侧滑菜单HorizontalScrollView，类中如何使用intent跳转

布局文件main.xml

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

    <MyHorizontalScrollView
        android:id="@+id/layout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:scrollbars="none">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="horizontal" >

            <include layout="@layout/horizontalscrollview"/>
            <ListView
                 android:id="@+id/listView_msg"
                 android:layout_width="match_parent"
                 android:layout_height="match_parent"
                 android:layout_marginBottom="65dp"></ListView>
        </LinearLayout>
    </MyHorizontalScrollView>
</LinearLayout>

侧滑的布局myhorizontalscrollView.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">

    <Button
        android:id="@+id/quit_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/quit"/>

</LinearLayout>

HorizontalScrollView类

public class MyHorizontalScrollView extends HorizontalScrollView {

    // 在HorizontalScrollView有个LinearLayout
    private LinearLayout linearLayout;
    // 菜单，内容页
    private ViewGroup myMenu;
    private ViewGroup myContent;
    // 菜单宽度
    private int myMenuWidth;
    // 屏幕宽度
    private int screenWidth;
    // 菜单与屏幕右侧的距离(dp)
    private int myMenuPaddingRight = 50;
    // 避免多次调用onMeasure的标志
    private boolean once = false;

    public MyHorizontalScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);

        // 获取屏幕宽度
        WindowManager windowManager = (WindowManager) context
                .getSystemService(Context.WINDOW_SERVICE);
        DisplayMetrics outMetrics = new DisplayMetrics();
        windowManager.getDefaultDisplay().getMetrics(outMetrics);
        screenWidth = outMetrics.widthPixels;// 屏幕宽度

        // 将dp转换px
        myMenuPaddingRight = (int) TypedValue.applyDimension(
                TypedValue.COMPLEX_UNIT_DIP, 50, context.getResources()
                        .getDisplayMetrics());
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        if (!once) {// 使其只调用一次
            // this指的是HorizontalScrollView，获取各个元素
            linearLayout = (LinearLayout) this.getChildAt(0);// 第一个子元素
            myMenu = (ViewGroup) linearLayout.getChildAt(0);// HorizontalScrollView下LinearLayout的第一个子元素
            //退出登录
            Button quitButton = (Button) myMenu.findViewById(R.id.quit_button);
            quitButton.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {
                    Log.i("MyHorizontalScrollView", "quit");

                    //退出登录
                    EMClient.getInstance().logout(true);

                    //跳转到登录界面（activity是context的子类）
                    Intent intent = new Intent(getContext(), LoginActivity.class);
                    getContext().startActivity(intent);
                    //activity是context的子类,可以转换
                    ((Activity)getContext()).finish(); 

                }
            });
            myContent = (ViewGroup) linearLayout.getChildAt(1);// HorizontalScrollView下LinearLayout的第二个子元素

            // 设置子View的宽高，高于屏幕一致
            myMenuWidth = myMenu.getLayoutParams().width = screenWidth
                    - myMenuPaddingRight;// 菜单的宽度=屏幕宽度-右边距
            myContent.getLayoutParams().width = screenWidth;// 内容宽度=屏幕宽度
            // 决定自身View的宽高，高于屏幕一致
            // 由于这里的LinearLayout里只包含了Menu和Content所以就不需要额外的去指定自身的宽
            once = true;
        }
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        super.onLayout(changed, l, t, r, b);

        if (changed) {
            this.scrollTo(myMenuWidth, 0); // 没有动画效果的隐藏
        }
    }

    @Override
    public boolean onTouchEvent(MotionEvent ev) {

        int action = ev.getAction();
        switch (action) {
            case MotionEvent.ACTION_UP:
                int scrollX = this.getScrollX();// 滑动的距离scrollTo方法里，也就是onMeasure方法里的向左滑动那部分
                if (scrollX >= myMenuWidth / 2) {
                    this.smoothScrollTo(myMenuWidth, 0);// 向左滑动展示内容
                } else {
                    this.smoothScrollTo(0, 0);
                }
                return true;
        }
        return super.onTouchEvent(ev);
    }

}