Android自定义View绘制彩色圆弧

来源：互联网发布：远方光电人工智能编辑：程序博客网时间：2024/05/16 03:54
效果如下：
自定义View代码如下：
package com.example.yan;import android.content.Context;import android.graphics.Canvas;import android.graphics.Paint;import android.graphics.Rect;import android.graphics.RectF;import android.graphics.Shader;import android.graphics.SweepGradient;import android.util.AttributeSet;import android.view.View;/** * Created by xiaoyanzi on 2016/3/18. * 渐变圆弧 */public class GradualView extends View {    private Context context;    private Paint paint;//画笔    private Paint paintFull;//实心圆画笔    private Paint textPaint;//标识字画笔    private Paint valuePaint;//移动小球画笔    private int[] mColors;//渐变色数组    private int centerX;//中心X    private int centerY;//中心Y    private int srcH;//控件高度    private float startAngle = 110;//圆弧起始角度    private float sweepAngle = 320;//圆弧所占度数    private float airValue = 66;    /**     * 直接在代码中调用时，使用该函数     *     * @param context     */    public GradualView(Context context) {        super(context);        initData(context);    }    /**     * 在xml中使用自定义view时，使用这个函数     *     * @param context     * @param attrs     */    public GradualView(Context context, AttributeSet attrs) {        super(context, attrs);        initData(context);    }    /**     * 可以由上一个函数中手动调用     *     * @param context     * @param atrrs     * @param defStyle 自定义函数中的attrs表示view的属性集，defStyle表示默认的属性资源集的id     */    public GradualView(Context context, AttributeSet atrrs, int defStyle) {        super(context, atrrs, defStyle);    }    /**     * 初始化     * @param context     */    private void initData(Context context) {        this.context = context;        paint = new Paint(Paint.ANTI_ALIAS_FLAG);        paint.setStyle(Paint.Style.STROKE);        mColors = new int[]{                0xFF660099,//紫色                0xFF330033,//褐色                0xFF99FF00,//草绿色                0xFFFFFF00,//黄色                0xFFFF6600,//橘色                0xFFFF0000,//红色                0xFF660099,//紫色        };        Shader s = new SweepGradient(0, 0, mColors, null);        paint.setAntiAlias(true);//设置画笔为无锯齿        paint.setStrokeWidth(dip2px(context, 14));//线宽        paint.setShader(s);        paintFull = new Paint(Paint.ANTI_ALIAS_FLAG);        paintFull.setStyle(Paint.Style.FILL_AND_STROKE);        paintFull.setAntiAlias(true);//设置画笔为无锯齿        paintFull.setShader(s);        textPaint = new Paint(Paint.ANTI_ALIAS_FLAG);        textPaint.setTextSize(dip2px(context, 22));//设置字体大小        textPaint.setColor(0xFFFFFFFF);        valuePaint = new Paint(Paint.ANTI_ALIAS_FLAG);        valuePaint.setAntiAlias(true);//设置画笔为无锯齿    }    public void setAirValue(float airValue) {        this.airValue = airValue;    }    @Override    protected void onSizeChanged(int w, int h, int oldw, int oldh) {        super.onSizeChanged(w, h, oldw, oldh);        srcH = h;        centerX = w / 2;        centerY = h / 2;    }    @Override    protected void onDraw(Canvas canvas) {        super.onDraw(canvas);        float r = srcH / 2 - paint.getStrokeWidth() * 0.5f - dip2px(context, 200);        //移动中心        canvas.translate(centerX, centerY);        RectF oval = new RectF();        oval.left = -r;//左边        oval.top = -r;//上边        oval.right = r;//右边        oval.bottom = r;//下边        canvas.drawArc(oval, startAngle, sweepAngle, false, paint);    //绘制圆弧        //绘制圆弧两头的小圆        float mr = dip2px(context, 7);        float x1 = (float) (-r * Math.sin((360 - sweepAngle) / 2 * Math.PI / 180));        float y1 = (float) (r * Math.cos((360 - sweepAngle) / 2 * Math.PI / 180));        canvas.drawCircle(x1, y1, mr, paintFull);        float x2 = (float) (r * Math.sin((360 - sweepAngle) / 2 * Math.PI / 180));        float y2 = (float) (r * Math.cos((360 - sweepAngle) / 2 * Math.PI / 180));        canvas.drawCircle(x2, y2, mr, paintFull);        //小圆离球的距离        float range = r + dip2px(context, 30);        float ar = 12f;        //画周围小球和数字        float ax1 = (float) (-range * Math.sin(45 * Math.PI / 180));        float ay1 = (float) (range * Math.cos(45 * Math.PI / 180));        canvas.drawCircle(ax1, ay1, ar, paintFull);        canvas.drawText("0", ax1 - getTextW() * 3, ay1 + getTextH() / 2, textPaint);        float ax2 = -range;        float ay2 = 0;        canvas.drawCircle(ax2, ay2, ar, paintFull);        canvas.drawText("50", ax2 - getTextW() * 5, ay2 + getTextH() / 2, textPaint);        float ax3 = (float) (-range * Math.sin(45 * Math.PI / 180));        float ay3 = (float) (-range * Math.cos(45 * Math.PI / 180));        canvas.drawCircle(ax3, ay3, ar, paintFull);        canvas.drawText("100", ax3 - getTextW() * 7, ay3 + getTextH() / 2, textPaint);        float ax4 = 0;        float ay4 = -range;        canvas.drawCircle(ax4, ay4, ar, paintFull);        canvas.drawText("150", ax4 - getTextW() * 3, ay4 - getTextH(), textPaint);        float ax5 = (float) (range * Math.sin(45 * Math.PI / 180));        float ay5 = (float) (-range * Math.cos(45 * Math.PI / 180));        canvas.drawCircle(ax5, ay5, ar, paintFull);        canvas.drawText("200", ax5 + getTextW(), ay5 + getTextH() / 2, textPaint);        float ax6 = range;        float ay6 = 0;        canvas.drawCircle(ax6, ay6, ar, paintFull);        canvas.drawText("300", ax6 + getTextW(), ay6 + getTextH() / 2, textPaint);        float ax7 = (float) (range * Math.sin(45 * Math.PI / 180));        float ay7 = (float) (range * Math.cos(45 * Math.PI / 180));        canvas.drawCircle(ax7, ay7, ar, paintFull);        canvas.drawText("500", ax7 + getTextW(), ay7 + getTextH() / 2, textPaint);        //画标识小球        valuePaint.setColor(0xFFFFFFFF);        float cx;        float cy;        if (airValue >= 0 && airValue <= 50) {            cx = (float) (-r * Math.cos((45 - airValue * 0.9) * Math.PI / 180));            cy = (float) (r * Math.sin((45 - airValue * 0.9) * Math.PI / 180));        } else if (airValue > 50 && airValue <= 150) {            cx = (float) (-r * Math.cos((airValue * 0.9 - 45) * Math.PI / 180));            cy = (float) (-r * Math.sin((airValue * 0.9 - 45) * Math.PI / 180));        } else if (airValue > 150 && airValue <= 200) {            cx = (float) (-r * Math.cos((airValue * 0.9 - 45) * Math.PI / 180));            cy = (float) (-r * Math.sin((airValue * 0.9 - 45) * Math.PI / 180));        } else if (airValue > 200 && airValue <= 300) {            cx = (float) (-r * Math.cos((airValue * 0.45 + 45) * Math.PI / 180));            cy = (float) (-r * Math.sin((airValue * 0.45 + 45) * Math.PI / 180));        } else if (airValue > 300 && airValue <= 500) {//此处有问题            cx = (float) (r * Math.cos(((airValue - 300) * 0.225) * Math.PI / 180));            cy = (float) (r * Math.sin(((airValue - 300) * 0.225) * Math.PI / 180));        } else {            cx = (float) (-r * Math.cos(45 * Math.PI / 180));            cy = (float) (r * Math.sin(45 * Math.PI / 180));        }        canvas.drawCircle(cx, cy, dip2px(context, 11), valuePaint);        canvas.drawCircle(cx, cy, dip2px(context, 4), paintFull);    }    /**     * dip转px     * @param context     * @param dpValue     * @return     */    private int dip2px(Context context, float dpValue) {        final float scale = context.getResources().getDisplayMetrics().density;        return (int) (dpValue * scale + 0.5f);    }    /**     * 获取"正"的高度     *     * @return     */    private float getTextH() {        Paint pFont = new Paint();        Rect rect = new Rect();        //返回包围整个字符串的最小的一个Rect区域        pFont.getTextBounds("正", 0, 1, rect);        return rect.height();    }    /**     * 获取"正"的宽度     *     * @return     */    private float getTextW() {        Paint pFont = new Paint();        Rect rect = new Rect();        //返回包围整个字符串的最小的一个Rect区域        pFont.getTextBounds("正", 0, 1, rect);        return rect.width();    }}
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