问题
I have a multi-line TextView that has android:ellipsize=\"end\" set. I would like to know, however, if the string I place in there is actually too long (so that I may make sure the full string is shown elsewhere on the page).
I could use TextView.length() and find about what the approximate length of string will fit, but since it\'s multiple lines, the TextView handles when to wrap, so this won\'t always work.
Any ideas?
回答1:
You can get the layout of the TextView and check the ellipsis count per line. For an end ellipsis, it is sufficient to check the last line, like this:
Layout l = textview.getLayout();
if (l != null) {
int lines = l.getLineCount();
if (lines > 0)
if (l.getEllipsisCount(lines-1) > 0)
Log.d(TAG, "Text is ellipsized");
}
This only works after the layout phase, otherwise the returned layout will be null, so call this at an appropriate place in your code.
回答2:
textView.getLayout is the way to go but the problem with that is that it returns null if layout is not prepared. Use the below solution.
ViewTreeObserver vto = textview.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
Layout l = textview.getLayout();
if ( l != null){
int lines = l.getLineCount();
if ( lines > 0)
if ( l.getEllipsisCount(lines-1) > 0)
Log.d(TAG, "Text is ellipsized");
}
}
});
回答3:
I think the easiest solution to this question is the following code:
String text = "some looooong text";
textView.setText(text);
boolean isEllipsize = !((textView.getLayout().getText().toString()).equalsIgnoreCase(text));
This code assumes that in your XML the TextView set a maxLineCount :)
回答4:
This worked to me:
textView.post(new Runnable() {
@Override
public void run() {
if (textView.getLineCount() > 1) {
//do something
}
}
});
回答5:
public int getEllipsisCount (int line):
Returns the number of characters to be ellipsized away, or 0 if no ellipsis is to take place.
So, simply call :
int lineCount = textview1.getLineCount();
if(textview1.getLayout().getEllipsisCount(lineCount) > 0) {
// Do anything here..
}
Since the getLayout() cant be called before the layout is set, use this:
ViewTreeObserver vto = textview.getViewTreeObserver();
vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {
@Override
public void onGlobalLayout() {
Layout l = textview.getLayout();
if ( l != null){
int lines = l.getLineCount();
if ( lines > 0)
if ( l.getEllipsisCount(lines-1) > 0)
Log.d(TAG, "Text is ellipsized");
}
}
});
And finally do not forget to remove removeOnGlobalLayoutListener when you need it nomore.
回答6:
lateinit var toggleMoreButton: Runnable
toggleMoreButton = Runnable {
if(reviewTextView.layout == null) { // wait while layout become available
reviewTextView.post(toggleMoreButton)
return@Runnable
}
readMoreButton.visibility = if(reviewTextView.layout.text.toString() != comment) View.VISIBLE else View.GONE
}
reviewTextView.post(toggleMoreButton)
It is some typical case:
- comment in 'reviewTextView'
- comment can collapsed by some criteria
- if comment collapsed you show button 'readMoreButton'
回答7:
it is working for me
if (l != null) {
int lines = l.getLineCount();
if (lines > 0) {
for (int i = 0; i < lines; i++) {
if (l.getEllipsisCount(i) > 0) {
ellipsize = true;
break;
}
}
}
}
回答8:
Really work so, for example, to pass full data to dialog from item of RecyclerView:
holder.subInfo.post(new Runnable() {
@Override
public void run() {
Layout l = holder.subInfo.getLayout();
if (l != null) {
final int count = l.getLineCount();
if (count >= 3) {
holder.subInfo.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
final int c = holder.subInfo.getLineCount();
if (c >= 3) {
onClickToShowInfoDialog.showDialog(holder.title.getText().toString(), holder.subInfo.getText().toString());
}
}
});
}
}
}
});
回答9:
The Kotlin way:
textView.post {
if (textView.lineCount > MAX_LINES_COLLAPSED) {
// text is not fully displayed
}
}
Actually View.post() is executed after the view has been rendered and will run the function provided
回答10:
Combining @Thorstenvv awnser with @Tiano fix, here is the Kotlin version :
val layout = textView.layout ?: return@doOnLayout
val lines = layout.lineCount
val hasLine = lines > 0
val hasEllipsis = ((lines - 1) downTo 0).any { layout.getEllipsisCount(it) > 0 }
if (hasLine && hasEllipsis) {
// Text is ellipsized
}
回答11:
Using getEllipsisCount won't work with text that has empty lines within it. I used the following code to make it work :
message.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
@Override
public boolean onPreDraw() {
if(m.isEllipsized == -1) {
Layout l = message.getLayout();
if (message.getLineCount() > 5) {
m.isEllipsized = 1;
message.setMaxLines(5);
return false;
} else {
m.isEllipsized = 0;
}
}
return true;
}
});
Make sure not to set a maxLineCount in your XML. Then you can check for the lineCount in your code and if it is greater than a certain number, you can return false to cancel the drawing of the TextView and set the line count as well as a flag to save whether the text view is too long or not. The text view will draw again with the correct line count and you will know whether its ellipsized or not with the flag.
You can then use the isEllipsized flag to do whatever you require.
回答12:
create a method inside your TextViewUtils class
public static boolean isEllipsized(String newValue, String oldValue) {
return !((newValue).equals(oldValue));
}
call this method when it's required eg:
if (TextViewUtils.isEllipsized(textviewDescription.getLayout().getText().toString(), yourModelObject.getDescription()))
holder.viewMore.setVisibility(View.VISIBLE);//show view more option
else
holder.viewMore.setVisibility(View.GONE);//hide
but textView.getLayout() can't call before the view(layout) set.
来源：https://stackoverflow.com/questions/4005933/how-do-i-tell-if-my-textview-has-been-ellipsized