Android 文本滚动效果的几种实现方式（二）
这一篇文章介绍了通过自定义surfaceview方法来实现通知滚动效果。这个方法的好处就是可以不受主线程影响，大家应该都知道Android所有绘制界面操作都是只允许在主线程中，但是surfaceview可以在子线程中绘制。为了避免主线程绘制工作量大出现卡顿现象，所以有了用surfaceview来实现滚动的念头。
通过自定义surfaceview实现滚动效果
这个方法比较简单，就是自定义一个surfaceview，通过SurfaceHolder获取画布来通过子线程不断绘制文字。直接上代码。
public class PlayNotifyInnerWindow extends SurfaceView implements SurfaceHolder.Callback {
/** * 初始化字体 */
public static Typeface addTypeface;
public static Typeface berTypeface;
public static Typeface daiTypeface;
public static Typeface dejTypeface;
public static Typeface droTypeface;
SurfaceHolder holder;
public PlayNotifyInnerWindow(Context context, int width, int height) {
super(context);
mContext = context;
// TODO Auto-generated constructor stub
rate = (((float) 1920) / ((float) 1080))
/ (((float) height) / ((float) width));
this.setLayoutParams(new LayoutParams(LayoutParams.MATCH_PARENT,
LayoutParams.WRAP_CONTENT));
holder = getHolder();
holder.addCallback(this); // 设置Surface生命周期回调
}
public void setPath(String path) {
this.setVisibility(View.VISIBLE);
paint = new Paint();
isStop = true;
i = 0;
currentScrollX = 0;
if (timer != null)
timer.cancel();
LayoutParams layoutParams = new LayoutParams(LayoutParams.MATCH_PARENT,
LayoutParams.WRAP_CONTENT);
layoutParams.addRule(RelativeLayout.ALIGN_PARENT_BOTTOM);
try {
filePath = path;
manager = getContext().getAssets();
String fileContent = readFile(path);//读取本地配置文件，json格式
JSONObject object = new JSONObject(fileContent);
content = object.getString("content") + " ";
left = object.getString("left");
right = object.getString("right");
mspeed = object.getString("speed");
bottom = object.getString("bottom");
cicrle = object.getString("cicrle");
isTran = object.getBoolean("isTransparent");
stopTime = object.getInt("stoptime");
isB = object.getBoolean("isBold");
isI = object.getBoolean("isItalic");
isU = object.getBoolean("isUnderline");
bgColor = object.getInt("bgColor");
bgZiti = object.getInt("bgFont");
zihao = object.getString("fontsize");
ziti = object.getString("font");
effect = object.getInt("effect");
if (!"".equals(left)) {
// layoutParams.leftMargin=Integer.parseInt(left);
layoutParams.setMargins(Integer.parseInt(left), 0, 0, 0);
}
if (!"".equals(right)) {
layoutParams.setMargins(0, 0, Integer.parseInt(right), 0);
}
if (!"".equals(left) && !"".equals(right)) {
layoutParams.setMargins(Integer.parseInt(left), 0,
Integer.parseInt(right), 0);
}
if (!"".equals(bottom)) {
layoutParams.bottomMargin = Integer.parseInt(bottom);
} else {
layoutParams.bottomMargin = 0;
}
msp = new SpannableString(content);
if (isB == true) {
paint.setFakeBoldText(true);
} else {
paint.setFakeBoldText(false);
}
if (isI == true) {
paint.setTextSkewX(-0.5f);
} else {
paint.setTextSkewX(0f);
}
if (isU == true) {
paint.setUnderlineText(true);
} else {
paint.setUnderlineText(false);
}
if (mspeed != null && !"".equals(mspeed)) {
speed = Integer.parseInt(mspeed);
} else {
speed = 5;
}
if (cicrle != null && !"".equals(cicrle)) {
cicle = Integer.parseInt(cicrle);
} else {
cicle = 10000;
}
if (bgZiti != 0) {
// 设置字体前景色
msp.setSpan(new ForegroundColorSpan(bgZiti), 0,
content.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); // 设置前景色为洋红色
} else {
msp.setSpan(new StyleSpan(android.graphics.Typeface.NORMAL), 0,
content.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE); // 正常
}
if (!"".equals(zihao)) {
fontSize = px2sp(mContext,
sp2px(mContext, Integer.parseInt(zihao)) * rate);
paint.setTextSize(fontSize);
} else {
fontSize = px2sp(mContext, sp2px(mContext, 24) * rate);
paint.setTextSize(fontSize);
}
if (!"".equals(ziti)) {
Typeface tf;
tf = choiceTypeface(ziti);// 根据路径得到Typeface
paint.setTypeface(tf);// 设置字体
} else {
msp.setSpan(new TypefaceSpan("monospace"), 0, content.length(),
Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
}
FontEffects mFontEffects = new FontEffects(paint, null);
mFontEffects.setFontEffects(effect);
i = 0;
this.setVisibility(View.VISIBLE);
isStop = false;
new Thread(new ScrollRunnable()).start();
this.setLayoutParams(layoutParams);
} catch (JSONException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
// 开始滚动
public void startScroll() {
Canvas c = null;
while (!isStop) {
currentScrollX += 10;// 滚动速度
synchronized (holder) {
paint.setColor(bgZiti);
c = holder.lockCanvas();
c.drawColor(bgColor); //重新绘制画布颜色，清空画布。
c.drawText(content, currentScrollX, 100, paint);//绘制文本，改变绘制位置
holder.unlockCanvasAndPost(c);
}
if (currentScrollX >= this.getWidth()) {
currentScrollX = 0;
// return;
if (i >= cicle) {
isStop = true;
} else {
i++;
}
}
}
}
class ScrollRunnable implements Runnable {
@Override
public void run() {
// TODO Auto-generated method stub
startScroll();
}
}
public void stopScroll() {
isStop = true;
this.setVisibility(View.GONE);
// scrollTo(0, 0);
// File file = new File(filePath);
// if (file.exists()) {
// file.delete();
// }
}
@Override
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
// TODO Auto-generated method stub
}
@Override
public void surfaceCreated(SurfaceHolder arg0) {
// TODO Auto-generated method stub
setPath("/mnt/external_sd/notify/notify_android.xml");
}
@Override
public void surfaceDestroyed(SurfaceHolder arg0) {
// TODO Auto-generated method stub
}