继续常规图的绘制研究，在这绘制了个环形图(Dount Chart),很简单，大圆套小圆就出来了。呵呵，照例先上猛照:
怎么样，效果还可以吧，实现代码很少，附上:
package com.xcl.chart;
/**
* Canvas练习
* 自已画环形图(Dount Chart)
*
* 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.RectF;
import android.util.DisplayMetrics;
import android.view.View;
public class PanelDountChart2 extends View{
private int ScrWidth,ScrHeight;
//演示用的百分比例,实际使用中，即为外部传入的比例参数
private final float arrPer[] = new float[]{20f,30f,10f,40f};
//RGB颜色数组
private final int arrColorRgb[][] = { {77, 83, 97},
{148, 159, 181},
{253, 180, 90},
{52, 194, 188}} ;
public PanelDountChart2(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){
//画布背景
canvas.drawColor(Color.WHITE);
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);
//画笔初始化
Paint PaintArc = new Paint();
Paint PaintLabel = new Paint();
PaintLabel.setColor(Color.WHITE);
PaintLabel.setTextSize(16);
//位置计算类
XChartCalc xcalc = new XChartCalc();
float Percentage = 0.0f;
float CurrPer = 0.0f;
int i= 0;
for(i=0; i<arrPer.length; i++)
{
//将百分比转换为饼图显示角度
Percentage = 360 * (arrPer[i]/ 100);
Percentage = (float)(Math.round(Percentage *100))/100;
//分配颜色
PaintArc.setARGB(255,arrColorRgb[i][0], arrColorRgb[i][1], arrColorRgb[i][2]);
//在饼图中显示所占比例
canvas.drawArc(arcRF0, CurrPer, Percentage, true, PaintArc);
//计算百分比标签
xcalc.CalcArcEndPointXY(cirX, cirY, radius - radius/2/2, CurrPer + Percentage/2);
//标识
canvas.drawText(Float.toString(arrPer[i])+"%",xcalc.getPosX(), xcalc.getPosY() ,PaintLabel);
//下次的起始角度
CurrPer += Percentage;
}
//画圆心
PaintArc.setColor(Color.WHITE);
canvas.drawCircle(cirX,cirY,radius/2,PaintArc);
}
}
就这很么点代码就搞定了。 所以说简单的图完全可以不用图表库的。
代码中用到的类，在我前面的例子中找即可。
Android Canvas练习(5)自已绘面积图(Area Chart)
MAIL: xcl_168@aliyun.com
BLOG: http://blog.csdn.net/xcl168