1. 准备 txt文件

txt.png

2. 工具类

/**
 * Created on 2021/3/18 9:53
 *
 * @author Gong Youqiang
 */
public class Utils {
    private static final String TAG = "Utils";
    /**
     * 获取文件
     * @return
     */
    public static String getFileContent(String filePath ,String fileName) {
        String content = "";
        String path = filePath + fileName;
        File file = new File(path);
        try {
            InputStream inputStream = new FileInputStream(file);
            if (inputStream != null){
                InputStreamReader reader = new InputStreamReader(inputStream,"GB2312");
                BufferedReader bufferedReader = new BufferedReader(reader);

                String line;
                while ((line = bufferedReader.readLine()) != null){
                    content += line + "\n";
                }
                inputStream.close();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        Log.d(TAG, "getFileContent: content = " + content);
        return content;
    }


    /**
     * 获取raw文件夹下的文件内容
     * @param context
     * @return
     */
    public static String getRawTxtFileContent(Context context,int rawResId) {
        String content = "";
        try {
            InputStream inputStream = context.getResources().openRawResource(rawResId);
            if (inputStream != null){
                InputStreamReader reader = new InputStreamReader(inputStream,"GB2312");
                BufferedReader bufferedReader = new BufferedReader(reader);

                String line;
                while ((line = bufferedReader.readLine()) != null){
                    content += line + "\n";
                }
                inputStream.close();
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        Log.d(TAG, "getFileContent: content = " + content);
        return content;
    }


    public static String getVersionInfo(Context context) {
        PackageManager pm = context.getPackageManager();
        String versionInfo = "";
        try {
            PackageInfo info = pm.getPackageInfo(context.getPackageName(),0);
            versionInfo = info.versionName;
        } catch (PackageManager.NameNotFoundException e) {
            e.printStackTrace();
        }
        return versionInfo;
    }
}

3. AutoScrollView.java

public class AutoScrollView extends ScrollView {
    private static final String TAG = "AutoScrollView";
    private static final int MSA_SCROLL = 1;
    private int mPaddingTop = 0;

    /**
     * 每次滚动的像素点数
     */
    private float mScrollPixelNums = 0.0f;
    /**
     * 刷新的时间间隔
     */
    private int mScrollTimeInterval;
    private int mHeight;


    public AutoScrollView(Context context) {
        this(context,null);
        Log.d(TAG, "AutoScrollView: 1");
    }


    public AutoScrollView(Context context, AttributeSet attrs) {
        this(context, attrs,0);
        Log.d(TAG, "AutoScrollView: 2");
    }

    public AutoScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr,0);
        Log.d(TAG, "AutoScrollView: 3");

    }




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

        mHeight = getChildAt(0).getHeight();
        //计算刷新时间 ：单位（像素）时间(ms) 高度（像素）

        //刷新时间 =  高度 /

        Log.d(TAG, "onLayout: height = " + mHeight);
    }

    private Handler mHandler = new Handler(){
        @Override
        public void handleMessage(@NonNull Message msg) {
            super.handleMessage(msg);
            Log.d(TAG, "handleMessage: msg.what = " + msg.what);

            switch (msg.what){
                case MSA_SCROLL:
                    //假如mPaddingTop等于scrollview，停止执行handler
                    if (mPaddingTop <= mHeight){
                        scrollTo(0,mPaddingTop);
                        mPaddingTop += mScrollPixelNums;
                        mHandler.removeMessages(MSA_SCROLL);
                        mHandler.sendEmptyMessageDelayed(MSA_SCROLL,mScrollTimeInterval);
                    }

                    break;
            }
        }
    };


    /**
     * 开始滚动
     * @param scrollPixelNums 每次滚动的像素点数量
     * @param scrollTimeInterval 每次滚动的时间间隔
     */
    public void startScroll(float scrollPixelNums,int scrollTimeInterval){
        mScrollPixelNums = scrollPixelNums;
        mScrollTimeInterval = scrollTimeInterval;
        mHandler.sendEmptyMessageDelayed(MSA_SCROLL,mScrollTimeInterval);
    }


    public void stopScroll() {
        mHandler.removeMessages(MSA_SCROLL);
    }
}

activity_main.xml

<?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="match_parent"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:orientation="vertical">

    <com.hk.zxingtest.view.AutoScrollView
        android:id="@+id/auto_scrollview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:background="@android:color/white"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/layout_1">
        <TextView
            android:id="@+id/tv_content"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:layout_marginLeft="32dp"
            android:layout_marginRight="28dp"
            android:layout_marginTop="28dp"
            android:layout_marginBottom="31dp"
            />
    </com.hk.zxingtest.view.AutoScrollView>

</LinearLayout>

MainActivity.java

public class MainActivity extends AppCompatActivity {

    @BindView(R.id.auto_scrollview)
    AutoScrollView mAutoScrollView;
    @BindView(R.id.tv_content)
    TextView mTvContent;

    private String mContent;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);
        initData();
    }

    private void initData() {
        mContent = Utils.getRawTxtFileContent(this,R.raw.rlxz);
        mTvContent.setText(mContent);
        mAutoScrollView.startScroll(1.0f,50);
    }
}