Linkify() -激活链接

Question

我已经在弹出对话框中添加了指向由方括号包围的文本的链接。然而，这些链接是不可点击的(当它们被按下时没有任何反应)。我想不出为什么(！)

下面是我的对话框活动：

public void popupDefinition(CharSequence term, LinkedHashMap<String, String> dictionaryMap){
    SpannableString definition = new SpannableString(dictionaryMap.get(term)); // grab the definition by checking against the dictionary map hash
    Linkify.addLinks(definition, pattern, scheme); // find text in square brackets, add links

    AlertDialog alertDialog = new AlertDialog.Builder(ListProjectActivity.this).create(); // create a dialog box
    alertDialog.setMessage(definitionFormatted); // set dialog box message
    alertDialog.show(); // actually display the dialog box
    }

‘'scheme’和'pattern‘在前面已经定义好了，如下所示：

final static Pattern pattern = Pattern.compile("\\[[^]]*]"); // defines the fact that links are bound by [square brackets]
final String scheme = "http://example.com/"; // THIS IS NOT WORKING

为什么，当我点击出现的链接(它们以蓝色下划线显示)时，它们没有引起任何响应？

我实际上并没有尝试启动URL链接(当它发生时，我将重定向ACTION_VIEW意图)，但我需要在开始之前确认是否发生了某种响应……

Answer 1

我实际上并不是在尝试启动

链接

由于您不需要使用URLSpans，因此不需要尝试创建自定义链接方案，因为它只创建URL。您只需要从TextView中的关键字启动一个活动。正如我在你的一个类似的，但不是复制的问题中所说的，我会使用一个自定义的跨度，介绍ActivitySpan：

public class ActivitySpan extends ClickableSpan {
    String keyword;
    public ActivitySpan(String keyword) {
        super();
        this.keyword = keyword;
    }

    @Override
    public void onClick(View v) {
        Context context = v.getContext();
        Intent intent = new Intent(context, AnotherActivity.class);
        intent.putExtra("keyword", keyword);
        context.startActivity(intent);
    }
}

这里没有铃声或口哨，这个跨度接受一个你用括号括起来的[keyword]，并将它传递给另一个活动。

虽然我不喜欢因为URLSpans而使用Linkify的想法，但它的模式匹配和跨度创建非常棒，所以我复制并修改了它：

private void addLinks(TextView textView, Pattern pattern) {
    SpannableString spannable = SpannableString.valueOf(textView.getText());
    Matcher matcher = pattern.matcher(spannable);

    // Create ActivitySpans for each match
    while (matcher.find())
        spannable.setSpan(new ActivitySpan(matcher.group()), matcher.start(), matcher.end(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

    // Set new spans in TextView
    textView.setText(spannable);

    // Listen for spannable clicks, if not already
    MovementMethod m = textView.getMovementMethod();
    if ((m == null) || !(m instanceof LinkMovementMethod)) {
        if (textView.getLinksClickable()) {
            textView.setMovementMethod(LinkMovementMethod.getInstance());
        }
    }
}

注意，此方法不会删除每个关键字周围的[brackets]，但您可以在while循环中轻松完成此操作。

要使用它，只需在onCreate()和Voila中将TextView和模式传递给addLinks()！

下面是一个实用的示例：

public class Example extends Activity {
    Pattern pattern = Pattern.compile("\\[[^]]*]");

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        popupDefinition("Example: A [pattern] or [model], as of something to be [imitated] or [avoided]");
    }

    // It seems like you can call "popupDefinition(dictionaryMap.get(term));" rather than pass both.  
    public void popupDefinition(String string){
        SpannableString spannable = new SpannableString(string);
        Matcher matcher = pattern.matcher(spannable);

        // Create ActivitySpans for each match
        while (matcher.find())
            spannable.setSpan(new ActivitySpan(matcher.group()), matcher.start(), matcher.end(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);

        // Create a new TextView with these spans and enable the clickable links
        TextView textView = new TextView(this);
        textView.setText(spannable);
        textView.setMovementMethod(LinkMovementMethod.getInstance());

        // Create and display an AlertDialog with this TextView
        AlertDialog alertDialog = new AlertDialog.Builder(this)
                .setView(textView)
                .create(); 
        alertDialog.show(); 
    }


    public class ActivitySpan extends ClickableSpan {
        String keyword;
        public ActivitySpan(String keyword) {
            super();
            this.keyword = keyword;
        }

        @Override
        public void onClick(View v) {
            Context context = v.getContext();
            Toast.makeText(context, keyword, Toast.LENGTH_SHORT).show();
        }
    }
}