android TextView向上滚动（模仿滚动文字广告效果）

android文字向上滚动效果没有自带的控件，这就需要开发者根据算法精确按照时间和坐标来实现TextView控件的向上移动，从网上找过几个框架，基本都会有bug，于是自己写了一个自定义控件，来实现TextView平滑向上滚动的文字效果

首先，自定义控件：ScrollBanner.java

public class ScrollBanner extends LinearLayout {
private TextView mBannerTV1;
private TextView mBannerTV2;
private Handler handler;
private boolean isShow=false;
private int startY1, endY1, startY2, endY2;
private Runnable runnable;
private List<String> list;
private int position = 0;
private int offsetY = 100;
public ScrollBanner(Context context) {
this(context, null);
}

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

public ScrollBanner(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
View view = LayoutInflater.from(context).inflate(R.layout.view_scroll_banner, this);
mBannerTV1 = (TextView) view.findViewById(R.id.tv_banner1);
mBannerTV2 = (TextView) view.findViewById(R.id.tv_banner2);
handler = new Handler();
runnable = new Runnable() {
@Override
public void run() {
isShow = !isShow;
if (position == list.size()-1) {
position = 0;
}
if (isShow) {
mBannerTV1.setText(list.get(position++));
mBannerTV2.setText(list.get(position));
} else {
mBannerTV2.setText(list.get(position++));
mBannerTV1.setText(list.get(position));
}
startY1 = isShow ? 0 : offsetY;
endY1 = isShow ? -offsetY : 0;
ObjectAnimator.ofFloat(mBannerTV1, "translationY", startY1, endY1).setDuration(300).start();
startY2 = isShow ? offsetY : 0;
endY2 = isShow ? 0 : -offsetY;
ObjectAnimator.ofFloat(mBannerTV2, "translationY", startY2, endY2).setDuration(300).start();
handler.postDelayed(runnable, 3000);
}
};
}
public List<String> getList() {
return list;
}
public void setList(List<String> list) {
this.list = list;
}
public void startScroll() {
handler.post(runnable);
}
public void stopScroll() {
handler.removeCallbacks(runnable);
}
}

布局文件 view_scroll_banner.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:paddingLeft="10dp"
android:paddingTop="5dp"
android:paddingBottom="5dp">

<TextView
android:id="@+id/tv_banner1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:ellipsize="end"
android:singleLine="true"
android:textColor="#FFFF7B00"
android:textSize="11sp"
/>

<TextView
android:id="@+id/tv_banner2"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:ellipsize="end"
android:singleLine="true"
android:textColor="#FFFF7B00"
android:textSize="11sp"
/>
</RelativeLayout>

主界面布局引用如下控件：

<com.example.view.ScrollBanner
android:id="@+id/sb_demographic"
android:layout_width="match_parent"
android:layout_height="wrap_content"
/>

在将要实现该效果的页面调用以下方法即可

ScrollBanner sb_demographic;
sb_demographic = (ScrollBanner) rootView.findViewById(R.id.sb_demographic);
List<String> demographicsList=new ArrayList<String>();
for(int i=0;i<20;i++){
demographicsList.add("第"+i+"条内容");
}
sb_demographic.setList(demographicsList);
sb_demographic.startScroll();