Xamarin:无法从带有链接的 TextView 中检索 URLSpans [英] Xamarin: Unable to retrieve URLSpans from a TextView with links
问题描述
我正在尝试从 Xamarin 项目中的 textView 中删除链接下划线.以下代码段在 Java 项目中运行良好:
I'm trying to remove link underlines from textView in a Xamarin projects. The following snippet works well in a java project:
textView.setText("You must agree to our terms and conditions");
Pattern pattern1 = Pattern.compile("terms and conditions");
Linkify.addLinks(textView, pattern1, "http://www.someLink.com", null, new Linkify.TransformFilter() {
@Override
public String transformUrl(Matcher match, String url) {
return "";
}
});
Spannable s = new SpannableString(textView.getText());
URLSpan[] spans = s.getSpans(0, s.length(), URLSpan.class);
for (URLSpan span: spans) {
int start = s.getSpanStart(span);
int end = s.getSpanEnd(span);
NoUnderline noUnderline = new NoUnderline();
s.setSpan(noUnderline, start, end, 0);
}
textView.setText(s);
现在,在 C# 中翻译完全相同的代码,我得出以下结论:
Now, translating the exact same code in C#, I came to the following:
TextView.Text = "You must agree to our terms and conditions";
Java.Util.Regex.Pattern termsAndConditionsMatcher = Java.Util.Regex.Pattern.Compile("terms and conditions");
Linkify.AddLinks(TextView, termsAndConditionsMatcher, "https://www.someLink.com/", null, new EmptyLinkTransformer());
var spannable = new SpannableString(TextView.Text);
var spans = spannable.GetSpans(0, spannable.Length(), Java.Lang.Class.FromType(typeof(URLSpan)));
var urlSpans = new URLSpan[spans.Length];
for (var i = 0; i < urlSpans.Length; i++)
{
urlSpans[i] = spans[i] as URLSpan;
}
foreach (URLSpan span in urlSpans)
{
int start = spannable.GetSpanStart(span);
int end = spannable.GetSpanEnd(span);
var updated = new NoUnderlineSpan();
spannable.SetSpan(updated, start, end, 0);
}
TextView.TextFormatted = spannable;
问题是 spannable.GetSpans(0, spannable.Length(), Java.Lang.Class.FromType(typeof(URLSpan))) 返回 0 个元素,即使我看到了链接在 UI 上有颜色和下划线.
The problem is that spannable.GetSpans(0, spannable.Length(), Java.Lang.Class.FromType(typeof(URLSpan))) returns 0 elements, even though I see the links being colored and underlined on the UI.
This and this post suggest that I'm using the method correctly. Am I doing something wrong here?
推荐答案
Xamarin:无法从带有链接的 TextView 中检索 URLSpans
Xamarin: Unable to retrieve URLSpans from a TextView with links
这是一种解决方法:您可以使用 ClickableSpan
而不是 URLSpan
来实现相同的功能.
Here is a workaround: You could use ClickableSpan
instead of URLSpan
to implement the same feature.
自定义一个 ClickableSpan
类并覆盖 UpdateDrawState
以从超链接 TextView
中删除下划线:
Custom a ClickableSpan
class and override the UpdateDrawState
to remove underline from the hyperlink TextView
:
class MyClickableSpan : ClickableSpan
{
private MainActivity mainActivity;
public MyClickableSpan(MainActivity mainActivity)
{
this.mainActivity = mainActivity;
}
public override void OnClick(View widget)
{
Intent browserIntent = new Intent(Intent.ActionView, Uri.Parse("http://www.somelink.com/"));
mainActivity.StartActivity(browserIntent);
}
public override void UpdateDrawState(TextPaint ds)
{
base.UpdateDrawState(ds);
ds.Color = Color.Red;
ds.UnderlineText = false;
}
}
什么时候使用:
TextView textview = FindViewById<TextView>(Resource.Id.Terms);
//You need add this line
textview.MovementMethod = LinkMovementMethod.Instance;
//This is the Text of TextView
SpannableString ss1 = new SpannableString("You must agree to our terms and conditions");
//22 means start position, ss1.Length() means end position
ss1.SetSpan(new MyClickableSpan(this), 22, ss1.Length(), SpanTypes.ExclusiveExclusive);
//set text for your TextView
textview.TextFormatted = ss1;
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