Question

我正在研究android中的饼图。由于我不能使用像aChartEngine这样的库，我使用以下代码绘制饼图： -

public class Chart extends View {  
    private Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);  
    private float[] value_degree;  
    private String[] Title_value;
    RectF rectf = new RectF(50, 5, 200, 150); 
    Rect rect = new Rect(50, 5, 200, 150);
    float temp = 0;  

        public Chart(Context context, float[] values, String[] heading)
        {  
            super(context);  
            value_degree = new float[values.length]; 
            Title_value = new String[heading.length];
            for (int i = 0; i < values.length; i++)
            {  
                value_degree[i] = values[i];  
                Title_value[i] = heading[i];
            }  
    }  

    @Override  
    protected void onDraw(Canvas canvas) {  
    super.onDraw(canvas);  
    Random r;  

    int centerX = (rect.left + rect.right) / 2;
    int centerY = (rect.top + rect.bottom) / 2;
    int radius = (rect.right - rect.left) / 2;

    radius *= 0.5; // 1 will put the text in the border, 0 will put the text in the center. Play with this to set the distance of your text.

    for (int i = 0; i < value_degree.length; i++) 
    {  
        if (i == 0) 
        {  
            r = new Random();  
            int color = Color.argb(100, r.nextInt(256), r.nextInt(256),  
            r.nextInt(256));  
            paint.setColor(color);
            canvas.drawArc(rectf, temp, value_degree[i], true, paint);  

            paint.setColor(Color.BLACK); // set this to the text color.
            paint.setTextSize(12);
            /*paint.setTextAlign(Align.CENTER);
            */float medianAngle = (temp + (value_degree[i] / 2f)) * (float)Math.PI / 180f; // this angle will place the text in the center of the arc.
            canvas.drawText(Title_value[i], (float)(centerX + (radius * Math.cos(medianAngle))), (float)(centerY + (radius * Math.sin(medianAngle))), paint);

        } 
        else 
        {  
            temp += value_degree[i - 1];  
            r = new Random();  
            int color = Color.argb(255, r.nextInt(256), r.nextInt(256),  
            r.nextInt(256));  
            paint.setColor(color);  
            canvas.drawArc(rectf, temp, value_degree[i], true, paint);

            paint.setColor(Color.BLACK); // set this to the text color.
            paint.setTextSize(12);
            /*paint.setTextAlign(Align.CENTER);
            */float medianAngle = (temp + (value_degree[i] / 2f)) * (float)Math.PI / 180f; // this angle will place the text in the center of the arc.
            canvas.drawText(Title_value[i], (float)(centerX + (radius * Math.cos(medianAngle))), (float)(centerY + (radius * Math.sin(medianAngle))), paint);

        }  
    }  
    }    

}

从数据库传递浮点值和标题。现在我需要自己为每个切片分配颜色而不是随机。我怎么能这样做？或者请告诉我如何使用上面的代码为每个切片分配颜色值。

此外，我需要计算每个切片的百分比值并显示标题。怎么做到这一点？

如果有任何建议，请帮助我。

提前致谢。

如何在饼图中设置每个切片的颜色（非随机）？

0 个答案: