Add “View More” at the end of textview after 3 lin

2019-01-04 19:29发布

This question already has an answer here:

I want to add "More" functionality after three lines of text. The text contains the description which is more than 10 lines. so we have decided to add "More" after three lines of text. Like:

enter image description here

when the text is showing the complete description, then it should show "Less" button at the end of text which again compress the textview.

3条回答
Root(大扎)
2楼-- · 2019-01-04 20:04

Here is a simple custom ExpandableTextView. Instead using See More text, it uses Compound Drawable on the Bottom:

public class ExpandableTextView extends TextView implements OnClickListener
{   
    private static final int MAX_LINES = 5;
    private int currentMaxLines = Integer.MAX_VALUE;

    public ExpandableTextView(Context context)
    {
        super(context);
        setOnClickListener(this);
    }
    public ExpandableTextView(Context context, AttributeSet attrs, int defStyle)
    {
        super(context, attrs, defStyle);
        setOnClickListener(this);
    }

    public ExpandableTextView(Context context, AttributeSet attrs)
    {
        super(context, attrs);
        setOnClickListener(this);
    }

    @Override
    protected void onTextChanged(CharSequence text, int start, int lengthBefore, int lengthAfter)
    {
        /* If text longer than MAX_LINES set DrawableBottom - I'm using '...' icon */
        post(new Runnable()
        {
            public void run()
            {
                if (getLineCount()>MAX_LINES)
                    setCompoundDrawablesWithIntrinsicBounds(0, 0, 0, R.drawable.icon_more_text);
                else
                    setCompoundDrawablesWithIntrinsicBounds(0, 0, 0, 0);

                setMaxLines(MAX_LINES);             
            }
        });
    }


    @Override
    public void setMaxLines(int maxLines)
    {
        currentMaxLines = maxLines;
        super.setMaxLines(maxLines);
    }

    /* Custom method because standard getMaxLines() requires API > 16 */
    public int getMyMaxLines()
    {
        return currentMaxLines;
    }

    @Override
    public void onClick(View v)
    {
        /* Toggle between expanded collapsed states */
        if (getMyMaxLines() == Integer.MAX_VALUE)
            setMaxLines(MAX_LINES);
        else
            setMaxLines(Integer.MAX_VALUE);
    }

}
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三岁会撩人
3楼-- · 2019-01-04 20:09

This Will break Line if there is \r\n or \n in string

public static void makeTextViewResizable(final TextView tv,
        final int maxLine, final String expandText, final boolean viewMore) {

    if (tv.getTag() == null) {
        tv.setTag(tv.getText());
    }
    ViewTreeObserver vto = tv.getViewTreeObserver();
    vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

        @SuppressWarnings("deprecation")
        @Override
        public void onGlobalLayout() {

            ViewTreeObserver obs = tv.getViewTreeObserver();
            obs.removeGlobalOnLayoutListener(this);
            if (maxLine == 0) {
                int lineEndIndex = tv.getLayout().getLineEnd(0);
                String text = tv.getText().subSequence(0,
                        lineEndIndex - expandText.length() + 1)
                        + " " + expandText;
                tv.setText(text);
                tv.setMovementMethod(LinkMovementMethod.getInstance());
                tv.setText(
                        addClickablePartTextViewResizable(tv.getText()
                                .toString(), tv, maxLine, expandText,
                                viewMore), BufferType.SPANNABLE);
            } else if (maxLine > 0 && tv.getLineCount() >= maxLine) {
                int lineEndIndex = tv.getLayout().getLineEnd(maxLine - 1);
                String text = tv.getText().subSequence(0,
                        lineEndIndex - expandText.length() + 1)
                        + " " + expandText;
                tv.setText(text);
                tv.setMovementMethod(LinkMovementMethod.getInstance());
                tv.setText(
                        addClickablePartTextViewResizable(tv.getText()
                                .toString(), tv, maxLine, expandText,
                                viewMore), BufferType.SPANNABLE);
            } else {
                int lineEndIndex = tv.getLayout().getLineEnd(
                        tv.getLayout().getLineCount() - 1);
                String text = tv.getText().subSequence(0, lineEndIndex)
                        + " " + expandText;
                tv.setText(text);
                tv.setMovementMethod(LinkMovementMethod.getInstance());
                tv.setText(
                        addClickablePartTextViewResizable(tv.getText()
                                .toString(), tv, lineEndIndex, expandText,
                                viewMore), BufferType.SPANNABLE);
            }
        }
    });

}

private static SpannableStringBuilder addClickablePartTextViewResizable(
        final String strSpanned, final TextView tv, final int maxLine,
        final String spanableText, final boolean viewMore) {
    SpannableStringBuilder ssb = new SpannableStringBuilder(strSpanned);

    if (strSpanned.contains(spanableText)) {
        ssb.setSpan(
                new ClickableSpan() {

                    @Override
                    public void onClick(View widget) {

                        if (viewMore) {
                            tv.setLayoutParams(tv.getLayoutParams());
                            tv.setText(tv.getTag().toString(),
                                    BufferType.SPANNABLE);
                            tv.invalidate();
                            makeTextViewResizable(tv, -5, "...Read Less",
                                    false);
                            tv.setTextColor(Color.BLACK);
                        } else {
                            tv.setLayoutParams(tv.getLayoutParams());
                            tv.setText(tv.getTag().toString(),
                                    BufferType.SPANNABLE);
                            tv.invalidate();
                            makeTextViewResizable(tv, 5, "...Read More",
                                    true);
                            tv.setTextColor(Color.BLACK);
                        }

                    }
                }, strSpanned.indexOf(spanableText),
                strSpanned.indexOf(spanableText) + spanableText.length(), 0);

    }
    return ssb;

}
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Luminary・发光体
4楼-- · 2019-01-04 20:19

Try this may helps you working fine with me.

    public class MainActivity extends Activity {

    TextView tv;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        tv = (TextView) findViewById(R.id.tv);
        makeTextViewResizable(tv, 3, "View More", true);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);

        return true;
    }

    public static void makeTextViewResizable(final TextView tv, final int maxLine, final String expandText, final boolean viewMore) {

        if (tv.getTag() == null) {
            tv.setTag(tv.getText());
        }
        ViewTreeObserver vto = tv.getViewTreeObserver();
        vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

            @SuppressWarnings("deprecation")
            @Override
            public void onGlobalLayout() {
                String text;
                int lineEndIndex;
                ViewTreeObserver obs = tv.getViewTreeObserver();
                obs.removeGlobalOnLayoutListener(this);
                if (maxLine == 0) {
                    lineEndIndex = tv.getLayout().getLineEnd(0);
                    text = tv.getText().subSequence(0, lineEndIndex - expandText.length() + 1) + " " + expandText;
                } else if (maxLine > 0 && tv.getLineCount() >= maxLine) {
                    lineEndIndex = tv.getLayout().getLineEnd(maxLine - 1);
                    text = tv.getText().subSequence(0, lineEndIndex - expandText.length() + 1) + " " + expandText;
                } else {
                    lineEndIndex = tv.getLayout().getLineEnd(tv.getLayout().getLineCount() - 1);
                    text = tv.getText().subSequence(0, lineEndIndex) + " " + expandText;
                }
                tv.setText(text);
                tv.setMovementMethod(LinkMovementMethod.getInstance());
                tv.setText(
                            addClickablePartTextViewResizable(Html.fromHtml(tv.getText().toString()), tv, lineEndIndex, expandText,
                                    viewMore), BufferType.SPANNABLE);
            }
        });

    }

    private static SpannableStringBuilder addClickablePartTextViewResizable(final Spanned strSpanned, final TextView tv,
            final int maxLine, final String spanableText, final boolean viewMore) {
        String str = strSpanned.toString();
        SpannableStringBuilder ssb = new SpannableStringBuilder(strSpanned);

        if (str.contains(spanableText)) {
            ssb.setSpan(new ClickableSpan() {

                @Override
                public void onClick(View widget) {
                        tv.setLayoutParams(tv.getLayoutParams());
                        tv.setText(tv.getTag().toString(), BufferType.SPANNABLE);
                        tv.invalidate();
                    if (viewMore) {
                        makeTextViewResizable(tv, -1, "View Less", false);
                    } else {
                        makeTextViewResizable(tv, 3, "View More", true);
                    }

                }
            }, str.indexOf(spanableText), str.indexOf(spanableText) + spanableText.length(), 0);

        }
        return ssb;

    }

}

UPDATE : Remove UnderLine from spaneble text

1) Create Custom ClickableSpan

public class MySpannable extends ClickableSpan {

    private boolean isUnderline = false;

    /**
     * Constructor
     */
    public MySpannable(boolean isUnderline) {
        this.isUnderline = isUnderline;
    }

    @Override
    public void updateDrawState(TextPaint ds) {

        ds.setUnderlineText(isUnderline);
        ds.setColor(Color.parseColor("#343434"));

    }

    @Override
    public void onClick(View widget) {

    }
}

2) Change in addClickablePartTextViewResizable() method

private static SpannableStringBuilder addClickablePartTextViewResizable(final Spanned strSpanned, final TextView tv,
                                                                            final int maxLine, final String spanableText, final boolean viewMore) {
        String str = strSpanned.toString();
        SpannableStringBuilder ssb = new SpannableStringBuilder(strSpanned);

        if (str.contains(spanableText)) {


            ssb.setSpan(new MySpannable(false){
                @Override
                public void onClick(View widget) {
                        tv.setLayoutParams(tv.getLayoutParams());
                        tv.setText(tv.getTag().toString(), BufferType.SPANNABLE);
                        tv.invalidate();
                    if (viewMore) {
                        makeTextViewResizable(tv, -1, "View Less", false);
                    } else {
                        makeTextViewResizable(tv, 3, "View More", true);
                    }
                }
            }, str.indexOf(spanableText), str.indexOf(spanableText) + spanableText.length(), 0);

        }
        return ssb;

    }

OutPut:

enter image description here

enter image description here

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