可以修改Laya的Layout类：
函数_multiLineLayout
```
//生成排版的行
for (i = 0; i < n; i++) {
oneLayout = elements[i];
if (oneLayout == null) {
if (!tLineFirstKey) {
x += Layout.DIV_ELEMENT_PADDING;
}
curLine.wordStartIndex = curLine.elements.length;
continue;
}
tLineFirstKey = false;
if (oneLayout instanceof IHtml.HTMLBrElement) {
addLine();
curLine.y = y;
curLine.h = lineHeight;
continue;
} else if (oneLayout._isChar()) {
htmlWord = <HTMLChar>oneLayout;
w = htmlWord.width + htmlWord.style.letterSpacing; // 下面要用到w，所以先计算（Bug:英文的宽度按照前面的汉字的宽度计算导致错误换行）
h = htmlWord.height;
if (!htmlWord.isWord) //如果是完整单词
{
if (lines.length > 0 && (x + w) > width && curLine.wordStartIndex > 0) //如果完整单词超界，需要单词开始折到下一行
{
var tLineWord: number = 0;
tLineWord = curLine.elements.length - curLine.wordStartIndex + 1;
curLine.elements.length = curLine.wordStartIndex;
i -= tLineWord;
addLine();
continue;
}
newLine = false;
tWordWidth += htmlWord.width;
} else {
newLine = nextNewline || (htmlWord.char === '\n');
curLine.wordStartIndex = curLine.elements.length;
}
nextNewline = false;
newLine = newLine || ((x + w) > width);
newLine && addLine();
curLine.minTextHeight = Math.min(curLine.minTextHeight, oneLayout.height);
} else {
curStyle = oneLayout._getCSSStyle();
sprite = (<HTMLElement>oneLayout);
curPadding = curStyle.padding;
//curStyle._getCssFloat() === 0 || (endAdjust = true);
newLine = nextNewline || curStyle.getLineElement();
w = sprite.width + curPadding[1] + curPadding[3] + curStyle.letterSpacing;
h = sprite.height + curPadding[0] + curPadding[2];
nextNewline = curStyle.getLineElement();
newLine = newLine || ((x + w) > width && curStyle.wordWrap);
newLine && addLine();
}
curLine.elements.push(oneLayout);
curLine.h = Math.max(curLine.h, h);//计算最大宽和高
oneLayout.x = x;
/////------------------------------------------------------
///此处的xxx是个自定义变量，用于偏移Y坐标使用，例如：可以设置图片往上偏移a，这样图片就可以居中显示了
///`<img width='40' height='40' sy='a' src='url'></img>`
oneLayout.y = y + Number(oneLayout["[size=14]sy[/size]"] || 0);
////--------------------------------------------------
x += w;
curLine.w = x - letterSpacing;
curLine.y = y;
maxWidth = Math.max(x + exWidth, maxWidth);
}
```
