带圆角的背景的TextView

效果图

应用中经常会遇到使用圆角TextView的情况，这是一个自定义的圆角TextView

类文件

/**

 * 带圆角的文本显示控件textview
 * Created by Bear on 2017/6/23.
 */
class RoundTextView @JvmOverloads constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int = 0) :
        AppCompatTextView(context, attrs, defStyleAttr) {
    private var mPaint: Paint = Paint()
    private var mBgColor: Int = 0 //背景颜色
    private var mRoundSize: Float = 0.toFloat() //圆角的值
    private var mRoundType = RoundType.ROUND_RECT //圆角的类型
    private var rectF: RectF? = null


    enum class RoundType {
        ROUND_RECT,

        ROUND_TOP,

        ROUND_BOTTOM,

        LEFT_BOTTOM,

        RIGHT_BOTTOM
    }

    init {
        if (attrs != null)
            init(attrs)
    }

    /**
     * 设置textView的背景色

     * @param bgColor
     */
    var bgColor: Int
        get() = mBgColor
        set(bgColor) {
            this.mBgColor = bgColor
            invalidate()
        }

    var roundSize: Float
        get() = mRoundSize
        set(roundSize) {
            this.mRoundSize = roundSize
            invalidate()
        }

    var roundType: RoundType
        get() = mRoundType
        set(mRoundType) {
            this.mRoundType = mRoundType
            invalidate()
        }

    /**
     * 初始化
     */
    private fun init(attributeSet: AttributeSet) {
        val typedArray = context.obtainStyledAttributes(attributeSet, R.styleable.RoundTextView)
        mRoundSize = typedArray.getDimension(R.styleable.RoundTextView_roundSize, resources.getDimension(R.dimen.border_radius_normal))
        mBgColor = typedArray.getColor(R.styleable.RoundTextView_bgColor, 0)
        mRoundType = RoundType.values()[typedArray.getInt(R.styleable.RoundTextView_roundType, 0)]
        typedArray.recycle()

        gravity = Gravity.CENTER

    }


    override fun onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int) {
        super.onSizeChanged(w, h, oldw, oldh)
        rectF = RectF(0f, 0f, w.toFloat(), h.toFloat())
    }

    override fun onDraw(canvas: Canvas) {
        if (mBgColor == 0) {
            super.onDraw(canvas)
            return
        }

        mPaint.color = mBgColor
        mPaint.isAntiAlias = true
        canvas.drawRoundRect(rectF!!, mRoundSize, mRoundSize, mPaint)
        when (mRoundType) {
            RoundTextView.RoundType.ROUND_RECT -> {
            }
            RoundTextView.RoundType.ROUND_TOP -> {
                canvas.drawRect(0f, height - mRoundSize, mRoundSize, height.toFloat(), mPaint)
                canvas.drawRect(width - mRoundSize, height - mRoundSize, width.toFloat(), height.toFloat(), mPaint)
            }
            RoundTextView.RoundType.ROUND_BOTTOM -> {
                canvas.drawRect(0f, 0f, mRoundSize, mRoundSize, mPaint)
                canvas.drawRect(width - mRoundSize, 0f, width.toFloat(), mRoundSize, mPaint)
            }

            RoundTextView.RoundType.LEFT_BOTTOM -> {
                canvas.drawRect(0f, 0f, mRoundSize, mRoundSize, mPaint)
                canvas.drawRect(0f, 0f, width.toFloat(), mRoundSize, mPaint)
                canvas.drawRect(width - mRoundSize, height - mRoundSize, width.toFloat(), height.toFloat(), mPaint)
            }

            RoundTextView.RoundType.RIGHT_BOTTOM -> {
                canvas.drawRect(width - mRoundSize, 0f, width.toFloat(), mRoundSize, mPaint)
                canvas.drawRect(0f, 0f, width.toFloat(), mRoundSize, mPaint)
                canvas.drawRect(0f, height - mRoundSize, mRoundSize, height.toFloat(), mPaint)
            }
        }
        super.onDraw(canvas)
    }

    /**
     * 用于代码生成
     */
    class Builder(private val mContext: Context) {
        private var bgColor: Int = 0 //背景颜色
        private var roundSize: Float = 0.toFloat() //圆角的值
        private var textColor: Int = 0 //文本颜色
        private var textSize: Float = 0.toFloat() //文字大小
        private var textString: String? = null//文本
        private var roundType = RoundType.ROUND_RECT //圆角的类型

        fun setRoundSize(roundSize: Float): Builder {
            this.roundSize = roundSize
            return this
        }

        fun setRoundType(roundType: RoundType): Builder {
            this.roundType = roundType
            return this
        }

        fun setTextColor(textColor: Int): Builder {
            this.textColor = textColor
            return this
        }

        fun setTextString(text: String): Builder {
            this.textString = text
            return this
        }

        fun setBgColor(bgColor: Int): Builder {
            this.bgColor = bgColor
            return this
        }

        fun setTextSize(textSize: Float): Builder {
            this.textSize = textSize
            return this
        }

        fun build(): RoundTextView {
            val roundTextView = RoundTextView(mContext, null, 0)
            roundTextView.mRoundType = roundType
            roundTextView.mBgColor = bgColor
            roundTextView.mRoundSize = roundSize
            roundTextView.setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize)
            roundTextView.setTextColor(textColor)
            roundTextView.text = textString
            roundTextView.requestLayout()

            return roundTextView
        }
    }
}

属性

<declare-styleable name="RoundTextView">
    <attr name="roundSize" format="dimension|reference" />
    <!--背景色-->
    <attr name="bgColor" format="color" />
    <attr name="roundType" format="enum">
        <enum name="roundRect" value="0" />
        <enum name="roundTop" value="1" />
        <enum name="roundBottom" value="2" />
        <enum name="leftBottom" value="3" />
        <enum name="rightBottom" value="4" />
    </attr>
</declare-styleable>