又到了写博博的时候了！大家还好吧！
开始做机顶盒了，所以这里就有很多的界面需要做成一个自动化的界面。因为遥控盒手机触摸毕竟不一样咯！这里而且要方便大众的视觉体验的话，我们必须要考虑到这些因素。当然，我觉着，这次的自动滚动效果一定对大家也很有帮助的哦！
我们只要写一个类来继承我布局文件里面写的一个TextView就ok啦。
package com.example.myscroltextview.view;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.os.Message;
import android.util.AttributeSet;
import android.widget.TextView;/**
* 垂直滚动的textview
*
* @author Catherine.Brian.William
*
*/
public class VertailScrollTextView extends TextView {public VertailScrollTextView(Context context) {
super(context);
init();
}public VertailScrollTextView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}public VertailScrollTextView(Context context, AttributeSet attrs,
int defStyle) {
super(context, attrs, defStyle);
init();
}Handler handler;
/**
* 是否在滚动
*/
boolean scrolling = false;/**
* 当前的位移
*/
float currentY;
/**
* 每次滚动的距离
*/
float speed = 0.2f;/**
* 要显示的text
*/
String scrollText = "";/**
* 真实宽度,在配置width="xxdp"里起作用
*/
private int exactlyWidth = -1;/**
* 真实高度,在配置height="xxdip"里起作用
*/
private int exactlyHeight = -1;/**
* 实际高度：所有字显示完全需要的高度
*/
float absloutHeight = 0;/**
* handler发消息的时间间隔
*/
int delayTime = 50;/**
* 每行的字符串
*/
ArrayList<String> lineStrings;Paint mPaint;
private static final int DY = 20; // 每一行的间隔
/**
* 初始化
*/
private void init() {// 非高亮部分
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setTextSize(20);
mPaint.setColor(Color.WHITE);
mPaint.setTypeface(Typeface.SERIF);handler = new Handler() {
@Override
public void handleMessage(Message msg) {
if (absloutHeight <= getHeight()) {
currentY = 0;
stop();
return;
}
switch (msg.what) {
case 0:
currentY = currentY - speed;resetCurrentY();
invalidate();
handler.sendEmptyMessageDelayed(0, delayTime);
break;
}
super.handleMessage(msg);
}/**
* 重置currentY(当currentY超过absolutHeight时,让它重置为0)
*/
private void resetCurrentY() {
if (currentY >= absloutHeight || currentY <= -absloutHeight
|| getHeight() <= 0) {
currentY = 0;
}
}
};}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int width = MeasureWidth(widthMeasureSpec);
int height = MeasureHeight(width, heightMeasureSpec);
setMeasuredDimension(width, height);
currentY = 0;
if (height < absloutHeight) {
play();
} else {
stop();
}
}/**
* 测量宽度
*
* @param widthMeasureSpec
* @return
*/
private int MeasureWidth(int widthMeasureSpec) {
int mode = MeasureSpec.getMode(widthMeasureSpec);
int width = MeasureSpec.getSize(widthMeasureSpec);
// 如果时候wrap_content
if (mode == MeasureSpec.AT_MOST) {
double abwidth = getPaint().measureText(scrollText);
width = Math.min((int) Math.rint(abwidth), width);
exactlyWidth = -1;
}
// 精确宽度
if (mode == MeasureSpec.EXACTLY) {
exactlyWidth = width;
}
return width;}
/**
* 测量高度
*
* @param width
* @param heightMeasureSpec
* @return
*/
private int MeasureHeight(int width, int heightMeasureSpec) {
int mode = MeasureSpec.getMode(heightMeasureSpec);
int height = MeasureSpec.getSize(heightMeasureSpec);
generateTextList(width);int lines = lineStrings.size();
absloutHeight = lines * (getLineHeight() + DY) + getPaddingBottom()
+ getPaddingTop();
// 如果是wrap_content
if (mode == MeasureSpec.AT_MOST) {
height = (int) Math.min(absloutHeight, height);
exactlyHeight = -1;
} else if (mode == MeasureSpec.EXACTLY) {
exactlyHeight = height;
}return height;
}/**
* 生成多行字符串列表
*
* @param MaxWidth
*/
public void generateTextList(int MaxWidth) {
lineStrings = new ArrayList<String>();String remain = scrollText;
while (!remain.equals("")) {
String line = getLineText(MaxWidth, remain);
lineStrings.add(line);
remain = remain.substring(line.length(), remain.length());
}}
/**
* 获取一行的字符
*
* @param MaxWidth
* @param remain
* @return
*/
private String getLineText(int MaxWidth, String str) {// 真实行
StringBuffer trueStringBuffer = new StringBuffer();// 临时行
StringBuffer tempStringBuffer = new StringBuffer();for (int i = 0; i < str.length(); i++) {
char c = str.charAt(i);
String add = "";
if (!isChinese(c) && isENWordStart(str, i)) {
int place = getNextSpecePlace(i, str);
// 找到下一个空格
if (place > -1) {
add = str.substring(i, place) + " ";
if (getPaint().measureText(add) > MaxWidth) {
add = "" + c;
} else {
i = place;
}
} else {
add = "" + c;
}} else {
add = "" + c;
}
tempStringBuffer.append(add);
String temp = tempStringBuffer.toString();float width = getPaint().measureText(temp.toString());
if (width <= MaxWidth) {
trueStringBuffer.append(add);
} else {
break;
}}
return trueStringBuffer.toString();
}/**
* 找到下一个空格的地方
*
* @param i
* @param str
* @return
*/
int getNextSpecePlace(int i, String str) {for (int j = i; j < str.length(); j++) {
char c = str.charAt(j);
if (c == ‘ ‘) {return j;
}
}
return -1;
}/**
* 是否为英文单词的首字母
*
* @param str
* @param i
* @return
*/
boolean isENWordStart(String str, int i) {if (i == 0) {
return true;} else if (str.charAt(i - 1) == ‘ ‘) {
return true;
}
return false;
}/**
* 设置textview的文字
*
* @param scrollText
*/
public void setScrollText(String scrollText) {
this.scrollText = scrollText;
// setText(scrollText);
reset();
}public String getScrollText() {
return scrollText;
}/**
* 重置
*/
private void reset() {
requestLayout();
invalidate();
currentY = 0;
}/**
* 开始滚动
*/
public void play() {
if (!scrolling) {
handler.sendEmptyMessage(0);
scrolling = true;
}
}/**
* 停止滚动
*/
public void stop() {
if (scrolling) {
handler.removeMessages(0);
scrolling = false;
}
}/**
* 更改滚动状态
*/
public void updateScrollStatus() {
if (scrolling) {
stop();
} else {
play();
}
}@Override
protected void onDraw(Canvas canvas) {
// TODO Auto-generated method stub
super.onDraw(canvas);
float x = getPaddingLeft();
float y = getPaddingTop();float lineHeight = getLineHeight() + DY;
float textSize = getPaint().getTextSize();for (int i = 0; i < lineStrings.size(); i++) {
// currentY+=50;
y = lineHeight * i + textSize + currentY;float min = 0;
if (exactlyHeight > -1) {
min = Math.min(min, exactlyHeight - absloutHeight);
}
if (y < min) {
y = y + absloutHeight;
} else if (y >= min && y < textSize + min) {
// 如果最顶端的文字已经到达需要循环从下面滚出的时候
System.out.println("x:" + x + "y:" + y);
}
if (y >= absloutHeight) {
// 如果最底端的文字已经到达需要循环从上面滚出的时候
System.out.println("x:" + x + "y:" + y);
y = y - absloutHeight;
}canvas.drawText(lineStrings.get(i), x, y, mPaint);
}}
/**
* 判断是否为中文
*
* @param c
* @return
*/
private static final boolean isChinese(char c) {
Character.UnicodeBlock ub = Character.UnicodeBlock.of(c);
if (ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS
|| ub == Character.UnicodeBlock.CJK_COMPATIBILITY_IDEOGRAPHS
|| ub == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A
|| ub == Character.UnicodeBlock.GENERAL_PUNCTUATION
|| ub == Character.UnicodeBlock.CJK_SYMBOLS_AND_PUNCTUATION
|| ub == Character.UnicodeBlock.HALFWIDTH_AND_FULLWIDTH_FORMS) {
return true;
}
return false;
}}
自动滚动的Textview