自定义 HorizontalScrollView

19号下午4点 老板突然觉得导航条不好看， 要做成和别的app一样。 然而20号要上线 真是醉人，加班做了个 HorizontalScrollView。 今天重新封装成控件 。 增加动态 改变文字

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <declare-styleable name="MyHorizontalScrollView">

        <attr name="textSize" format="integer"/>
        <attr name="leftPadding" format="integer"></attr>
        <attr name="rightPadding" format="integer"></attr>
        </declare-styleable>

</resources>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:wk="http://schemas.android.com/apk/res/com.example.x6.myhorizontalscrollview"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.x6.myhorizontalscrollview.MainActivity">


    <com.example.x6.myhorizontalscrollview.MyHorizontalScrollView
        android:id="@+id/hol"
        android:layout_width="match_parent"
        android:layout_height="40dp"
        wk:textSize="15"
        wk:leftPadding="10"
        wk:rightPadding="10"
        ></com.example.x6.myhorizontalscrollview.MyHorizontalScrollView>
</RelativeLayout>

public class MainActivity extends AppCompatActivity {

    private String[] data = {"哈","哈1","哈11","哈123","哈1234","哈5342"
            ,"哈沙发","哈案案发的方式","哈问问特如果","哈",};

    private String[] data2 = {"改变1","改变123","改变地方","改变45区v","改变234地方","改变"
            ,"改变","改变2热情为让发的是犯法","改变","改变",};

    private Handler handler = new Handler() {
        @Override
        public void handleMessage(Message msg) {
            hol.addTag(data);
        }
    };
    private MyHorizontalScrollView hol;
    private Button btn;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        hol = (MyHorizontalScrollView) findViewById(R.id.hol);
        btn = (Button) findViewById(R.id.btn);

        //网络获取数据 延时 1S
        handler.sendEmptyMessageDelayed(0,1000);


        hol.setListener(new MyHorizontalScrollView.OnTouchLetterChangedListener() {
            @Override
            public void onTouchLetterChanged(int index) {
                Toast.makeText(MainActivity.this,"当前点击:"+index,Toast.LENGTH_SHORT).show();
            }
        });

        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                hol.addTag(data2);
            }
        });
    }
}

public class MyHorizontalScrollView extends HorizontalScrollView {

    private Context context;

    private LinearLayout linLayout;
    private int width;
    private int height;
    private int textSize;
    private int leftPadding;
    private int rightPadding;
    private List<Integer> moveXList = new ArrayList<>();
    private List<TextView> tvList = new ArrayList<>();


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

    public MyHorizontalScrollView(Context context, AttributeSet attrs) {
        super(context, attrs);
        this.context = context;
        init(context,attrs);
    }

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

    private void init(Context context,AttributeSet attrs) {
        TypedArray ta= context.obtainStyledAttributes(attrs,R.styleable.MyHorizontalScrollView);
        textSize = ta.getInteger(R.styleable.MyHorizontalScrollView_textSize,15);
        leftPadding = ta.getInteger(R.styleable.MyHorizontalScrollView_leftPadding,15);
        rightPadding = ta.getInteger(R.styleable.MyHorizontalScrollView_rightPadding,15);
        ta.recycle();
    }

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

        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
        width = MeasureSpec.getSize(widthMeasureSpec);
        height = MeasureSpec.getSize(heightMeasureSpec);

        initChildX();
    }

    //计算 textview的宽度
    private void initChildX(){
        if(getChildCount()>0){
            ViewGroup view = (ViewGroup) getChildAt(0);
            if(view.getChildCount()>0){
                moveXList.clear();
                //第一个数据 无需移动
                moveXList.add(0);
                int moveX = 0;
                for(int i=0; i<view.getChildCount()-1; i++){
                    moveX += view.getChildAt(i).getMeasuredWidth();
                    moveXList.add(moveX);
                }
            }
        }
    }

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

    private void addLinLayout(Context context) {

        if(this.getChildCount()==1)return ;

        LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(
                width,height);
        linLayout = new LinearLayout(context);
        linLayout.setGravity(LinearLayout.HORIZONTAL);
        this.addView(linLayout,layoutParams);
    }

    public void addTag(String[] data) {

        if(linLayout!=null)
            linLayout.removeAllViews();

        for(int i=0; i<data.length; i++){

            LinearLayout.LayoutParams titleLayout = new LinearLayout.LayoutParams(
                    ViewGroup.LayoutParams.WRAP_CONTENT,
                    height);

            TextView tv = new TextView(context);
            if(i == 0){
                tv.setTextColor(0xff46abff);
            }else{
                tv.setTextColor(0xff333333);
            }

            tv.setText(data[i]);
            tv.setTextSize(TypedValue.COMPLEX_UNIT_SP, textSize);
            tv.setGravity(Gravity.VERTICAL_GRAVITY_MASK);
            tv.setPadding(dip2px(context,leftPadding), 0, dip2px(context,rightPadding), 0);

            final int index = i;
            tv.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {
                    smoothScrollTo(moveXList.get(index),0);
                    for(int n=0; n<tvList.size(); n++){
                        tvList.get(n).setTextColor(0xFF333333);
                    }
                    ((TextView) v).setTextColor(0xFF46ABFF);
                    listener.onTouchLetterChanged(index);
                }
            });
            tvList.add(tv);
            if(linLayout!=null)
                linLayout.addView(tv,titleLayout);
        }
        scrollTo(0,0);
        this.invalidate();
    }


    private int dip2px(Context context, float dpValue) {
        if (context != null) {
            final float scale = context.getResources().getDisplayMetrics().density;
            return (int) (dpValue * scale + 0.5f);
        } else {
            return 0;
        }
    }

    private OnTouchLetterChangedListener listener;

    public OnTouchLetterChangedListener getListener() {
        return listener;
    }

    public void setListener(OnTouchLetterChangedListener listener) {
        this.listener = listener;
    }

    public interface OnTouchLetterChangedListener{
        public void onTouchLetterChanged(int index);
    }
}

https://github.com/weikaino1/MyHorizontalScrollView