Android自定义View之网络图

新建项目，新建CircualRectView类继承自View，实现OnGlobalLayoutListener接口，
定义变量（RectModel为实体类）：

private Context mContext;    private int mViewWidth,mViewHeight;    private Paint mRectPaint,mTextPaint,mLinePaint;    private List<String> mDrawingText;    private List<RectModel> mRectModels;    private int mCenterRectHeight = 50;    private int mChildRectDistance = 200 ;    private int mSingleChildDegreeDistance;

添加绘制代码，修改onDraw函数如下：

public void init(Context context){        mContext = context;        mRectPaint = new Paint(Paint.ANTI_ALIAS_FLAG);        mTextPaint = new Paint();        mLinePaint = new Paint(Paint.ANTI_ALIAS_FLAG);        mRectPaint.setStyle(Paint.Style.FILL);        mRectPaint.setColor(Color.BLUE);        mTextPaint.setStrokeWidth(3);        mTextPaint.setColor(Color.RED);        mLinePaint.setColor(Color.BLUE);        mRectModels = new ArrayList<>();        mDrawingText = new ArrayList<>();        mDrawingText.add("中心节点");        mDrawingText.add("节点1");        mDrawingText.add("节点2");        mDrawingText.add("节点3");        mDrawingText.add("节点4");        mDrawingText.add("节点5");        mDrawingText.add("节点6");        mDrawingText.add("节点7");        getViewTreeObserver().addOnGlobalLayoutListener(this);    }    @Override    public void onGlobalLayout() {        mViewWidth = getWidth();        mViewHeight = getHeight();    }    @Override    protected void onDraw(Canvas canvas) {        /*        * 绘制中心节点        * */        RectModel rectModel = new RectModel(MeasureUtils.getRect(mViewWidth/2,mViewHeight/2,mDrawingText.get(0).length()*20,mCenterRectHeight),mDrawingText.get(0),0);        mRectModels.add(rectModel);        drawNode(canvas,rectModel);        /*        * 画周围子节点        * */        mSingleChildDegreeDistance = 360 / (mDrawingText.size()-1);        for (int i=0;i<mDrawingText.size()-1;i++){            RectModel rectModel1 = new RectModel(MeasureUtils.getRect(mChildRectDistance+mViewWidth/2,mViewHeight/2,mDrawingText.get(i+1).length()*20,mCenterRectHeight),mDrawingText.get(i+1),i*mSingleChildDegreeDistance);            mRectModels.add(rectModel1);            drawNode(canvas,rectModel1);            canvas.drawLine(mViewWidth/2,mViewHeight/2,rectModel1.getCenterX(),mViewHeight/2,mLinePaint);            canvas.rotate(mSingleChildDegreeDistance,mViewWidth/2,mViewHeight/2);        }        super.onDraw(canvas);    }    public void drawNode(Canvas canvas,RectModel rectModel){        /*        * 锁定画布，将画布旋转回原始坐标系        * */        canvas.save();        canvas.rotate(-rectModel.getAngle(),rectModel.getCenterX(),rectModel.getCenterY());        canvas.drawRect(rectModel.getLeft(),rectModel.getTop(),rectModel.getRight(),rectModel.getBottom(),mRectPaint);        Paint.FontMetricsInt fontMetrics = mRectPaint.getFontMetricsInt();        int baseline = (rectModel.getBottom() + rectModel.getTop() - fontMetrics.bottom - fontMetrics.top) / 2;        mTextPaint.setTextAlign(Paint.Align.CENTER);        canvas.drawText(rectModel.getText(), rectModel.getCenterX(), baseline, mTextPaint);        /*        * 释放画布        * */        canvas.restore();    }

运行效果如下：