自定义View,教你画个饼状图

观看大大博客照着写了个demo，注释都在代码里话不多说，上代码

public class MyAnalysisChart extends View {
    private Paint mPaint = new Paint();
    //颜色数组
    private int[] mColors = {0xFFCCFF00, 0xFF6495ED, 0xFFE32636, 0xFF800000, 0xFF808000, 0xFFFF8C69, 0xFF808080,
            0xFFE6B800, 0xFF7CFC00};
    //饼状图绘制初始角度
    private float mStartAngle = 0;
    //数据集合
    List mData;

    //宽高
    private int mWidth, mHight;

    public MyAnalysisChart(Context context) {
        super(context, null);
    }

    public MyAnalysisChart(Context context, AttributeSet attrs) {
        super(context, attrs);
        mPaint.setStyle(Paint.Style.FILL);
        mPaint.setAntiAlias(true);  //是否抗锯齿
    }

    //首先测量宽高
    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh) {
        super.onSizeChanged(w, h, oldw, oldh);
        mWidth = w;
        mHight = h;
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        if (null == mData)
            return;
        float currentStartAngle = mStartAngle;                    // 当前起始角度
        canvas.translate(mWidth / 2, mHight / 2);                // 将画布坐标原点移动到中心位置
        float r = (float) (Math.min(mWidth, mHight) / 2 * 0.8);  // 饼状图半径
        RectF rect = new RectF(-r, -r, r, r);                     // 饼状图绘制区域

        for (int i = 0; i < mData.size(); i++) {
            PieData pie = mData.get(i);
            mPaint.setColor(pie.getColor());
            canvas.drawArc(rect, currentStartAngle, pie.getAngle(), true, mPaint);
            currentStartAngle += pie.getAngle();
        }
    }



    //设置起始角度
    public void setCurrenStartAngle(int mStartAngle) {
        this.mStartAngle = mStartAngle;
        invalidate();//刷新
    }

    //设置数据
    public void setData(ArrayList mData) {
        this.mData= mData;
        initData(mData); //初始化数据
        invalidate();//刷新
    }

    private void initData(ArrayList mData) {
        if (null == mData || mData.size() == 0) {
            return;
        }
        float sumValue = 0;

        for (int i = 0; i 

MainActivty插入伪数据

public class MainActivity extends AppCompatActivity {
    private ArrayList mlist = new ArrayList();

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        MyAnalysisChart myAnalysisChart = (MyAnalysisChart) findViewById(R.id.myasc);
        PieData pieData = new PieData("你好",10);
        PieData pieData1 = new PieData("你好1",20);
        PieData pieData2 = new PieData("你好2",30);
        PieData pieData3= new PieData("你好3",40);

        mlist.add(pieData);
        mlist.add(pieData1);
        mlist.add(pieData2);
        mlist.add(pieData3);

        myAnalysisChart.setData( mlist);


    }

xml布局调用自定义控件

OK，下面贴上运行效果

Paste_Image.png