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DuosDuo
Asked:2020-08-20 02:24:57 +0000 UTC2020-08-20 02:24:57 +0000 UTC

绕过画布的角落

  • 772

有这样一个循环

public class PieChartView extends View {

    private final static String[] RColors = {"#448c9b", "#789a98", "#a4a795", "#ac6226", "#ef3c5e", "#b17170", "#9a9a82", "#bda763"};

    private RectF rec;
    private Paint p = new Paint();
    private String[][] data = {
            {"Facebook", "20"},
            {"Twitter", "20"},
            {"Whats app", "20"},
            {"Pinterest", "20"},
            {"Baby App", "20"}
    };
    private int d = 0;
    private float textSize = 20f;

    //========================
    public PieChartView(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    //========================
    public PieChartView(Context ctx){super(ctx);}

    //========================
    @Override
    public void onSizeChanged(int nw, int nh, int ow, int oh){
        super.onSizeChanged(nw, nh, ow, oh);
        d = nw>nh?nh:nw;
        rec = new RectF(0, 0, d, d);
        p.setFlags(Paint.ANTI_ALIAS_FLAG);
    }

    //========================
    public void setTextSize(float size){textSize=size;}

    //========================
    /**Set data to be shown in pie chart view
     * @param dList ArrayList of Object[], 1st element will contain the name, 2nd the percentage (int)
     */
    public void setData(ArrayList<Object[]> dList){
        data = new String[dList.size()][2];
        int i=0;
        for(Object[] op:dList){
            data[i++] = new String[]{op[0]+"",op[1]+""};
        }
    }

    //========================
    @Override
    public void onDraw(Canvas c){

        int size = data.length;
        int sa=0, ea=0, ci=0;
        //== draw arc
        for(int i=0;i<size;i++){
            int perc = Integer.parseInt(data[i][1]);
            int pdeg = (perc*360)/100;
            ea = sa+pdeg;
            p.setColor(Color.parseColor(RColors[ci++]));
            if(ci==RColors.length)
                ci=0;
            c.drawArc(rec, sa+3, pdeg-2, true, p);
            sa = ea;
        }

        //== draw circle in center
        p.setColor(Color.WHITE);
        c.drawCircle(rec.right/2, rec.bottom/2, (int)(0.8*(d/2)) , p);

        //== write text
        p.setColor(Color.BLACK);
        p.setFakeBoldText(true);
        p.setTextSize(textSize);
        sa=0;ea=0;ci=0;
        double ra = 0; // Radian angle
        for(int i=0;i<size;i++){
            p.setColor(Color.parseColor(RColors[ci++]));
            if(ci==RColors.length)
                ci=0;
            int perc = Integer.parseInt(data[i][1]);
            int pdeg = (perc*360)/100;
            ea = sa+pdeg; //== in degrees
            ra = (sa+pdeg/2)*Math.PI/180;
            int x = (int)(rec.right/2+(((rec.right/2)*.5)*Math.cos(ra)));
            int y = (int)(rec.right/2+(((rec.right/2)*.5)*Math.sin(ra)));
            String text = data[i][0];
            c.drawText(text, x-p.measureText(text)/2, y, p);
            text = data[i][1]+"%";
            c.drawText(text, x-p.measureText(text)/2, y-p.ascent()+p.descent(), p);
            sa = ea;
        }
    }
}

结果 在此处输入图像描述

Canvas 专家的问题，您如何制作相同的视图，但只能使线条的角落变圆（在红色部分，它大致显示了如何圆角），当然，希望能够控制四舍五入的程度。 在此处输入图像描述

java

1 个回答

  1. Best Answer

    弄成这样。如果你有什么要补充的，那么欢迎！

    class Data(
    val color: Int,
    val percent: Float
)

class PieChart : View {
    private val paint = Paint()
    private val tPaint = Paint()
    private var oval = RectF()
    private var demo: Boolean = false

    var lineOffset: Int = 0
    var startAngle: Float = 0F
    set(value) {
        field = value
        invalidate()
    }

    var descriptionTextSize: Float = 14F
    set(value) {
        field = value
        initPaintByText()
        invalidate()
    }

    var description: String = "Test description"
    set(value) {
        field = value
        invalidate()
    }

    var data: List<Data> = listOf()
    set(value) {
        field = value
        invalidate()
    }

    constructor(context: Context, attrs: AttributeSet) : super(context, attrs) {
        initAttrs(context = context, attrs = attrs)
        initStart()
    }

    constructor(context: Context?) : super(context) {
        initStart()
    }

    init {
        initPaintByText()
        initPaint()
    }

    private fun initAttrs( context: Context, attrs: AttributeSet) {
        val a = context.theme.obtainStyledAttributes(attrs, R.styleable.PieChart, 0, 0)
        try {
            demo = a.getBoolean(R.styleable.PieChart_demo, false)
            lineOffset = a.getDimensionPixelOffset(R.styleable.PieChart_lineOffset, 0)
            description = a.getString(R.styleable.PieChart_description) ?: ""
            startAngle = a.getFloat(R.styleable.PieChart_startAngle, 0F)

            descriptionTextSize = a.getDimensionPixelOffset(R.styleable.PieChart_descriptionTextSize, 14).toFloat()
        } finally {
            a.recycle()
        }
    }

    private fun initPaint(){
        paint.isAntiAlias = true
        paint.strokeWidth = 30f
        paint.strokeCap = Paint.Cap.ROUND
        paint.style = Paint.Style.STROKE
    }

    private fun initPaintByText() {
        tPaint.color = Color.BLACK
        tPaint.isFakeBoldText = true
        tPaint.textSize = descriptionTextSize
    }

    private fun initStart(){
        if (demo) {
            data = listOf(Data(Color.GREEN, 45F), Data(Color.BLUE, 35F), Data(Color.RED, 20F))
        }
        initPaint()
        initPaintByText()
    }

    public override fun onDraw(canvas: Canvas) {
        val width = width.toFloat()
        val height = height.toFloat()
        val radius: Float
        radius = if (width > height) {
            height / 3
        } else {
            width / 3
        }

        val centerX = width / 2
        val centerY = height / 1.6f
        val left = centerX - radius
        val top = centerY - radius
        val right = centerX + radius
        val bottom = centerY + radius

        oval[left, top, right] = bottom

        var mAngle: Float = startAngle

        for ((index, item) in data.withIndex()) {
            paint.color = item.color
            val pInAngle = item.percent * 3.6F
            val sAngle = pInAngle - (lineOffset)
            canvas.drawArc(oval, mAngle, sAngle, false, paint)

            mAngle += lineOffset + sAngle
        }
    }
}

    在此处输入图像描述

    • 1

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