped=true;                break;            default:                return false;        }        return true;    }

2.17構建導航Drawer

1.DrawerLayout只在Android支援庫中提供，關鍵點在於設定gravity的屬性

<?xml version="1.0" encoding="utf-8"?><android.support.v4.widget.DrawerLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:id="@+id/drawer_layout"    android:layout_width="match_parent"    android:layout_height="match_parent">    <FrameLayout        android:id="@+id/middle"        android:layout_width="match_parent"        android:layout_height="match_parent"/>    <ListView        android:id="@+id/left"        android:layout_width="240dp"        android:layout_height="match_parent"        android:layout_gravity="left"        android:background="#555"/>    <LinearLayout        android:id="@+id/right"        android:layout_width="240dp"        android:layout_height="match_parent"        android:layout_gravity="right"        android:orientation="vertical"        android:background="#ccc">        <TextView            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="this is right"/>    </LinearLayout></android.support.v4.widget.DrawerLayout>

2.當DrawerLayout與ActionBar結合時，要使用ActionBarDrawerToggle

 mToggle = new ActionBarDrawerToggle(this, mDrawerContainer, R.string.open, R.string.close) {            @Override            public void onDrawerOpened(View drawerView) {                super.onDrawerOpened(drawerView);                supportInvalidateOptionsMenu();            }            @Override            public void onDrawerStateChanged(int newState) {                super.onDrawerStateChanged(newState);                supportInvalidateOptionsMenu();            }            @Override            public void onDrawerClosed(View drawerView) {                super.onDrawerClosed(drawerView);                supportInvalidateOptionsMenu();            }        };

3.與ToolBar結合時，和之前類似有兩個要點，一是主題的風格，二是調用setActionBar(toolbar)方法

2.18在視圖之間滑動

1.定義PagerAdapter實現介面的布局,主要方法是instantiateItem()

public class ImagePagerAdapter extends PagerAdapter {    private Context mContext;    private static final int[] IMAGES = {            android.R.drawable.ic_menu_camera,            android.R.drawable.ic_menu_add,            android.R.drawable.ic_menu_delete,            android.R.drawable.ic_menu_share,            android.R.drawable.ic_menu_edit    };    private static final int[] COLORS = {            Color.RED,            Color.BLUE,            Color.GREEN,            Color.GRAY,            Color.MAGENTA    };    public ImagePagerAdapter(Context context) {        super();        mContext = context;    }    @Override    public int getCount() {        return IMAGES.length;    }    @Override    public float getPageWidth(int position) {        return 0.333f;    }    @Override    public boolean isViewFromObject(View view, Object object) {        return (view == object);    }    @Override    public Object instantiateItem(ViewGroup container, int position) {        ImageView iv = new ImageView(mContext);        iv.setImageResource(IMAGES[position]);        iv.setBackgroundColor(COLORS[position]);        container.addView(iv);        return iv;    }    @Override    public void destroyItem(ViewGroup container, int position, Object object) {        container.removeView((View) object);    }}

2.將adaper與viewpager適配

 @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        ImagePagerAdapter adapter=new ImagePagerAdapter(this);        ViewPager viewPager=new ViewPager(this);        viewPager.setAdapter(adapter);        setContentView(viewPager);    }

2.18使用選項卡導航

1在sample中有一個SlidingTabBasic SDK,首先要將其中的SlidingTabLayout和SlidingTabStrip複製到自己的項目中

2.接著通過TabsPagerAdapter進行內容的適配，核心方法依然是instantiateItem()

private static class TabsPagerAdapter extends PagerAdapter {        private Context mContext;        public TabsPagerAdapter(Context mContext) {            this.mContext = mContext;        }        @Override        public CharSequence getPageTitle(int position) {            switch (position) {                case 0:                    return "PRIMARY";                case 1:                    return "SECONDARY";                case 2:                    return "TERTIARY";                case 3:                    return "QUATERNARY";                case 4:                    return "QUINARY";                default:                    return "";            }        }        @Override        public int getCount() {            return 5;        }        @Override        public Object instantiateItem(ViewGroup container, int position) {            ImageView imageView = new ImageView(mContext);            imageView.setScaleType(ImageView.ScaleType.CENTER);            imageView.setImageResource(R.mipmap.ic_launcher);            container.addView(imageView);            return imageView;        }        @Override        public boolean isViewFromObject(View view, Object object) {            return view == object;        }        @Override        public void destroyItem(ViewGroup container, int position, Object object) {            container.removeView((View) object);        }    }

3.最後在activity中調用即可

 @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_action_tabs);        ViewPager pager = (ViewPager) findViewById(R.id.pager);        SlidingTabLayout tabLayout = (SlidingTabLayout) findViewById(R.id.tabs);        assert pager != null;        pager.setAdapter(new TabsPagerAdapter(this));        assert tabLayout != null;        tabLayout.setViewPager(pager);        tabLayout.setCustomTabColorizer(new SlidingTabLayout.TabColorizer() {            @Override            public int getIndicatorColor(int position) {                return Color.WHITE;            }            @Override            public int getDividerColor(int position) {                return 0;            }        });    }

4.Google內建的sample種有很多牛逼的例子，等考完軟考，就把官方的文檔和那些API例子一個一個懟掉