完成需求的时候涉及到这个所以撸了一下

本文章是本人原创，转载请带原地址连接

先放效果图('霁雪清虹"是目标)：

首先需要一个自定义HorizontalScrollView，复写一个View的onScrollChanged方法，用于监听滑动变化

代码如下：import android.content.Context;

import android.util.AttributeSet;

import android.widget.HorizontalScrollView;

/**

* Created by 霁雪清虹 on 2016/9/29.

*/

public class MyHorizontalScrollView extends HorizontalScrollView {

private MyScrollListener myScrollListener;

public MyHorizontalScrollView(Context context, AttributeSet attrs) {

super(context, attrs);

}

@Override

protected void onScrollChanged(int l, int t, int oldl, int oldt) {

super.onScrollChanged(l, t, oldl, oldt);

if (myScrollListener != null) {

myScrollListener.onScrollChanged();

}

}

public void setMyScrollListener(MyScrollListener myScrollListener) {

this.myScrollListener = myScrollListener;

}

public interface MyScrollListener {

void onScrollChanged();

}

}

然后就是MainActivity的onScrollChanged中的代码就是重点了

代码如下：

import android.graphics.Point;

import android.graphics.Rect;

import android.os.Bundle;

import android.support.v7.app.AppCompatActivity;

import android.util.Log;

import android.view.LayoutInflater;

import android.view.View;

import android.widget.LinearLayout;

import android.widget.RelativeLayout;

import android.widget.TextView;

import android.widget.Toast;

import java.util.ArrayList;

import java.util.List;

public class MainActivity extends AppCompatActivity implements View.OnClickListener, MyHorizontalScrollView.MyScrollListener {

protected TextView targetTextView;

private final static String NAME = "霁雪清虹";

protected MyHorizontalScrollView horizontalScrollView;

private Rect rect;

private Rect globalRect;

private Point globalOffset;

private List contentList = new ArrayList();

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

super.setContentView(R.layout.activity_main);

initView();

bindDataToUi();

rect = new Rect();

globalRect = new Rect();

globalOffset = new Point();

}

private void bindDataToUi() {

contentList.add("天涯");

contentList.add("兰亭书序");

contentList.add("天涯");

contentList.add("兰亭书序");

contentList.add("晨曦");

contentList.add("虹猫");

contentList.add("天涯");

contentList.add("兰亭书序");

contentList.add("霁雪清虹");

contentList.add("懵逼虹");

contentList.add("小逗比");

contentList.add("若冰");

contentList.add("晨曦");

contentList.add("虹猫");

contentList.add("天涯");

contentList.add("兰亭书序");

for (String str : contentList) {

RelativeLayout contentPanel = (RelativeLayout) LayoutInflater.from(this).inflate(R.layout.content, null);

((LinearLayout) horizontalScrollView.getChildAt(0)).addView(contentPanel);

TextView text = (TextView) contentPanel.findViewById(R.id.text);

if (NAME.equals(str)) {

targetTextView = text;

}

text.setText(str);

}

}

@Override

public void onClick(View view) {

}

private void initView() {

horizontalScrollView = (MyHorizontalScrollView) findViewById(R.id.horizontalScrollView);

horizontalScrollView.setMyScrollListener(this);

}

private boolean isFirstBack;

@Override

public void onBackPressed() {

if (isFirstBack) {

super.onBackPressed();

}

isFirstBack = true;

Toast.makeText(this, "再按一次退出程序", Toast.LENGTH_SHORT).show();

}

@Override

protected void onDestroy() {

super.onDestroy();

}

@Override

public void onScrollChanged() {

targetTextView.getGlobalVisibleRect(globalRect, globalOffset);

/* Log.e("TAG","globalRect is "+globalRect.toString());

Log.e("TAG","globalOffset is "+globalOffset.toString());

Log.e("TAG","reat width is "+reat.toString());*/

if (targetTextView.getLocalVisibleRect(rect)) {

//左可见

if (globalOffset.x < 0 && rect.width()< targetTextView.getWidth()

) {

Log.e("TAG", "目标霁雪清虹左半边可见");

} else if (globalOffset.x > 0 && rect.width() < targetTextView.getWidth()

) {

Log.e("TAG", "目标霁雪清虹右半边可见");

} else {

Log.e("TAG", "目标霁雪清虹全可见");

}

} else {

Log.e("TAG", "目标霁雪清虹不可见");

}

}

}

下面是Activity的xml

xmlns:android="http://schemas.android.com/apk/res/android"

xmlns:tools="http://schemas.android.com/tools"

android:id="@+id/activity_main"

android:layout_width="match_parent"

android:layout_height="match_parent"

android:paddingBottom="@dimen/activity_vertical_margin"

android:paddingLeft="@dimen/activity_horizontal_margin"

android:paddingRight="@dimen/activity_horizontal_margin"

android:paddingTop="@dimen/activity_vertical_margin"

tools:context="com.example.jiawei11.animationdemo.MainActivity">

android:id="@+id/horizontalScrollView"

android:layout_width="match_parent"

android:layout_height="wrap_content"

>

android:layout_width="match_parent"

android:layout_height="wrap_content"

android:paddingLeft="5dp"

android:paddingRight="5dp">

下面是 content.xml

android:layout_width="match_parent"

android:layout_height="match_parent"

android:paddingLeft="5dp"

android:paddingRight="5dp">

android:id="@+id/text"

android:layout_width="wrap_content"

android:layout_height="wrap_content"/>