android去掉超文本、超链接的下划线——终极解决方案
程序员文章站
2022-06-01 09:11:28
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在开发中，有时需要对文本之中的超链接或者类似于微博#话题#这样特殊文本进行过滤，包括特殊字符的点击事件，以及颜色处理，比如这样
超文本.jpg
这样的需求可以用原生的Linkify类来处理，下面是一个用来过滤http://或者https的链接写法，通过我们自己写的正则表达式来过滤超文本，然后原生的Linkify会给符合我们定义的规则（例如微博#话题#）改变颜色，并且点击可以特殊处理，与正常点击recyclerview或者lsitview条目跳转不同
/**
* 设置textview里面链接点击后跳转
*
* @param itemView 点击文字时，若点击区域不是链接，
默认是哪个view响应点击事件，通常情况就是listView或recyclerView的itemView
*/
public static void setURLClickEvent(final TextView tv, final View itemView) {
String text = tv.getText().toString();
if (!text.contains("http://") && !text.contains("https://") && !text.contains("ftp://") && !text.contains("$") && !text.contains("#")) {
tv.setMovementMethod(null);
return;
}
tv.setMovementMethod(LinkMovementMethod.getInstance());
tv.setAutoLinkMask(0);
tv.setLinksClickable(true);
String scheme2 = String.format("%s/?%s=", "lcsdevdiv://sina_lcs_profile_", "uid");
tv.setLinkTextColor(FrameworkApp.getInstance().getResources().getColor(R.color.color_lcs_blue_pressed));
Pattern pattern2 =
Pattern.compile("((http[s]{0,1}|ftp)://[a-zA-Z0-9\\.\\-]+\\.([a-zA-Z]{2,4})(:\\d+)?(/[a-zA-Z0-9\\.\\aaa@qq.com#$%^&*+?:_/=<>]*)?)|(www.[a-zA-Z0-9\\.\\-]+\\.([a-zA-Z]{2,4})(:\\d+)?(/[a-zA-Z0-9\\.\\aaa@qq.com#$%^&*+?:_/=<>]*)?)");
addLinks(tv, pattern2, scheme2, null, new Linkify.TransformFilter() {
@Override
public String transformUrl(Matcher match, String url) {
return URLEncoder.encode(url);
}
});
}
但是如何改变超文本的颜色呢？Textview已经提供了原生的方法
image.png
tv.setLinkTextColor(FrameworkApp.getInstance().getResources().getColor(R.color.color_lcs_blue_pressed));
但是如果挑剔的设计师想要去掉原生的下划线，怎么办，原生的Textview并没有提供修改下划线的方法
我们先去看看源码，在Linkify这个类中475行
image.png
private static final void applyLink(String url, int start, int end, Spannable text) {
URLSpan span = new URLSpan(url);
text.setSpan(span, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
}
看到这个私有的添加链接的方法，然后找到找到URLSpan ，发现
image.png
URLSpan 继承 ClickableSpan这个类
image.png
/**
* Makes the text underlined and in the link color.
*/
@Override
public void updateDrawState(TextPaint ds) {
ds.setColor(ds.linkColor);
ds.setUnderlineText(true);
}
这里updateDrawState方法是设置下划线的核心操作，我们可以自己写一个类继承URLSpan 设置不显示下划线
image.png
image.png
在设置完超链接过滤之后，重新设置一个Spannable 确实可以去掉下划线，也许你会以为，我去这也太简单了吧，但其实这里面的坑还有很多，
如果一个列表的item里不止一处需要过滤超文本，这样的做法就会有问题
image.png
重写updateDrawState方法虽然可以去掉下划线，但是会严重影响我们之前定义超文本的校验，也就是说之前过滤的文本内容会被重新设置一次，这是为什么呢，我们看一下源码和我们设置Spannable的区别
源码：
image.png
自定义的
image.png
这里的length长度是有问题的，他是全部文本的长度，但是我们怎么能拿到每次过滤之后超文本/超链接开始和结束的长度呢？
最简单的办法就是把源码拿过来，只改变URLSpan 里面的ds.setUnderlineText(false);设置为false
我们先把触发设置下划线的方法拿过来，addLinks 重载方法，相关的方法全部拿过来
public static final void addLinks(@NonNull TextView text, @NonNull Pattern pattern,
@Nullable String scheme, @Nullable Linkify.MatchFilter matchFilter,
@Nullable Linkify.TransformFilter transformFilter) {
addLinks(text, pattern, scheme, null, matchFilter, transformFilter);
}
public static void addLinks(@NonNull TextView text, @NonNull Pattern pattern,
@Nullable String defaultScheme, @Nullable String[] schemes,
@Nullable Linkify.MatchFilter matchFilter, @Nullable Linkify.TransformFilter transformFilter) {
SpannableString spannable = SpannableString.valueOf(text.getText());
boolean linksAdded = addLinks(spannable, pattern, defaultScheme, schemes, matchFilter,
transformFilter);
if (linksAdded) {
text.setText(spannable);
addLinkMovementMethod(text);
}
}
public static final boolean addLinks(@NonNull Spannable spannable, @NonNull Pattern pattern,
@Nullable String defaultScheme, @Nullable String[] schemes,
@Nullable Linkify.MatchFilter matchFilter, @Nullable Linkify.TransformFilter transformFilter) {
final String[] schemesCopy;
if (defaultScheme == null) defaultScheme = "";
if (schemes == null || schemes.length < 1) {
schemes = new String[]{};
}
schemesCopy = new String[schemes.length + 1];
schemesCopy[0] = defaultScheme.toLowerCase(Locale.ROOT);
for (int index = 0; index < schemes.length; index++) {
String scheme = schemes[index];
schemesCopy[index + 1] = (scheme == null) ? "" : scheme.toLowerCase(Locale.ROOT);
}
boolean hasMatches = false;
Matcher m = pattern.matcher(spannable);
while (m.find()) {
int start = m.start();
int end = m.end();
boolean allowed = true;
if (matchFilter != null) {
allowed = matchFilter.acceptMatch(spannable, start, end);
}
if (allowed) {
String url = makeUrl(m.group(0), schemesCopy, m, transformFilter);
NoLineClickableSpan span = new NoLineClickableSpan(url);
spannable.setSpan(span, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
hasMatches = true;
}
}
return hasMatches;
}
private static final String makeUrl(@NonNull String url, @NonNull String[] prefixes,
Matcher matcher, @Nullable Linkify.TransformFilter filter) {
if (filter != null) {
url = filter.transformUrl(matcher, url);
}
boolean hasPrefix = false;
for (int i = 0; i < prefixes.length; i++) {
if (url.regionMatches(true, 0, prefixes[i], 0, prefixes[i].length())) {
hasPrefix = true;
// Fix capitalization if necessary
if (!url.regionMatches(false, 0, prefixes[i], 0, prefixes[i].length())) {
url = prefixes[i] + url.substring(prefixes[i].length());
}
break;
}
}
if (!hasPrefix && prefixes.length > 0) {
url = prefixes[0] + url;
}
return url;
}
private static final void addLinkMovementMethod(@NonNull TextView t) {
MovementMethod m = t.getMovementMethod();
if ((m == null) || !(m instanceof LinkMovementMethod)) {
if (t.getLinksClickable()) {
t.setMovementMethod(LinkMovementMethod.getInstance());
}
}
}
image.png
注意这里换成我们自定义的Span,然后重新设置的spanable就会保留之前的正则过滤并且干掉下划线
下面贴上完整工具类，亲测可用：
public class CircleUtils {
/**
* 设置textview里面链接点击后跳转
*
* @param itemView 点击文字时，若点击区域不是链接， 默认是哪个view响应点击事件，通常情况就是listView或recyclerView的itemView
*/
public static void setURLClickEvent(final TextView tv, final View itemView) {
String text = tv.getText().toString();
if (!text.contains("http://") && !text.contains("https://") && !text.contains("ftp://") && !text.contains("$") && !text.contains("#")) {
tv.setMovementMethod(null);
return;
}
tv.setMovementMethod(LinkMovementMethod.getInstance());
tv.setAutoLinkMask(0);
tv.setLinksClickable(true);
final String targetId = getTagData(tv);
Pattern pattern0 = Pattern.compile("\\#.*?\\#");
String scheme0 = String.format("%s/?%s=", "lcsdevdiv://sina_lcs_profile_", "targetid");
addLinks(tv, pattern0, scheme0, new Linkify.MatchFilter() {
@Override
public boolean acceptMatch(CharSequence s, int start, int end) {
if(!TextUtils.isEmpty(targetId)) {
//如果有观点链接，肯定是拼在最前面
if(start == 0) {
return true;
}
}
return false;
}
}, new Linkify.TransformFilter() {
@Override
public String transformUrl(Matcher match, String url) {
return targetId;
}
});
Pattern pattern = Pattern.compile("\\$[^$]+?(sh|sz|gn|hy|dy)[A-Z]?[A-Z]?[0-9]{6}\\)?\\$");
String scheme1 = String.format("%s/?%s=", "lcsdevdiv://sina_lcs_profile_", "keyword");
addLinks(tv, pattern, scheme1, null, new Linkify.TransformFilter() {
@Override
public String transformUrl(Matcher match, String url) {
String keyword = url.substring(1, match.group(0).length());
Matcher m = Pattern.compile("\\(.*\\)").matcher(keyword);
if (m.find()) {
keyword = m.group(0);
keyword = keyword.replaceAll("\\(", "");
keyword = keyword.replaceAll("\\)", "");
}
return keyword;
}
});
String scheme2 = String.format("%s/?%s=", "lcsdevdiv://sina_lcs_profile_", "uid");
tv.setLinkTextColor(FrameworkApp.getInstance().getResources().getColor(R.color.color_lcs_blue_pressed));
Pattern pattern2 = Pattern.compile("((http[s]{0,1}|ftp)://[a-zA-Z0-9\\.\\-]+\\.([a-zA-Z]{2,4})(:\\d+)?(/[a-zA-Z0-9\\.\\aaa@qq.com#$%^&*+?:_/=<>]*)?)|(www.[a-zA-Z0-9\\.\\-]+\\.([a-zA-Z]{2,4})(:\\d+)?(/[a-zA-Z0-9\\.\\aaa@qq.com#$%^&*+?:_/=<>]*)?)");
addLinks(tv, pattern2, scheme2, null, new Linkify.TransformFilter() {
@Override
public String transformUrl(Matcher match, String url) {
return URLEncoder.encode(url);
}
});
}
private static String getTagData(TextView view) {
String result = "";
try {
Object object = view.getTag();
if(object != null) {
result = object.toString();
}
} catch (Exception e) {
e.printStackTrace();
}
return result;
}
public static final void addLinks(@NonNull TextView text, @NonNull Pattern pattern,
@Nullable String scheme, @Nullable Linkify.MatchFilter matchFilter,
@Nullable Linkify.TransformFilter transformFilter) {
addLinks(text, pattern, scheme, null, matchFilter, transformFilter);
}
public static void addLinks(@NonNull TextView text, @NonNull Pattern pattern,
@Nullable String defaultScheme, @Nullable String[] schemes,
@Nullable Linkify.MatchFilter matchFilter, @Nullable Linkify.TransformFilter transformFilter) {
SpannableString spannable = SpannableString.valueOf(text.getText());
boolean linksAdded = addLinks(spannable, pattern, defaultScheme, schemes, matchFilter,
transformFilter);
if (linksAdded) {
text.setText(spannable);
addLinkMovementMethod(text);
}
}
public static final boolean addLinks(@NonNull Spannable spannable, @NonNull Pattern pattern,
@Nullable String defaultScheme, @Nullable String[] schemes,
@Nullable Linkify.MatchFilter matchFilter, @Nullable Linkify.TransformFilter transformFilter) {
final String[] schemesCopy;
if (defaultScheme == null) defaultScheme = "";
if (schemes == null || schemes.length < 1) {
schemes = new String[]{};
}
schemesCopy = new String[schemes.length + 1];
schemesCopy[0] = defaultScheme.toLowerCase(Locale.ROOT);
for (int index = 0; index < schemes.length; index++) {
String scheme = schemes[index];
schemesCopy[index + 1] = (scheme == null) ? "" : scheme.toLowerCase(Locale.ROOT);
}
boolean hasMatches = false;
Matcher m = pattern.matcher(spannable);
while (m.find()) {
int start = m.start();
int end = m.end();
boolean allowed = true;
if (matchFilter != null) {
allowed = matchFilter.acceptMatch(spannable, start, end);
}
if (allowed) {
String url = makeUrl(m.group(0), schemesCopy, m, transformFilter);
NoLineClickableSpan span = new NoLineClickableSpan(url);
spannable.setSpan(span, start, end, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
hasMatches = true;
}
}
return hasMatches;
}
private static final String makeUrl(@NonNull String url, @NonNull String[] prefixes,
Matcher matcher, @Nullable Linkify.TransformFilter filter) {
if (filter != null) {
url = filter.transformUrl(matcher, url);
}
boolean hasPrefix = false;
for (int i = 0; i < prefixes.length; i++) {
if (url.regionMatches(true, 0, prefixes[i], 0, prefixes[i].length())) {
hasPrefix = true;
// Fix capitalization if necessary
if (!url.regionMatches(false, 0, prefixes[i], 0, prefixes[i].length())) {
url = prefixes[i] + url.substring(prefixes[i].length());
}
break;
}
}
if (!hasPrefix && prefixes.length > 0) {
url = prefixes[0] + url;
}
return url;
}
private static final void addLinkMovementMethod(@NonNull TextView t) {
MovementMethod m = t.getMovementMethod();
if ((m == null) || !(m instanceof LinkMovementMethod)) {
if (t.getLinksClickable()) {
t.setMovementMethod(LinkMovementMethod.getInstance());
}
}
}
}