51

我想在三行文本之后添加“更多”功能。文本包含超过 10 行的描述。所以我们决定在三行文字后面加上“更多”。喜欢：

在此处输入图像描述

当文本显示完整的描述时，它应该在文本末尾显示“Less”按钮，再次压缩TextView.

4

3 回答 3

104

试试这个可以帮助你和我一起工作。

    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.removeOnGlobalLayoutListener(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(SpannableString(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;
    }
}

更新：从 spaneble 文本中删除 UnderLine

  1. 创建自定义 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) {

    }
}
  1. addClickablePartTextViewResizable()方法的改变
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;
    }

输出：

在此处输入图像描述

在此处输入图像描述

于 2013-10-30T07:33:09.570 回答
28

这是一个简单的自定义ExpandableTextView。代替使用 See More 文本，它在底部使用 Compound Drawable：

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);
    }

}
于 2014-03-30T23:02:43.313 回答
8

如果字符串中有 \r\n 或 \n 这将换行

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;

}
于 2015-06-04T06:07:34.887 回答