Android中使用Canvas繪制南丁格爾玫瑰圖(Nightingale rose diagram)

南丁格爾玫瑰圖 在常規圖表中實在很驚艷，但我初看沒看懂，一查原來南丁格爾這麼偉大，確實值得尊敬。

再仔細研究了下這種圖的構成，發現原來就是把柱形圖的柱形換成了扇形圖的半徑來表示，當然，變種有好多，我這只是說我理解的這種。

知道了其構成方式後就好實現了，依傳入參數個數決定其扇形角度，依百分比決定其扇形的半徑長度，然後就一切都水到渠成了。

漂亮的美圖獻上:

附上實現代碼:

package com.xcl.chart;


/**
 * Canvas練習 
 * 	 自已畫南丁格爾玫瑰圖(Nightingale rose diagram)
 *   
 * author:xiongchuanliang
 * date:2014-4-12
 */


import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.graphics.RectF;
import android.util.DisplayMetrics;
import android.view.View;

public class PanelRoseChart extends View{
	
	private int ScrWidth,ScrHeight;	
	
	 //演示用的百分比例,實際使用中，即為外部傳入的比例參數 
	private final float arrPer[] = new float[]{40f,50f,60f,35f,70f,80f,90f}; 
	//演示用標簽
	private final String arrPerLabel[] = new String[]{"PostgreSQL","Sybase","DB2","國產及其它","MySQL","Ms Sql","Oracle"}; 
	//RGB顏色數組
	private final int arrColorRgb[][] = { {77, 83, 97}, 
							       {148, 159, 181}, 
							       {253, 180, 90},
							       {52, 194, 188},
							       {39, 51, 72},
							       {255, 135, 195},
							       {215, 124, 124}} ;
	
	
public PanelRoseChart(Context context) {
		super(context);
		// TODO Auto-generated constructor stub
		
		//屏幕信息
		DisplayMetrics dm = getResources().getDisplayMetrics();
		ScrHeight = dm.heightPixels;
		ScrWidth = dm.widthPixels;
	}

	
	public void onDraw(Canvas canvas){
		//畫布背景
		canvas.drawColor(Color.BLACK);		     
     
    float cirX = ScrWidth / 2; 
    float cirY = ScrHeight / 3 ; 
    float radius = ScrHeight / 5 ;//150; 
                 
    float arcLeft = cirX - radius; 
    float arcTop = cirY - radius ; 
    float arcRight = cirX + radius ; 
    float arcBottom = cirY + radius ; 
    RectF arcRF0 = new RectF(arcLeft ,arcTop,arcRight,arcBottom);  
    
    //畫筆初始化
		Paint PaintArc = new Paint(); 		
		Paint PaintLabel = new Paint(); 
		PaintLabel.setColor(Color.WHITE);
		PaintLabel.setTextSize(16);     
		
		PaintLabel.setAntiAlias(true);
		PaintArc.setAntiAlias(true);
    //位置計算類 
    XChartCalc xcalc = new XChartCalc();	
		
    float Percentage = 0.0f;
 		float CurrPer = 0.0f;
 		float NewRaidus = 0.0f;
		int i= 0; 
		
		 //將百分比轉換為扇形半徑長度
		Percentage = 360 / arrPer.length;
		Percentage = (float)(Math.round(Percentage *100))/100; 
		
    for(i=0; i<arrPer.length; i++)  
    { 
      //將百分比轉換為新扇區的半徑 
      NewRaidus = radius * (arrPer[i]/ 100); 
      NewRaidus = (float)(Math.round(NewRaidus *100))/100; 
      
      float NewarcLeft = cirX - NewRaidus; 
      float NewarcTop = cirY - NewRaidus ; 
      float NewarcRight = cirX + NewRaidus ; 
      float NewarcBottom = cirY + NewRaidus ; 
      RectF NewarcRF = new RectF(NewarcLeft ,NewarcTop,NewarcRight,NewarcBottom);  
            
      //分配顏色      
      PaintArc.setARGB(255,arrColorRgb[i][0], arrColorRgb[i][1], arrColorRgb[i][2]);
        
      //在餅圖中顯示所占比例 
      canvas.drawArc(NewarcRF, CurrPer, Percentage, true, PaintArc);         
      //計算百分比標簽
      xcalc.CalcArcEndPointXY(cirX, cirY, radius - radius/2/2, CurrPer + Percentage/2); 	
			//標識
		  canvas.drawText(arrPerLabel[i],xcalc.getPosX(), xcalc.getPosY() ,PaintLabel);		  
      //下次的起始角度 
      CurrPer += Percentage; 
    } 
    //外環
    PaintLabel.setStyle(Style.STROKE);
    PaintLabel.setColor(Color.GREEN);
    canvas.drawCircle(cirX,cirY,radius,PaintLabel); 

    canvas.drawText("author:xiongchuanliang", 10, ScrHeight - 200, PaintLabel);
    		
	}

}

代碼實現起來很容易，但這種圖的設計創意確實非常好。 歎服。

一定要附上南丁格爾維基百科的鏈接:      http://zh.wikipedia.org/wiki/%E5%BC%97%E7%BE%85%E5%80%AB%E6%96%AF%C2%B7%E5%8D%97%E4%B8%81%E6%A0%BC%E7%88%BE

感興趣的可以看看。