Android实现左滑退出Activity（完美封装）

1：定义一个自己的父级容器，让它继承自一个布局（LinearLayout、RelativeLayout都可以）

public class SildingFinishLayout extends RelativeLayout implements View.OnTouchListener {
    /**
     * SildingFinishLayout布局的父布局
     */
    private ViewGroup mParentView;
    /**
     * 处理滑动逻辑的View
     */
    private View touchView;
    /**
     * 滑动的最小距离
     */
    private int mTouchSlop;
    /**
     * 按下点的X坐标
     */
    private int downX;
    /**
     * 按下点的Y坐标
     */
    private int downY;
    /**
     * 临时存储X坐标
     */
    private int tempX;
    /**
     * 滑动类
     */
    private Scroller mScroller;
    /**
     * SildingFinishLayout的宽度
     */
    private int viewWidth;
    /**
     * 记录是否正在滑动
     */
    private boolean isSilding;


    private OnSildingFinishListener onSildingFinishListener;
    private boolean isFinish;


    public SildingFinishLayout(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }


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


        mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
        mScroller = new Scroller(context);
    }


    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        super.onLayout(changed, l, t, r, b);
        if (changed) {
// 获取SildingFinishLayout所在布局的父布局
            mParentView = (ViewGroup) this.getParent();
            viewWidth = this.getWidth();
        }
    }


    /**
     * 设置OnSildingFinishListener, 在onSildingFinish()方法中finish Activity
     *
     * @param onSildingFinishListener
     */
    public void setOnSildingFinishListener(
            OnSildingFinishListener onSildingFinishListener) {
        this.onSildingFinishListener = onSildingFinishListener;
    }


    /**
     * 设置Touch的View
     *
     * @param touchView
     */
    public void setTouchView(View touchView) {
        this.touchView = touchView;
        touchView.setOnTouchListener(this);
    }


    public View getTouchView() {
        return touchView;
    }


    /**
     * 滚动出界面
     */
    private void scrollRight() {
        final int delta = (viewWidth + mParentView.getScrollX());
// 调用startScroll方法来设置一些滚动的参数，我们在computeScroll()方法中调用scrollTo来滚动item
        mScroller.startScroll(mParentView.getScrollX(), 0, -delta + 1, 0,
                Math.abs(delta));
        postInvalidate();
    }


    /**
     * 滚动到起始位置
     */
    private void scrollOrigin() {
        int delta = mParentView.getScrollX();
        mScroller.startScroll(mParentView.getScrollX(), 0, -delta, 0,
                Math.abs(delta));
        postInvalidate();
    }


    /**
     * touch的View是否是AbsListView， 例如ListView, GridView等其子类
     *
     * @return
     */
    private boolean isTouchOnAbsListView() {
        return touchView instanceof AbsListView ? true : false;
    }


    /**
     * touch的view是否是ScrollView或者其子类
     *
     * @return
     */
    private boolean isTouchOnScrollView() {
        return touchView instanceof ScrollView ? true : false;
    }


    @Override
    public boolean onTouch(View v, MotionEvent event) {
        switch (event.getAction()) {
            case MotionEvent.ACTION_DOWN:
                downX = tempX = (int) event.getRawX();
                downY = (int) event.getRawY();
                break;
            case MotionEvent.ACTION_MOVE:
                int moveX = (int) event.getRawX();
                int deltaX = tempX - moveX;
                tempX = moveX;
                if (Math.abs(moveX - downX) > mTouchSlop
                        && Math.abs((int) event.getRawY() - downY) < mTouchSlop) {
                    isSilding = true;


// 若touchView是AbsListView，
// 则当手指滑动，取消item的点击事件，不然我们滑动也伴随着item点击事件的发生
                    if (isTouchOnAbsListView()) {
                        MotionEvent cancelEvent = MotionEvent.obtain(event);
                        cancelEvent
                                .setAction(MotionEvent.ACTION_CANCEL
                                        | (event.getActionIndex() << MotionEvent.ACTION_POINTER_INDEX_SHIFT));
                        v.onTouchEvent(cancelEvent);
                    }


                }


                if (moveX - downX >= 0 && isSilding) {
                    mParentView.scrollBy(deltaX, 0);


// 屏蔽在滑动过程中ListView ScrollView等自己的滑动事件
                    if (isTouchOnScrollView() || isTouchOnAbsListView()) {
                        return true;
                    }
                }
                break;
            case MotionEvent.ACTION_UP:
                isSilding = false;
                if (mParentView.getScrollX() <= -viewWidth / 2) {
                    isFinish = true;
                    scrollRight();
                } else {
                    scrollOrigin();
                    isFinish = false;
                }
                break;
        }


// 假如touch的view是AbsListView或者ScrollView 我们处理完上面自己的逻辑之后
// 再交给AbsListView, ScrollView自己处理其自己的逻辑
        if (isTouchOnScrollView() || isTouchOnAbsListView()) {
            return v.onTouchEvent(event);
        }


// 其他的情况直接返回true
        return true;
    }


    @Override
    public void computeScroll() {
// 调用startScroll的时候scroller.computeScrollOffset()返回true，
        if (mScroller.computeScrollOffset()) {
            mParentView.scrollTo(mScroller.getCurrX(), mScroller.getCurrY());
            postInvalidate();


            if (mScroller.isFinished()) {


                if (onSildingFinishListener != null && isFinish) {
                    onSildingFinishListener.onSildingFinish();
                }
            }
        }
    }


    public interface OnSildingFinishListener {
        public void onSildingFinish();
    }


}

2.Acitity

在Activity的onCreate（）方法里面  
 @Override
    public void onCreate(@Nullable Bundle savedInstanceState, @Nullable PersistableBundle persistentState) {
        super.onCreate(savedInstanceState, persistentState);
        SildingFinishLayout mSildingFinishLayout = (SildingFinishLayout) findViewById(R.id.timed_task_SildingFinishLayout);
mSildingFinishLayout
        mSildingFinishLayout .setOnSildingFinishListener(new SildingFinishLayout.OnSildingFinishListener() {
            @Override
            public void onSildingFinish() {
                finish();
            }
        });
        mSildingFinishLayout .setTouchView(mSildingFinishLayout);//绑定底层的布局就可以了  :不起作用的话换个你activity 布局里面view就可以啦 
    }
截止目前，这个功能已经实现了

解决问题:这个会出现左滑 背景白色问题
1.style.xml中中增加

<style name="AppTheme" parent="android:Theme.Light">
    <item name="android:windowIsTranslucent">true</item>
    <item name="android:windowNoTitle">true</item>
    <item name="android:windowBackground">@android:color/transparent</item>
</style>

2 acvitiy 的属性中加上

android:theme="@style/AppTheme" 

3 一些属性的详解

<item name="android:windowFrame">@null</item> ：Dialog的windowFrame框为无
<item name="android:windowIsFloating">true</item>：是否浮现在activity之上
<item name="android:windowIsTranslucent">false</item>:是否半透明
<item name="android:windowNoTitle">true</item>:是否显示title
<item name="android:windowBackground">@drawable/dia_bg</item>:设置dialog的背景
<item name="android:backgroundDimEnabled">false</item>: 背景是否透明显示

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