Android自定義View繪製彩色圓弧
阿新 • • 發佈:2020-02-19
本文例項為大家分享了Android自定義View繪製彩色圓弧的具體程式碼,供大家參考,具體內容如下
效果如下:
自定義View程式碼如下:
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. * 漸變圓弧 */ public class GradualView extends View { private Context context; private Paint paint;//畫筆 private Paint paintFull;//實心圓畫筆 private Paint textPaint;//標識字畫筆 private Paint valuePaint;//移動小球畫筆 private int[] mColors;//漸變色陣列 private int centerX;//中心X private int centerY;//中心Y private int srcH;//控制元件高度 private float startAngle = 110;//圓弧起始角度 private float sweepAngle = 320;//圓弧所佔度數 private float airValue = 66; /** * 直接在程式碼中呼叫時,使用該函式 * * @param context */ public GradualView(Context context) { super(context); initData(context); } /** * 在xml中使用自定義view時,使用這個函式 * * @param context * @param attrs */ public GradualView(Context context,AttributeSet attrs) { super(context,attrs); initData(context); } /** * 可以由上一個函式中手動呼叫 * * @param context * @param atrrs * @param defStyle 自定義函式中的attrs表示view的屬性集,defStyle表示預設的屬性資源集的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,//草綠色 0xFFFFFF00,//黃色 0xFFFF6600,//橘色 0xFFFF0000,//紅色 0xFF660099,//紫色 }; Shader s = new SweepGradient(0,mColors,null); paint.setAntiAlias(true);//設定畫筆為無鋸齒 paint.setStrokeWidth(dip2px(context,14));//線寬 paint.setShader(s); paintFull = new Paint(Paint.ANTI_ALIAS_FLAG); paintFull.setStyle(Paint.Style.FILL_AND_STROKE); paintFull.setAntiAlias(true);//設定畫筆為無鋸齒 paintFull.setShader(s); textPaint = new Paint(Paint.ANTI_ALIAS_FLAG); textPaint.setTextSize(dip2px(context,22));//設定字型大小 textPaint.setColor(0xFFFFFFFF); valuePaint = new Paint(Paint.ANTI_ALIAS_FLAG); valuePaint.setAntiAlias(true);//設定畫筆為無鋸齒 } 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); //移動中心 canvas.translate(centerX,centerY); RectF oval = new RectF(); oval.left = -r;//左邊 oval.top = -r;//上邊 oval.right = r;//右邊 oval.bottom = r;//下邊 canvas.drawArc(oval,startAngle,sweepAngle,false,paint); //繪製圓弧 //繪製圓弧兩頭的小圓 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,paintFull); //小圓離球的距離 float range = r + dip2px(context,30); float ar = 12f; //畫周圍小球和數字 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,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,paintFull); canvas.drawText("100",ax3 - getTextW() * 7,ay3 + getTextH() / 2,textPaint); float ax4 = 0; float ay4 = -range; canvas.drawCircle(ax4,ay4,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,paintFull); canvas.drawText("200",ax5 + getTextW(),ay5 + getTextH() / 2,textPaint); float ax6 = range; float ay6 = 0; canvas.drawCircle(ax6,ay6,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,paintFull); canvas.drawText("500",ax7 + getTextW(),ay7 + getTextH() / 2,textPaint); //畫標識小球 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) {//此處有問題 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,4),paintFull); } /** * dip轉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); } /** * 獲取"正"的高度 * * @return */ private float getTextH() { Paint pFont = new Paint(); Rect rect = new Rect(); //返回包圍整個字串的最小的一個Rect區域 pFont.getTextBounds("正",1,rect); return rect.height(); } /** * 獲取"正"的寬度 * * @return */ private float getTextW() { Paint pFont = new Paint(); Rect rect = new Rect(); //返回包圍整個字串的最小的一個Rect區域 pFont.getTextBounds("正",rect); return rect.width(); } }
以上就是本文的全部內容,希望對大家的學習有所幫助,也希望大家多多支援我們。