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Android自定义控件实现饼状图 Android自定义控件实现饼状图

王世晖 人气:0

本文实现一个如图所示的控件,包括两部分,左边的饼状图和中间的两个小方块,及右边的两行文字

实现起来比较简单,只是一些绘图API的调用

核心代码在onDraw函数里边,对静态控件进行绘制即可

@Override
protected void onDraw(Canvas canvas) {
 super.onDraw(canvas);
 /**
 * 饼状图的x坐标
 */
 float centreX= getWidth()/5;
 /**
 * 饼状图的y坐标
 */
 float centreY= getHeight()/2;
 /**
 * 文字的大小
 */
 float textSize=getHeight()/7;
 float width=(float)getWidth();
 float height=(float)getHeight();
 /**
 * 中间小正方形边长的一半
 */
 float halfSmallRec =((float)getHeight())*3/70;
 percent =((float) mBigBallNumber)/(mBigBallNumber + mSmallBallNumber);
 /**
 * 求饼状图的半径
 */
 radius= Math.min(getWidth() * 1 / 8, getHeight() * 10 / 35);
 /**
 * 构建一个正方形,饼状图是这个正方形的内切圆
 */
 rectf=new RectF((int)(centreX-radius),(int)(centreY-radius),(int)(centreX+radius),(int)(centreY+radius));
 /**
 * 设置饼状图画笔的颜色,先绘制大球占的比例
 */
 piePaint.setColor(mBigBallColor);
 /* The arc is drawn clockwise. An angle of 0 degrees correspond to the
 * geometric angle of 0 degrees (3 o'clock on a watch.)*/
 /* drawArc(RectF oval, float startAngle, float sweepAngle, boolean useCenter,Paint paint)*/
 /**
 * 绘制大球的扇形图,float startAngle起始角度的0度的位置在3点钟方向
 * 因此大球的扇形图要从12点钟开始绘制,所以起始角度为270度
 */
 canvas.drawArc(rectf, 270, 360 * percent, true, piePaint);
 /**
 * 换种颜色,开始绘制小球占的饼状图
 */
 piePaint.setColor(mSmallBallColor);
 /**
 * 起始角度就是12点钟加上360度乘以大球占的比例,12点钟转换为起始角度为270度
 */
 canvas.drawArc(rectf, 270 + 360 * percent, 360 - 360 * percent, true, piePaint);
 颜色更改为大球的颜色*/
 piePaint.setColor(mBigBallColor);
 /**
 * 绘制上边的小方块,也就是大球的方块
 */
 canvas.drawRect(width * 2 / 5 - halfSmallRec, height* 23/ 60 - halfSmallRec, width * 2 / 5 + halfSmallRec, height *23/ 60 + halfSmallRec, piePaint);
 /**
 * 更改画笔颜色为小球颜色
 */
 piePaint.setColor(mSmallBallColor);
 /**
 * 绘制下边的小方块即小球的小方块
 */
 canvas.drawRect(width * 2 / 5 - halfSmallRec, height * 37 / 60 - halfSmallRec, width * 2 / 5 + halfSmallRec, height * 37 / 60 + halfSmallRec, piePaint);
 /**
 * 开始绘制文字,先设置文字颜色
 */
 textPaint.setColor(getResources().getColor(typedValue.resourceId));
 /**
 * 设置问题大小
 */
 textPaint.setTextSize(textSize);
 /**
 * 大球数量
 */
 String strBig = strBigBallName + mBigBallNumber;
 /**
 * 测量文字宽度
 */
 float textBigWidth =textPaint.measureText(strBig);
 Paint.FontMetrics fontMetrics=textPaint.getFontMetrics();
 /**
 * 绘制上边大球数量
 */
 canvas.drawText(strBig, width * 9 / 20 + textBigWidth / 2, height *23/ 60 - fontMetrics.top / 3, textPaint);
 /**
 * 小球数量
 */
 String strSmall = strSmallBallName + mSmallBallNumber;
 /**
 * 测量文字宽度
 */
 float textUnderWidth=textPaint.measureText(strSmall);
 /**
 * 绘制下边的小球数量
 */
 canvas.drawText(strSmall,width*9/20+textUnderWidth/2,height*37/60-fontMetrics.top/3,textPaint);
 /**
 * 更改画笔颜色,开始绘制百分比
 */
 textPaint.setColor(getResources().getColor(R.color.half_transparent));
 String strBigPercent =" ("+ mPercentBigBall +")";
 /**
 * 测量大球百分比文字宽度
 */
 float bigPercent =textPaint.measureText(strBigPercent);
 /**drawText(String text, float x, float y, Paint paint)
 * 绘制文字的API,四个参数分别是文字内容,起始绘制x坐标,起始绘制y坐标,画笔
 * 以为设置了居中绘制,因此穿进去的xy坐标为文字的中心点
 */
 canvas.drawText(strBigPercent, width * 9 / 20+ textBigWidth + bigPercent /2, height*23 / 60-fontMetrics.top*1/3, textPaint);
 /**
 * 同样的道理绘制小球的百分比
 */
 String strSmallPercent =" ("+ mPercentSmallBall +")";
 float smallPercent =textPaint.measureText(strSmallPercent);
 canvas.drawText(strSmallPercent,width*9/20+textUnderWidth+ smallPercent /2,height*37/60-fontMetrics.top/3,textPaint);
}

Canvas 绘制文本时,使用FontMetrics对象,计算位置的坐标。参考:使用FontMetrics对象计算位置坐标

设置文字绘制以中心为起点开始绘制

textPaint.setTextAlign(Paint.Align.CENTER);

x的坐标好计算,y坐标需要按需使用FontMetrics几个属性即可

完整代码如下:

public class PieHalfView extends View {
 /**
 * 左边饼状图的画笔
 */
 private Paint piePaint;
 /**
 * 右边文字的画笔
 */
 private Paint textPaint;
 /**
 * 饼状图的半径
 */
 private float radius;
 private RectF rectf;
 /**
 * 饼状图中第一个扇形占整个圆的比例
 */
 private float percent;
 /**
 * 深浅两种颜色
 */
 private int mBigBallColor, mSmallBallColor;
 /**
 * 大小球的数量
 */
 private int mBigBallNumber;
 private int mSmallBallNumber;
 /**
 * 大小球所占的百分比
 */
 private String mPercentBigBall;
 private String mPercentSmallBall;
 /**
 * 动态获取属性
 */
 private TypedValue typedValue;
 /**
 * 中间的文字信息
 */
 private String strBigBallName;
 private String strSmallBallName;
 
 public PieHalfView(Context context) {
 super(context);
 init(context);
 }
 
 public PieHalfView(Context context, AttributeSet attrs) {
 super(context, attrs);
 init(context);
 }
 
 public PieHalfView(Context context, AttributeSet attrs, int defStyleAttr) {
 super(context, attrs, defStyleAttr);
 init(context);
 }
 private void init(Context context) {
 /**
 * 设置饼状图画笔
 */
 piePaint =new Paint();
 piePaint.setAntiAlias(true);
 piePaint.setStyle(Paint.Style.FILL);
 /**
 * 设置文字画笔
 */
 textPaint=new Paint();
 textPaint.setStyle(Paint.Style.STROKE);
 textPaint.setAntiAlias(true);
 textPaint.setTextAlign(Paint.Align.CENTER);
 /**
 * 下边设置一些默认的值,如果调用者没有传值进来的话,用这些默认值
 */
 mBigBallColor = 0xFF9CCA5D;
 mSmallBallColor =0xFF5F7048;
 /*TypedValue:Container for a dynamically typed data value. Primarily used with Resources for holding resource values.*/
 typedValue=new TypedValue();
 context.getTheme().resolveAttribute(R.attr.maintextclor,typedValue,true);
 mBigBallNumber =1;
 mSmallBallNumber =3;
 mPercentBigBall ="40%";
 mPercentSmallBall ="60%";
 strBigBallName =getResources().getString(R.string.big);
 strSmallBallName =getResources().getString(R.string.small);
 }
 
 @Override
 protected void onDraw(Canvas canvas) {
 super.onDraw(canvas);
 /**
 * 饼状图的x坐标
 */
 float centreX= getWidth()/5;
 /**
 * 饼状图的y坐标
 */
 float centreY= getHeight()/2;
 /**
 * 文字的大小
 */
 float textSize=getHeight()/7;
 float width=(float)getWidth();
 float height=(float)getHeight();
 /**
 * 中间小正方形边长的一半
 */
 float halfSmallRec =((float)getHeight())*3/70;
 percent =((float) mBigBallNumber)/(mBigBallNumber + mSmallBallNumber);
 /**
 * 求饼状图的半径
 */
 radius= Math.min(getWidth() * 1 / 8, getHeight() * 10 / 35);
 /**
 * 构建一个正方形,饼状图是这个正方形的内切圆
 */
 rectf=new RectF((int)(centreX-radius),(int)(centreY-radius),(int)(centreX+radius),(int)(centreY+radius));
 /**
 * 设置饼状图画笔的颜色,先绘制大球占的比例
 */
 piePaint.setColor(mBigBallColor);
 /* The arc is drawn clockwise. An angle of 0 degrees correspond to the
 * geometric angle of 0 degrees (3 o'clock on a watch.)*/
 /* drawArc(RectF oval, float startAngle, float sweepAngle, boolean useCenter,Paint paint)*/
 /* 绘制大球的扇形图,float startAngle起始角度的0度的位置在3点钟方向
 * 因此大球的扇形图要从12点钟开始绘制,所以起始角度为270度*/
 canvas.drawArc(rectf, 270, 360 * percent, true, piePaint);
 /**
 * 换种颜色,开始绘制小球占的饼状图
 */
 piePaint.setColor(mSmallBallColor);
 /**
 * 起始角度就是12点钟加上360度乘以大球占的比例,12点钟转换为起始角度为270度
 */
 canvas.drawArc(rectf, 270 + 360 * percent, 360 - 360 * percent, true, piePaint);
 /**
 * 颜色更改为大球的颜色*/
  piePaint.setColor(mBigBallColor);
 /**
 * 绘制上边的小方块,也就是大球的方块
 */
 canvas.drawRect(width * 2 / 5 - halfSmallRec, height* 23/ 60 - halfSmallRec, width * 2 / 5 + halfSmallRec, height *23/ 60 + halfSmallRec, piePaint);
 /**
 * 更改画笔颜色为小球颜色
 */
 piePaint.setColor(mSmallBallColor);
 /**
 * 绘制下边的小方块即小球的小方块
 */
 canvas.drawRect(width * 2 / 5 - halfSmallRec, height * 37 / 60 - halfSmallRec, width * 2 / 5 + halfSmallRec, height * 37 / 60 + halfSmallRec, piePaint);
 /**
 * 开始绘制文字,先设置文字颜色
 */
 textPaint.setColor(getResources().getColor(typedValue.resourceId));
 /**
 * 设置问题大小
 */
 textPaint.setTextSize(textSize);
 /**
 * 大球数量
 */
 String strBig = strBigBallName + mBigBallNumber;
 /**
 * 测量文字宽度
 */
 float textBigWidth =textPaint.measureText(strBig);
 Paint.FontMetrics fontMetrics=textPaint.getFontMetrics();
 /**
 * 绘制上边大球数量
 */
 canvas.drawText(strBig, width * 9 / 20 + textBigWidth / 2, height *23/ 60 - fontMetrics.top / 3, textPaint);
 /**
 * 小球数量
 */
 String strSmall = strSmallBallName + mSmallBallNumber;
 /**
 * 测量文字宽度
 */
 float textUnderWidth=textPaint.measureText(strSmall);
 /**
 * 绘制下边的小球数量
 */
 canvas.drawText(strSmall,width*9/20+textUnderWidth/2,height*37/60-fontMetrics.top/3,textPaint);
 /**
 * 更改画笔颜色,开始绘制百分比
 */
 textPaint.setColor(getResources().getColor(R.color.half_transparent));
 String strBigPercent =" ("+ mPercentBigBall +")";
 /**
 * 测量大球百分比文字宽度*/
 float bigPercent =textPaint.measureText(strBigPercent);
 /** drawText(String text, float x, float y, Paint paint)
 * 绘制文字的API,四个参数分别是文字内容,起始绘制x坐标,起始绘制y坐标,画笔
 * 以为设置了居中绘制,因此穿进去的xy坐标为文字的中心点
 */
 canvas.drawText(strBigPercent, width * 9 / 20+ textBigWidth + bigPercent /2, height*23 / 60-fontMetrics.top*1/3, textPaint);
 /*
 * 同样的道理绘制小球的百分比
 */
 String strSmallPercent =" ("+ mPercentSmallBall +")";
 float smallPercent =textPaint.measureText(strSmallPercent);
 canvas.drawText(strSmallPercent,width*9/20+textUnderWidth+ smallPercent /2,height*37/60-fontMetrics.top/3,textPaint);
 }
 public void setPercent(float percent1){
 this.percent =percent1;
 invalidate();
 }
 public void setColor(int mBigBallColor,int mSmallBallColor){
 this.mBigBallColor =mBigBallColor;
 this.mSmallBallColor =mSmallBallColor;
 invalidate();
 }
 
 public void setOverRunner(String bigPecent, String smallPercent, int big, int small,
 int bigColor, int smallColor){
 this.mPercentBigBall = bigPecent;
 this.mPercentSmallBall = smallPercent;
 this.mBigBallNumber = big;
 this.mSmallBallNumber = small;
 this.mBigBallColor = bigColor;
 this.mSmallBallColor = smallColor;
 invalidate();
 }
}

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