自定义TextView显示指定行数

来源：互联网发布：mysql text 最大长度编辑：程序博客网时间：2024/06/05 15:47

接到需求，大段的商品介绍，默认情况先显示3行，其他没显示完的内容折叠，点击箭头后，展开显示全部文本。

这里写图片描述

其实很简单，只需要通过行高*行数，动态的设置TextView的高度。

直接贴代码：

/** * 多行textView显示指定行数 * Date: 2016-08-25 * * @author honjane */public class LineTextView extends LinearLayout {    private TextView mContentView;    private ImageView mArrowView;    private int mMaxLine;    private String mTextContent;    public LineTextView(Context context) {        this(context, null);    }    public LineTextView(Context context, AttributeSet attrs) {        this(context, attrs, 0);    }    @TargetApi(Build.VERSION_CODES.HONEYCOMB)    public LineTextView(Context context, AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);        initView();        initAttr(attrs);        bindListener();    }    private void initView() {        setOrientation(VERTICAL);        mContentView = new TextView(getContext());        addView(mContentView, new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT));        mArrowView = new ImageView(getContext());        mArrowView.setImageResource(R.drawable.arrow);        int padding = dip2px(getContext(), 5);        mArrowView.setPadding(padding, padding, padding, padding);        LinearLayout.LayoutParams params = new LinearLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);        params.gravity = Gravity.CENTER_HORIZONTAL;        addView(mArrowView, params);    }    private void initAttr(AttributeSet attrs) {        TypedArray typeArray = getContext().obtainStyledAttributes(attrs, R.styleable.LineTextStyle);        int textColor = typeArray.getColor(R.styleable.LineTextStyle_textColor, Color.BLACK);        int textSize = typeArray.getDimensionPixelSize(R.styleable.LineTextStyle_textSize, 12);        mMaxLine = typeArray.getInt(R.styleable.LineTextStyle_line, 2);        mTextContent = typeArray.getString(R.styleable.LineTextStyle_text);        bindTextView(textColor, textSize, mMaxLine, mTextContent);        typeArray.recycle();    }    private void bindTextView(int textColor, int textSize, final int maxLine, String textContent) {        mContentView.setText(textContent);        mContentView.setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize);        mContentView.setTextColor(textColor);        mContentView.setHeight(mContentView.getLineHeight() * maxLine);        //保证绘制完成才能回去到getLineCount值        post(new Runnable() {            @Override            public void run() {                mArrowView.setVisibility(mContentView.getLineCount() > maxLine ? VISIBLE : GONE);            }        });    }    private void bindListener() {        setOnClickListener(new OnClickListener() {            boolean isExpand;            @Override            public void onClick(View v) {                isExpand = !isExpand;                mContentView.clearAnimation();                final int deltaValue;                final int startValue = mContentView.getHeight();                int duration = 300;                //arrow 倒转动画                if (isExpand) {                    deltaValue = mContentView.getLineHeight() * mContentView.getLineCount() - startValue;                    RotateAnimation expandAnimation = new RotateAnimation(0, 180, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);                    expandAnimation.setDuration(duration);                    expandAnimation.setFillAfter(true);                    mArrowView.startAnimation(expandAnimation);                } else {                    deltaValue = mContentView.getLineHeight() * mMaxLine - startValue;                    RotateAnimation foldAnimation = new RotateAnimation(180, 0, Animation.RELATIVE_TO_SELF, 0.5f, Animation.RELATIVE_TO_SELF, 0.5f);                    foldAnimation.setDuration(duration);                    foldAnimation.setFillAfter(true);                    mArrowView.startAnimation(foldAnimation);                }                //text 展开动画                Animation textAnim = new Animation() {                    @Override                    protected void applyTransformation(float interpolatedTime, Transformation trans) {                        super.applyTransformation(interpolatedTime, trans);                        mContentView.setHeight((int) (startValue + deltaValue * interpolatedTime));                    }                };                textAnim.setDuration(duration);                mContentView.startAnimation(textAnim);            }        });    }    public String getText() {        return mTextContent;    }    public void setText(CharSequence charSequence) {        mContentView.setText(charSequence);    }    public static int dip2px(Context context, float dipValue) {        final float scale = context.getResources().getDisplayMetrics().density;        return (int) (dipValue * scale + 0.5f);    }}

attr.xml文件

<?xml version="1.0" encoding="utf-8"?><resources>    <declare-styleable name="LineTextStyle">        <attr name="textSize" format="dimension"/>        <attr name="textColor" format="color"/>        <attr name="line" format="integer" />        <attr name="text" format="string" />    </declare-styleable></resources>

使用还是与TextView用法相似，没什么改动，使用的时候注意命名空间

<com.honjane.linetext.LineTextView        xmlns:more="http://schemas.android.com/apk/res-auto"        android:layout_width="match_parent"        android:layout_height="wrap_content"        android:layout_margin="5dip"         more:textColor="@android:color/black"        more:textSize="14dip"        more:line="3"        more:text="@string/text"/>

0 0