先看下效果图：
上面是MTextView，下面是默认的TextView。
一、原因
用最简单的全英文句子为例，如果有一个很长的单词，这一行剩余的空间显示不下了，那么规则就是不打断单词，而是把整个单词丢到下一行开始显示。这样本来没有错。一是咱们中国人都是方块字，怎么都放得下，不存在英文的这个问题。所以不习惯那个排版。二是如果TextView里面有图片，如图，
不知道判断单词的代码是怎么弄得，总之它觉得最后一个啦字和后面的一串表情应该是一个整体，不能分开，就一起丢到第二行了，也就造成了这种难看的排版。要验证这个说法也很简单，自己去QQ里试一试，在每个表情之间都加一个空格，就会发现排版一下子正常了。
二、解决方法
最简单的就是表情之间加空格，如果不想这么做，就只有自己来画啦。
先给初学的朋友解释一下View绘制的流程，首先是onMeasure(int widthMeasureSpec, int heightMeasureSpec),onMeasure执行的时候，就是父View在问你，小朋友，你要占多大的地儿呀？当然，问你的时候，会给你个限制条件，就是那两参数，以widthMeasureSpec为例，这参数不能直接用，得先拆开，用int widthMode = MeasureSpec.getMode(widthMeasureSpec) 和 int widthSize =
MeasureSpec.getSize(widthMeasureSpec);widthMode就三种情况：
MeasureSpec.EXACTLY：你就widthSize那么宽就行了。
MeasureSpec.AT_MOST：你最多只能widthSize那么宽。
MeasureSpec.UNSPECIFIED：未指定，你爱多宽多宽。
当然，其实这只父View给你的建议，遵不遵守你自己看着办，但是自己乱来导致显示不全就不是父View的错了。
最终你听取了建议，思量了一番，觉得自己应该有width那么宽，height那么高，最后就得用setMeasuredDimension(width, height)这个函数真正确定自己的高宽。然后onMeasure()的工作就完了。
然后就是onDraw(Canvas canvas)，这个就简单了，canvas就是父View给的一块画布，爱在上面画啥都行，比如写个字drawText(String text,float
x, float y,
Paint paint)，
text是要写的字，paint是写字的笔，值得注意的是x,y坐标是相对于你自己这一小块画布的左上角的。最左上就是0,0右下是width,height
上代码
/**
* @功能 图文混排TextView，请使用{@link #setMText(CharSequence)}
* @author huangwei
* @2014年5月27日
* @下午5:29:27
*/
public class MTextView extends TextView
{
private Context context;
/**
* 用于测量字符宽度
*/
private Paint paint = new Paint();
private int textColor = Color.BLACK;
//行距
private float lineSpacing;
private int lineSpacingDP = 2;
// private float lineSpacingMult = 0.5f;
/**
* 最大宽度
*/
private int maxWidth;
/**
* 只有一行时的宽度
*/
private int oneLineWidth = -1;
/**
* 已绘的行中最宽的一行的宽度
*/
private float lineWidthMax = -1;
/**
* 存储当前文本内容,每个item为一个字符或者一个ImageSpan
*/
private ArrayList<Object> obList = new ArrayList<Object>();
/**
* 是否使用默认{@link #onMeasure(int, int)}和{@link #onDraw(Canvas)}
*/
private boolean useDefault = false;
/**
* 存储当前文本内容，每个item为一行
*/
ArrayList<LINE> contentList = new ArrayList<LINE>();
/**
* 缓存测量过的数据
*/
private static HashMap<String, SoftReference<MeasuredData>> measuredData = new HashMap<String, SoftReference<MeasuredData>>();
private static int hashIndex = 0;
private CharSequence text = "";
/**
* 最小高度
*/
private int minHeight;
/**
* 用以获取屏幕高宽
*/
private DisplayMetrics displayMetrics;
public MTextView(Context context)
{
super(context);
this.context = context;
paint.setAntiAlias(true);
lineSpacing = dip2px(context, lineSpacingDP);
minHeight = dip2px(context, 30);
displayMetrics = new DisplayMetrics();
}
public MTextView(Context context, AttributeSet attrs)
{
super(context, attrs);
this.context = context;
paint.setAntiAlias(true);
lineSpacing = dip2px(context, lineSpacingDP);
minHeight = dip2px(context, 30);
displayMetrics = new DisplayMetrics();
}
@Override
public void setMaxWidth(int maxpixels)
{
super.setMaxWidth(maxpixels);
maxWidth = maxpixels;
}
@Override
public void setMinHeight(int minHeight)
{
super.setMinHeight(minHeight);
this.minHeight = minHeight;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
if (useDefault)
{
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
return;
}
int width = 0, height = 0;
int widthMode = MeasureSpec.getMode(widthMeasureSpec);
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
int widthSize = MeasureSpec.getSize(widthMeasureSpec);
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
switch (widthMode)
{
case MeasureSpec.EXACTLY:
width = widthSize;
break;
case MeasureSpec.AT_MOST:
width = widthSize;
break;
case MeasureSpec.UNSPECIFIED:
((Activity) context).getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
width = displayMetrics.widthPixels;
break;
default:
break;
}
if (maxWidth > 0)
width = Math.min(width, maxWidth);
paint.setTextSize(this.getTextSize());
paint.setColor(textColor);
int realHeight = measureContentHeight((int) width);
//如果实际行宽少于预定的宽度，减少行宽以使其内容横向居中
int leftPadding = getCompoundPaddingLeft();
int rightPadding = getCompoundPaddingRight();
width = Math.min(width, (int) lineWidthMax + leftPadding+ rightPadding);
if (oneLineWidth > -1)
{
width = oneLineWidth;
}
switch (heightMode)
{
case MeasureSpec.EXACTLY:
height = heightSize;
break;
case MeasureSpec.AT_MOST:
height = realHeight;
break;
case MeasureSpec.UNSPECIFIED:
height = realHeight;
break;
default:
break;
}
height += getCompoundPaddingTop() + getCompoundPaddingBottom();
height = Math.max(height,minHeight);
setMeasuredDimension(width, height);
}
@Override
protected void onDraw(Canvas canvas)
{
if (useDefault)
{
super.onDraw(canvas);
return;
}
int width;
Object ob;
int leftPadding = getCompoundPaddingLeft();
int topPadding = getCompoundPaddingTop();
float height = 0 + topPadding + lineSpacing;
//只有一行时
if(oneLineWidth != -1)
{
height = getMeasuredHeight() /2 - contentList.get(0).height/2;
}
for (int i = 0; i < contentList.size(); i++)
{
//绘制一行
float realDrawedWidth = 0 + leftPadding;
LINE line = contentList.get(i);
for (int j = 0; j < line.line.size(); j++)
{
ob = line.line.get(j);
width = line.widthList.get(j);
if (ob instanceof String)
{
canvas.drawText((String) ob, realDrawedWidth, height + line.height, paint);
realDrawedWidth += width;
}
else if (ob instanceof ImageSpan)
{
ImageSpan is = (ImageSpan) ob;
Drawable d = is.getDrawable();
int left = (int) (realDrawedWidth);
int top = (int) height;
int right = (int) (realDrawedWidth + width);
int bottom = (int) (height + line.height);
d.setBounds(left, top, right, bottom);
d.draw(canvas);
realDrawedWidth += width;
}
}
height += line.height + lineSpacing;
}
}
@Override
public void setTextColor(int color)
{
super.setTextColor(color);
textColor = color;
}
/**
* 用于带ImageSpan的文本内容所占高度测量
* @param width 预定的宽度
* @return 所需的高度
*/
private int measureContentHeight(int width)
{
int cachedHeight = getCachedData(text.toString(), width);
if(cachedHeight > 0)
{
return cachedHeight;
}
// 已绘的宽度
float obWidth = 0;
float obHeight = 0;
float textSize = this.getTextSize();
//行高
float lineHeight = textSize;
//计算出的所需高度
float height = lineSpacing;
int leftPadding = getCompoundPaddingLeft();
int rightPadding = getCompoundPaddingRight();
float drawedWidth = 0;
width = width - leftPadding - rightPadding;
oneLineWidth = -1;
contentList.clear();
StringBuilder sb;
LINE line = new LINE();
for (int i = 0; i < obList.size(); i++)
{
Object ob = obList.get(i);
if (ob instanceof String)
{
obWidth = paint.measureText((String) ob);
obHeight = textSize;
}
else if (ob instanceof ImageSpan)
{
Rect r = ((ImageSpan) ob).getDrawable().getBounds();
obWidth = r.right - r.left;
obHeight = r.bottom - r.top;
if (obHeight > lineHeight)
lineHeight = obHeight;
}
//这一行满了，存入contentList,新起一行
if (width - drawedWidth < obWidth)
{
contentList.add(line);
if (drawedWidth > lineWidthMax)
{
lineWidthMax = drawedWidth;
}
drawedWidth = 0;
height += line.height + lineSpacing;
lineHeight = obHeight;
line = new LINE();
}
drawedWidth += obWidth;
if (ob instanceof String && line.line.size() > 0 && (line.line.get(line.line.size() - 1) instanceof String))
{
int size = line.line.size();
sb = new StringBuilder();
sb.append(line.line.get(size - 1));
sb.append(ob);
ob = sb.toString();
obWidth = obWidth + line.widthList.get(size - 1);
line.line.set(size - 1, ob);
line.widthList.set(size - 1, (int) obWidth);
line.height = (int) lineHeight;
}
else
{
line.line.add(ob);
line.widthList.add((int) obWidth);
line.height = (int) lineHeight;
}
}
if (line != null && line.line.size() > 0)
{
contentList.add(line);
height += lineHeight + lineSpacing;
}
if (contentList.size() <= 1)
{
oneLineWidth = (int) drawedWidth + leftPadding + rightPadding;
height = lineSpacing + lineHeight + lineSpacing;
}
cacheData(width,(int) height);
return (int) height;
}
/**
* 获取缓存的测量数据，避免多次重复测量
* @param text
* @param width
* @return height
*/
@SuppressWarnings("unchecked")
private int getCachedData(String text, int width)
{
SoftReference<MeasuredData> cache = measuredData.get(text);
if(cache == null)
return -1;
MeasuredData md = cache.get();
if (md != null && md.textSize == this.getTextSize() && width == md.width)
{
lineWidthMax = md.lineWidthMax;
contentList = (ArrayList<LINE>) md.contentList.clone();
oneLineWidth = md.oneLineWidth;
StringBuilder sb = new StringBuilder();
for(int i=0;i<contentList.size();i++)
{
LINE line = contentList.get(i);
sb.append(line.toString());
}
return md.measuredHeight;
}
else
return -1;
}
/**
* 缓存已测量的数据
* @param width
* @param height
*/
@SuppressWarnings("unchecked")
private void cacheData(int width, int height)
{
MeasuredData md = new MeasuredData();
md.contentList = (ArrayList<LINE>) contentList.clone();
md.textSize = this.getTextSize();
md.lineWidthMax = lineWidthMax;
md.oneLineWidth = oneLineWidth;
md.measuredHeight = height;
md.width = width;
md.hashIndex = ++hashIndex;
StringBuilder sb = new StringBuilder();
for(int i=0;i<contentList.size();i++)
{
LINE line = contentList.get(i);
sb.append(line.toString());
}
SoftReference<MeasuredData> cache = new SoftReference<MeasuredData>(md);
measuredData.put(text.toString(),cache);
}
/**
* 用本函数代替{@link #setText(CharSequence)}
* @param cs
*/
public void setMText(CharSequence cs)
{
text = cs;
obList.clear();
// contentList.clear();
ArrayList<IS> isList = new ArrayList<MTextView.IS>();
useDefault = false;
if (cs instanceof SpannableString)
{
SpannableString ss = (SpannableString) cs;
ImageSpan[] imageSpans = ss.getSpans(0, ss.length(), ImageSpan.class);
for (int i = 0; i < imageSpans.length; i++)
{
int s = ss.getSpanStart(imageSpans[i]);
int e = ss.getSpanEnd(imageSpans[i]);
IS iS = new IS();
iS.is = imageSpans[i];
iS.start = s;
iS.end = e;
isList.add(iS);
}
}
String str = cs.toString();
for (int i = 0, j = 0; i < cs.length();)
{
if (j < isList.size())
{
IS is = isList.get(j);
if (i < is.start)
{
Integer cp = str.codePointAt(i);
//支持增补字符
if (Character.isSupplementaryCodePoint(cp))
{
i += 2;
}
else
{
i++;
}
obList.add(new String(Character.toChars(cp)));
}
else if (i >= is.start)
{
obList.add(is.is);
j++;
i = is.end;
}
}
else
{
Integer cp = str.codePointAt(i);
if (Character.isSupplementaryCodePoint(cp))
{
i += 2;
}
else
{
i++;
}
obList.add(new String(Character.toChars(cp)));
}
}
requestLayout();
}
public void setUseDefault(boolean useDefault)
{
this.useDefault = useDefault;
if (useDefault)
{
this.setText(text);
this.setTextColor(textColor);
}
}
public static int px2sp(Context context, float pxValue)
{
final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;
return (int) (pxValue / fontScale + 0.5f);
}
/**
* 根据手机的分辨率从 dp 的单位 转成为 px(像素)
*/
public static int dip2px(Context context, float dpValue)
{
final float scale = context.getResources().getDisplayMetrics().density;
return (int) (dpValue * scale + 0.5f);
}
/**
* @功能: 存储ImageSpan及其开始结束位置
* @author huangwei
* @2014年5月27日
* @下午5:21:37
*/
class IS
{
public ImageSpan is;
public int start;
public int end;
}
/**
* @功能: 存储测量好的一行数据
* @author huangwei
* @2014年5月27日
* @下午5:22:12
*/
class LINE
{
public ArrayList<Object> line = new ArrayList<Object>();
public ArrayList<Integer> widthList = new ArrayList<Integer>();
public int height;
@Override
public String toString()
{
StringBuilder sb = new StringBuilder("height:"+height+" ");
for(int i=0;i<line.size();i++)
{
sb.append(line.get(i)+":"+widthList.get(i));
}
return sb.toString();
}
}
/**
* @功能: 缓存的数据
* @author huangwei
* @2014年5月27日
* @下午5:22:25
*/
class MeasuredData
{
public int measuredHeight;
public float textSize;
public int width;
public float lineWidthMax;
ArrayList<LINE> contentList;
public int oneLineWidth;
public int hashIndex;
}
}
为方便在ListView中使用（ListView反复上下滑动会多次重新onMeasure）,加了缓存，相同的情况下可以不用重复在测量一次。
对于SpannableString，只支持了ImageSpan，有其它需要者可自行扩展
Demo：http://download.csdn.net/detail/yellowcath/7421147
或https://github.com/yellowcath/MTextView.git
Android 自绘TextView解决提前换行问题，支持图文混排,布布扣,bubuko.com
时间： 2024-10-25 17:59:03