安卓简单绘制直方图思路

最近看了看HenCoder Android 开发进阶：自定义 View 1-1 绘制基础，作者讲的很全面，受益匪浅，顺手写了下常用Drawxxx()方法，练习了一下，以免忘记了。

这里说一下比价复杂的直方图，虽然很多第三方可以直接拿来用，但是我还是自己随便写了个Demo，知其所以然。

代码很简单：

public class Practice10HistogramView extends View {
    Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG);
    private float interval = 25;
    private float perWidth = 100;

    public Practice10HistogramView(Context context) {
        super(context);
    }

    public Practice10HistogramView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public Practice10HistogramView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
//        综合练习
//        练习内容：使用各种 Canvas.drawXXX() 方法画直方图

        RectF rectF1 = new RectF(100 + 1 * interval + 0 * perWidth,600 - 5,100 + 1 * perWidth + 1 * interval,600);
        RectF rectF2 = new RectF(100 + 2 * interval + 1 * perWidth,600 - 30,100 + 2 * perWidth + 2 * interval,600);
        RectF rectF3 = new RectF(100 + 3 * interval + 2 * perWidth,600 - 30,100 + 3 * perWidth + 3 * interval,600);
        RectF rectF4 = new RectF(100 + 4 * interval + 3 * perWidth,600 - 200,100 + 4 * perWidth + 4 * interval,600);
        RectF rectF5 = new RectF(100 + 5 * interval + 4 * perWidth,600 - 300,100 + 5 * perWidth + 5 * interval,600);
        RectF rectF6 = new RectF(100 + 6 * interval + 5 * perWidth,600 - 450,100 + 6 * perWidth + 6 * interval,600);
        RectF rectF7 = new RectF(100 + 7 * interval + 6 * perWidth,600 - 180,100 + 7 * perWidth + 7 * interval,600);
        paint.setColor(Color.GREEN);
        paint.setStyle(Paint.Style.FILL);

        canvas.drawRect(rectF1,paint);
        canvas.drawRect(rectF2,paint);
        canvas.drawRect(rectF3,paint);
        canvas.drawRect(rectF4,paint);
        canvas.drawRect(rectF5,paint);
        canvas.drawRect(rectF6,paint);
        canvas.drawRect(rectF7,paint);
        paint.setColor(Color.WHITE);
        canvas.drawLines(new float[]{100,20,100,600,100,600,1000,600},paint);

        paint.setTextSize(18);
        canvas.drawText("Froyo",100 + 1 * interval + 0.5f * perWidth,620,paint);
        canvas.drawText("GB",100 + 2 * interval + 1.5f * perWidth,620,paint);
        canvas.drawText("ICS",100 + 3 * interval + 2.5f * perWidth,620,paint);
        canvas.drawText("JB",100 + 4 * interval + 3.5f * perWidth,620,paint);
        canvas.drawText("KitKat",100 + 5 * interval + 4.5f * perWidth,620,paint);
        canvas.drawText("L",100 + 6 * interval + 5.5f * perWidth,620,paint);
        canvas.drawText("M",100 + 7 * interval + 6.5f * perWidth,620,paint);

        paint.setTextSize(30);
        canvas.drawText("直方图",500,700,paint);





    }

具体实现效果如下：

上面是效果图，下面是代码具体实现的图。

安卓简单绘制直方图思路

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