週記4

1. 使用TabLayout + ViewPager

佈局

    <com.google.android.material.tabs.TabLayout
        android:id="@+id/invest_tablayout"
        android:layout_width="match_parent"
        android:layout_height="80dp"
        android:paddingTop="20dp"
        android:background="@color/color_white"
        app:tabIndicatorColor="@color/colorPrimary"
        app:tabIndicatorFullWidth="false"
        app:tabSelectedTextColor="@color/colorPrimary"
        app:tabTextAppearance="@style/tab_text_size" />

    <androidx.viewpager.widget.ViewPager
        android:id="@+id/invest_viewpager"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    </androidx.viewpager.widget.ViewPager>

使用

        mFragments.clear();
        investTablayout.removeAllTabs();
        String[] arr = getResources().getStringArray(R.array.tab);
        mFragments.add(new PersonListFragment());
        mFragments.add(new PersonAddFragment());
        mFragments.add(new PersonFindFragment());
        for (int i = 0; i < arr.length; i++) {
            investTablayout.addTab(investTablayout.newTab());
        }
        investTablayout.setupWithViewPager(investViewpager, false);
        mainViewPagerAdapter = new MainViewPagerAdapter(getSupportFragmentManager(), mFragments);
        investViewpager.setAdapter(mainViewPagerAdapter);
        for (int i = 0; i < arr.length; i++) {
            investTablayout.getTabAt(i).setText(arr[i]);
        }

adapter

public class MainViewPagerAdapter extends FragmentPagerAdapter {
    private List<BaseFragment> mFragments;

    public MainViewPagerAdapter(FragmentManager fm, List<BaseFragment> cmFragments) {
        super(fm);
        mFragments = cmFragments;
    }

    @Override
    public Fragment getItem(int i) {
        return mFragments.get(i);
    }

    @Override
    public int getCount() {
        return mFragments.size();
    }
}

2. 查詢顯示動態列表

這周還做了一個人員信息查詢功能，按照輸入的字符來動態更新列表

fpfFindEt.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

            }

            @Override
            public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {

            }

            @Override
            public void afterTextChanged(Editable editable) {
                if (editable.length() == 0) {
                    fpfFindClear.setVisibility(View.INVISIBLE);
                } else {
                    fpfFindClear.setVisibility(View.VISIBLE);
                }
                handler.post(runnable);
            }
        });

3. 學習了一個彈性的自定義ScrollerView

public class ReboundScrollView extends ScrollView {

    @SuppressWarnings("unused")
    private static final String TAG = "ReboundScrollView";
    //移動的延遲距離因子,手如果滑動100 ，實際滑動60
    private static final float MOVE_FACTOR = 0.6f;
    //動畫執行的時間，也就是恢復正常的時間
    private static final int ANIM_TIME = 400;
    //ScrollView的唯一子view
    private View contentView;
    //手指觸摸起始y座標
    private float startY;
    //用來保存原始位置
    private Rect originalRect = new Rect();
    //表示是否正在移動
    private boolean isMoved = false;

    public ReboundScrollView(Context context) {
        super(context);
    }

    public ReboundScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public ReboundScrollView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    /**
     * descirption: 當我們的XML佈局被加載完後，就會回調onFinshInfalte這個方法，在這個方法中我們可以初始化控件和數據。
     */
    @Override
    protected void onFinishInflate() {
        super.onFinishInflate();
        if (getChildCount() > 0) {
            contentView = getChildAt(0);
        }
    }

    /**
     * descirption: 在測量完成之後，佈局的時候調用此方法，去保存原始位置
     */
    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        super.onLayout(changed, l, t, r, b);
        if (contentView == null)
            return;
        //保存原始位置
        originalRect.set(contentView.getLeft(), contentView.getTop(), contentView.getRight(), contentView.getBottom());
    }


    /**
     * descirption: 事件分發的方法
     */
    @Override
    public boolean dispatchTouchEvent(MotionEvent ev) {
        if (contentView == null) {
            return super.dispatchTouchEvent(ev);
        }
        int action = ev.getAction();
        switch (action) {
            case MotionEvent.ACTION_DOWN:
                Log.d(TAG, "dispatchTouchEvent: ACTION_DOWN");
                startY = ev.getY();
                break;
            case MotionEvent.ACTION_MOVE:
                Log.d(TAG, "dispatchTouchEvent: ACTION_MOVE");
                if (!isCanPullDown() && !isCanPullUp()) {
                    startY = ev.getY();
                    break;
                }
                float nowY = ev.getY();
                int deltaY = (int) (nowY - startY);
                boolean shouldMove = (isCanPullDown() && deltaY > 0)
                        || (isCanPullUp() && deltaY < 0)
                        || (isCanPullDown() && isCanPullUp());
                if (shouldMove) {
                    int offset = (int) (deltaY * MOVE_FACTOR);
                    contentView.layout(originalRect.left, originalRect.top + offset, originalRect.right,
                            originalRect.bottom + offset);
                    isMoved = true;
                }
                break;
            case MotionEvent.ACTION_UP: //鬆手就恢復原來的位置\
                Log.d(TAG, "dispatchTouchEvent: ACTION_UP");
                if (!isMoved)
                    break;
                TranslateAnimation anim = new TranslateAnimation(0, 0, contentView.getTop(), originalRect.top);
                anim.setDuration(ANIM_TIME);
                anim.setInterpolator(new DecelerateInterpolator());
                contentView.startAnimation(anim);
                contentView.layout(originalRect.left, originalRect.top, originalRect.right, originalRect.bottom);
                isMoved = false;
                break;
            default:
                break;
        }
        return super.dispatchTouchEvent(ev);
    }

    private boolean isCanPullDown() {
        return getScrollY() == 0 || contentView.getHeight() <= getHeight() + getScrollY();
    }

    private boolean isCanPullUp() {
        return contentView.getHeight() <= getHeight() + getScrollY();
    }
}