android 垂直滚动的TextView

package com.test; import java.util.ArrayList; import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Typeface; import android.os.Handler; import android.util.AttributeSet; import android.widget.TextView; public class VerticalScrollTextView extends TextView { private int index; private float mX,mY,middleY,DY; private Paint mPaint,mPathPaint; private ArrayList<Sentence> list; public VerticalScrollTextView(Context context) { super(context); init(); } public VerticalScrollTextView(Context context, AttributeSet attrs) { super(context, attrs); init(); } public VerticalScrollTextView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); init(); } private void init() { setFocusable(true); //这里主要处理如果没有传入内容显示的默认值 if(list==null){ list=new ArrayList<Sentence>(); Sentence sen=new Sentence(0,"暂时没有通知公告"); list.add(0, sen); } //普通文字的字号，以及画笔颜色的设置 mPaint = new Paint(); mPaint.setAntiAlias(true); mPaint.setTextSize(16); mPaint.setColor(Color.BLACK); mPaint.setTypeface(Typeface.SERIF); //高亮文字的字号，以及画笔颜色的设置 mPathPaint = new Paint(); mPathPaint.setAntiAlias(true); mPathPaint.setColor(Color.RED); mPathPaint.setTextSize(16); mPathPaint.setTypeface(Typeface.SANS_SERIF); } @Override protected void onDraw(Canvas canvas) { super.onDraw(canvas); canvas.drawColor(0xEFeffff); Paint p = mPaint; Paint p2 = mPathPaint; p.setTextAlign(Paint.Align.CENTER); if (index == -1) return; p2.setTextAlign(Paint.Align.CENTER); canvas.drawText(list.get(index).getTitle(), mX, middleY, p2); DY=p.getTextSize()*2; float tempY = middleY; for (int i = index - 1; i >= 0; i--) { tempY = tempY - DY; if (tempY < 0) { break; } canvas.drawText(list.get(i).getTitle(), mX, tempY, p); } tempY = middleY; for (int i = index + 1; i < list.size(); i++) { tempY = tempY + DY; if (tempY > mY) { break; } canvas.drawText(list.get(i).getTitle(), mX, tempY, p); } } @Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh); mX = w * 0.5f; mY = h; middleY = h * 0.5f; } private long updateIndex(int index) { if (index == -1) return -1; this.index=index; return index; } public void updateUI(){ new Thread(new updateThread()).start(); } class updateThread implements Runnable { long time = 1000; int i=0; public void run() { while (true) { long sleeptime = updateIndex(i); time += sleeptime; mHandler.post(mUpdateResults); if (sleeptime == -1) return; try { Thread.sleep(time); i++; if(i==list.size()) i=0; } catch (InterruptedException e) { e.printStackTrace(); } } } } Handler mHandler = new Handler(); Runnable mUpdateResults = new Runnable() { public void run() { invalidate(); } }; public void setList(ArrayList<Sentence> list) { this.list = list; } }