Android 实现公告上下滚动效果？

1.自定义View

MarqueeTextView

package com.ruidde.jz.utils;

import android.content.Context;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.View;
import android.view.animation.AnimationUtils;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.ViewFlipper;

import com.ruidde.jz.R;
import com.ruidde.jz.model.entity.Notice;

import java.util.List;

public class MarqueeTextView extends LinearLayout {

    private List<Notice> noticeList;
    private Context mContext;
    private ViewFlipper viewFlipper;
    private View marqueeTextView;

    public MarqueeTextView(Context context) {
        super(context);
        mContext = context;
        initBasicView();
    }


    public MarqueeTextView(Context context, AttributeSet attrs) {
        super(context, attrs);
        mContext = context;
        initBasicView();
    }

    public void setTextArraysAndClickListener(List<Notice> noticeList) {//1.设置数据源；2.设置监听回调（将textView点击事件传递到目标界面进行操作）
        this.noticeList = noticeList;
        initMarqueeTextView(noticeList);
    }

    public void initBasicView() {//加载布局，初始化ViewFlipper组件及效果
        marqueeTextView = LayoutInflater.from(mContext).inflate(R.layout.marquee_textview_layout, null);
        LayoutParams layoutParams = new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
        addView(marqueeTextView, layoutParams);
        viewFlipper = (ViewFlipper) marqueeTextView.findViewById(R.id.viewFlipper);
        viewFlipper.setInAnimation(AnimationUtils.loadAnimation(mContext, R.anim.slide_in_bottom));//设置上下的动画效果（自定义动画，所以改左右也很简单）
        viewFlipper.setOutAnimation(AnimationUtils.loadAnimation(mContext, R.anim.slide_out_top));
        viewFlipper.startFlipping();
    }

    public void initMarqueeTextView(List<Notice> noticeList) {
        if (noticeList.size() == 0) {
            return;
        }

        int i = 0;
        viewFlipper.removeAllViews();
        for (int j = 0; j < noticeList.size(); j++) {
            Notice notice = noticeList.get(j);
            TextView textView = new TextView(mContext);
            textView.setSingleLine(true);
            textView.setEllipsize(TextUtils.TruncateAt.END);
            textView.setTextSize(14);
            textView.setTextColor(getResources().getColor(R.color.marqueecolor));
            textView.setText(notice.getNoticeTitle());
            textView.setOnClickListener(new OnClickListener() {
                @Override
                public void onClick(View v) {
                    itemOnClickListener.onItemClick(notice);
                }
            });
            LayoutParams lp = new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
            viewFlipper.addView(textView, lp);
        }
    }

    public void releaseResources() {
        if (marqueeTextView != null) {
            if (viewFlipper != null) {
                viewFlipper.stopFlipping();
                viewFlipper.removeAllViews();
                viewFlipper = null;
            }
            marqueeTextView = null;
        }
    }

    public ExamineClickLisitenner itemOnClickListener;

    public interface ExamineClickLisitenner {
        void onItemClick(Notice notice);
    }

    public void setItemOnClickListener(ExamineClickLisitenner itemOnClickListener) {
        this.itemOnClickListener = itemOnClickListener;
    }
}

（1）.其中layout：marquee_textview_layout

<?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="wrap_content"
    android:background="@color/transparent"
    android:orientation="horizontal">

    <ViewFlipper
        android:id="@+id/viewFlipper"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:flipInterval="3000">
    </ViewFlipper>
</LinearLayout>

（2）.动画效果

slide_in_bottom

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <translate
        android:duration="@android:integer/config_mediumAnimTime"
        android:fromYDelta="50%p"
        android:toYDelta="0" />
    <alpha
        android:duration="@android:integer/config_mediumAnimTime"
        android:fromAlpha="0.0"
        android:toAlpha="1.0" />
</set>

slide_out_top

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <translate
        android:duration="@android:integer/config_mediumAnimTime"
        android:fromYDelta="0"
        android:toYDelta="-50%p" />
    <alpha
        android:duration="@android:integer/config_mediumAnimTime"
        android:fromAlpha="1.0"
        android:toAlpha="0.0" />
</set>

3.XML使用

<com.ruidde.jz.utils.MarqueeTextView
    android:id="@+id/tv_content"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_centerVertical="true"
    android:layout_marginStart="9dp"
    android:layout_marginEnd="2dp"
    android:layout_toEndOf="@+id/tv_gonggaoT"
    android:layout_toStartOf="@+id/tv_List"/>

4.activity中使用

lateinit var noticeList: List<Notice>

tv_content.setTextArraysAndClickListener(noticeList)
tv_content.setItemOnClickListener(object : MarqueeTextView.ExamineClickLisitenner { override fun onItemClick(notice: Notice) { TongZhiDetailsActivity.stattTongZhiDetailsActivity(mContext, notice) } })

手工……