本文实例为大家分享了Android自定义控件实现雷达图的具体代码，供大家参考，具体内容如下
学习了大神的源代码（奈何不知大神的博客地址），觉得必须记录一下，方便以后再次学习。
效果如图所示：
1.自定义雷达图控件：
public class MyPolygonView extends View {
//-------------我们必须给的模拟数据-------------
//n边形
private int n = 6;
//每个角对应的文字
private String[] text = new String[]{"语文", "数学", "英语", "生物", "化学","物理"};
//区域等级，值不能超过n边形的个数（每个角对应的值到达的层数）
private int[] area = new int[]{3,3,2,2,3,2};
//-------------View相关-------------
//View自身的宽和高
private int mHeight;
private int mWidth;
//-------------画笔相关-------------
//边框的画笔
private Paint borderPaint;
//文字的画笔
private Paint textPaint;
//区域的画笔
private Paint areaPaint;
//-------------多边形相关-------------
//n边形个数
private int num = 4;
//两个多边形之间的半径
private int r = 60;
//n边形顶点坐标
private float x, y;
//n边形角度
private float angle = (float) ((2 * Math.PI) / n);
//文字与边框的边距等级，值越大边距越小（文字与边框的距离）
private int textAlign = 5;
//-------------颜色相关-------------
//边框颜色（整个n边型的区域颜色）
private int mColor = getResources().getColor(R.color.app_polygon);
//文字颜色
private int textColor = getResources().getColor(R.color.app_black);
//区域颜色(整个连线的颜色)
private int strengthColor = Color.parseColor("#f9c172");
public MyPolygonView(Context context) {
super(context);
}
public MyPolygonView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public MyPolygonView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
mWidth = w;
mHeight = h;
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//初始化画笔
initPaint();
//画布移到中心点
canvas.translate(mWidth / 2, mHeight / 2);
//画n边形
drawPolygon(canvas);
//画n边形的中点到顶点的线
drawLine(canvas);
//画文字
drawText(canvas);
//画蓝色区域
drawArea(canvas);
}
/**
* 初始化画笔
*/
private void initPaint() {
//边框画笔
borderPaint = new Paint();
borderPaint.setAntiAlias(true);
borderPaint.setStyle(Paint.Style.FILL_AND_STROKE);
borderPaint.setColor(mColor);
borderPaint.setStrokeWidth(3);
//文字画笔
textPaint = new Paint();
textPaint.setTextSize(30);
textPaint.setColor(textColor);
textPaint.setAntiAlias(true);
//区域画笔
areaPaint = new Paint();
areaPaint.setStrokeWidth(5);
areaPaint.setColor(strengthColor);
areaPaint.setAntiAlias(true);
areaPaint.setStyle(Paint.Style.STROKE);
}
/**
* 绘制多边形
*
* @param canvas
*/
private void drawPolygon(Canvas canvas) {
Path path = new Path();
//n边形数目
for (int j = 1; j <= num; j ) {
float r = j * this.r;
path.reset();
//画n边形
for (int i = 1; i <= n; i ) {
x = (float) (Math.cos(i * angle) * r);
y = (float) (Math.sin(i * angle) * r);
if (i == 1) {
path.moveTo(x, y);
} else {
path.lineTo(x, y);
}
}
//关闭当前轮廓。如果当前点不等于第一个点的轮廓,一条线段是自动添加的
path.close();
canvas.drawPath(path, borderPaint);
}
}
/**
* 画多边形线段
*
* @param canvas
*/
private void drawLine(Canvas canvas) {
Path path = new Path();
float r = num * this.r;
for (int i = 1; i <= n; i ) {
path.reset();
x = (float) (Math.cos(i * angle) * r);
y = (float) (Math.sin(i * angle) * r);
path.lineTo(x, y);
canvas.drawPath(path, borderPaint);
}
}
/**
* 画文字
*
* @param canvas
*/
private void drawText(Canvas canvas) {
float r = num * this.r;
for (int i = 1; i <= n; i ) {
//测量文字的宽高
Rect rect = new Rect();
textPaint.getTextBounds(text[i - 1], 0, text[i - 1].length(), rect);
float textWidth = rect.width();
float textHeight = rect.height();
x = (float) (Math.cos(i * angle) * r);
y = (float) (Math.sin(i * angle) * r);
//位置微调
if (x < 0) {
x = x - textWidth;
}
if (y > 25) {
y = y textHeight;
}
//调文字与边框的边距
float LastX = x x / num / textAlign;
float LastY = y y / num / textAlign;
canvas.drawText(text[i - 1],LastX, LastY, textPaint);
}
}
/**
* 画区域
*
* @param canvas
*/
private void drawArea(Canvas canvas) {
Path path = new Path();
for (int i= 1; i<= n; i ) {
float r = area[i - 1] * this.r;
x = (float) (Math.cos(i * angle) * r);
y = (float) (Math.sin(i * angle) * r);
if (i == 1) {
path.moveTo(x, y);
} else {
path.lineTo(x, y);
}
}
//关闭当前轮廓。如果当前点不等于第一个点的轮廓,一条线段是自动添加的
path.close();
canvas.drawPath(path, areaPaint);
}
public void setArea (int[] area){
this.area =area;
invalidate();
}
}2.界面布局文件xml中直接使用：
<com.lotus.chartspagedemo.MyPolygonView android:id="@ id/polygon" android:layout_width="match_parent" android:layout_height="match_parent" android:visibility="visible" />
3.界面activity中可以设置控件颜色：
polygon.setBackgroundColor(getResources().getColor(R.color.app_blue));//雷达图的背景颜色
如果不设置背景颜色，效果就是：
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持Devmax。