如何获得可扩展的textview宽度以将其修剪长度设置为1行

Question

我正在使用可扩展文本视图显示文本的某些部分，并且当用户单击该文本视图时，用户可以看到该文本的整个字符串，我正在使用此示例，但是问题是可扩展文本视图的修剪长度固定，但是我想根据屏幕尺寸仅用一行设置动态调整长度，当我使用trim_length = 200时，显示的文本为3行，这是我的代码...

ExpandableTextView.java

public class ExpandableTextView extends TextView {
    private static final int DEFAULT_TRIM_LENGTH = 200;
    private static final String ELLIPSIS = ".....";

    private CharSequence originalText;
    private CharSequence trimmedText;
    private BufferType bufferType;
    private boolean trim = true;
    private int trimLength;

    public ExpandableTextView(Context context) {
        this(context, null);
    }

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

        TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.ExpandableTextView);
        this.trimLength = typedArray.getInt(R.styleable.ExpandableTextView_trimLength, DEFAULT_TRIM_LENGTH);
        typedArray.recycle();

        setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                trim = !trim;
                setText();
                requestFocusFromTouch();
            }
        });
    }

    private void setText() {
        super.setText(getDisplayableText(), bufferType);
    }

    private CharSequence getDisplayableText() {
        return trim ? trimmedText : originalText;
    }

    @Override
    public void setText(CharSequence text, BufferType type) {
        originalText = text;
        trimmedText = getTrimmedText(text);
        bufferType = type;
        setText();
    }

    private CharSequence getTrimmedText(CharSequence text) {
        if (originalText != null && originalText.length() > trimLength) {
            return new SpannableStringBuilder(originalText, 0, trimLength + 1).append(ELLIPSIS);
        } else {
            return originalText;
        }
    }

    public CharSequence getOriginalText() {
        return originalText;
    }

    public void setTrimLength(int trimLength) {
        this.trimLength = trimLength;
        trimmedText = getTrimmedText(originalText);
        setText();
    }

    public int getTrimLength() {
        return trimLength;
    }
}

ExpandableTextView expandableTextView =（ExpandableTextView）findViewById（R.id.lorem_ipsum）; expandableTextView.setText（yourText）;

Answer 1

你可以这样

public class ExpandableTextView extends TextView
{
    // copy off TextView.LINES
    private static final int MAXMODE_LINES = 1;
//    private OnExpandListener onExpandListener;
    private final int maxLines;
    private boolean expanded;


    public ExpandableTextView(final Context context)
    {
        this(context, null);
    }

    public ExpandableTextView(final Context context, final AttributeSet attrs)
    {
        this(context, attrs, 0);
    }

    public ExpandableTextView(final Context context, final AttributeSet attrs, final int defStyle)
    {
        super(context, attrs, defStyle);

        // read attributes
        final TypedArray attributes = context.obtainStyledAttributes(attrs, R.styleable.ExpandableTextView, defStyle, 0);
//        this.animationDuration = attributes.getInt(R.styleable.ExpandableTextView_trimLength, 200);
        attributes.recycle();

        // keep the original value of maxLines
        this.maxLines = this.getMaxLines();


    }

    @Override
    public int getMaxLines()
    {
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN)
        {
            return super.getMaxLines();
        }

        try
        {
            final Field mMaxMode = TextView.class.getField("mMaxMode");
            mMaxMode.setAccessible(true);
            final Field mMaximum = TextView.class.getField("mMaximum");
            mMaximum.setAccessible(true);

            final int mMaxModeValue = (int) mMaxMode.get(this);
            final int mMaximumValue = (int) mMaximum.get(this);

            return mMaxModeValue == MAXMODE_LINES ? mMaximumValue : -1;
        }
        catch (final Exception e)
        {
            return -1;
        }
    }

    public boolean toggle()
    {
        return this.expanded
                ? this.collapse()
                : this.expand();
    }


    public boolean expand()
    {
        if (!this.expanded && this.maxLines >= 0)
        {

            // set maxLines to MAX Integer, so we can calculate the expanded height
            this.setMaxLines(Integer.MAX_VALUE);


            // keep track of current status
            ExpandableTextView.this.expanded = true;


            return true;
        }

        return false;
    }


    public boolean collapse()
    {
        if (this.expanded && this.maxLines >= 0)
        {  

            ExpandableTextView.this.setMaxLines(ExpandableTextView.this.maxLines);
            // keep track of current status
            ExpandableTextView.this.expanded = false;


            return true;
        }

        return false;
    }
}

activity.xml

<com.yourpackagename.ExpandableTextView
            android:id="@+id/expandableTextView"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:ellipsize="end"
            android:maxLines="1"
     />

activity.java

ExpandableTextView expandableTextView = (ExpandableTextView) this.findViewById(R.id.expandableTextView);
expandableTextView.setOnClickListener(new View.OnClickListener()
        {
            @SuppressWarnings("ConstantConditions")
            @Override
            public void onClick(final View v)
            {
                expandableTextView.toggle();
            }
        });