重写HorizontalScrollView实现代码控制水平滚动定位

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重写HorizontalScrollView实现代码控制水平滚动定位
CenterShowHorizontalScrollView.java

package com.aldx.hccraftsman.view;import android.content.Context;import android.util.AttributeSet;import android.view.Gravity;import android.view.View;import android.widget.HorizontalScrollView;import android.widget.LinearLayout;import com.aldx.hccraftsman.R;import com.aldx.hccraftsman.utils.Utils;/** * author: chenzheng * created on: 2017/5/10 16:26 * description: */public class CenterShowHorizontalScrollView extends HorizontalScrollView {    private LinearLayout mShowLinear;    private Context context;    public CenterShowHorizontalScrollView(Context context, AttributeSet attrs) {        super(context, attrs);        this.context = context;        mShowLinear = new LinearLayout(context);        mShowLinear.setOrientation(LinearLayout.HORIZONTAL);        HorizontalScrollView.LayoutParams params = new HorizontalScrollView.LayoutParams(                LayoutParams.WRAP_CONTENT, LayoutParams.MATCH_PARENT);        mShowLinear.setGravity(Gravity.CENTER_VERTICAL);        this.addView(mShowLinear, params);    }    public void onClicked(View v) {        if (v.getTag(R.id.item_position) != null) {            int position = (Integer) v.getTag(R.id.item_position);            View itemView = mShowLinear.getChildAt(position);            int itemWidth = itemView.getWidth();            int screenWidth = Utils.getScreenW(context);            smoothScrollTo(itemView.getLeft() - (screenWidth / 2 - itemWidth / 2), 0);        }    }    public void onClicked(int position) {        View itemView = mShowLinear.getChildAt(position);        int itemWidth = itemView.getWidth();        int screenWidth = Utils.getScreenW(context);        smoothScrollTo(itemView.getLeft() - (screenWidth / 2 - itemWidth / 2), 0);    }    public LinearLayout getLinear() {        return mShowLinear;    }    public void addItemView(View itemView, int position) {        itemView.setTag(R.id.item_position, position);        mShowLinear.addView(itemView);    }}

<com.aldx.hccraftsman.view.CenterShowHorizontalScrollView        android:id="@+id/tab_horizontalscrollView"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:background="#e5e5e5"        android:scrollbars="none" />

CenterShowHorizontalScrollView内部已经添加过LinearLayout所以不需要再重复添加了，直接将子view添加进去即可：

mHScrollView.addItemView(itemView, i);

代码控制滚动定位：

mHScrollView.onClicked(view);

或

mHScrollView.onClicked(position);

注:
如果你再oncreate方法里就想调用滚动定位，是看不到效果的，因为这时控件的宽度还没有被测量出来，解决方法：

mHScrollView.getViewTreeObserver().addOnGlobalLayoutListener(                new ViewTreeObserver.OnGlobalLayoutListener() {                    @Override                    public void onGlobalLayout() {                        if(tempViewList.size()>0) {                            mHScrollView.onClicked(temp_tab);                        }                        mHScrollView.getViewTreeObserver()                                .removeGlobalOnLayoutListener(this);                    }                });

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