android 漏斗图

效果图

核心代码

1. 自定义View：FunnelChart

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.RectF;
import android.util.ArrayMap;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

import java.util.ArrayList;
import java.util.List;
import java.util.Map;

/**
 * Created by benz on 2020/12/22.
 */

public class FunnelChart extends View {

    private static final int SPACE = 3;
    private ArrayList<Path> mPaths = new ArrayList<>();
    private ArrayList<Paint> mPaints = new ArrayList<>();
    private List<FunnelData> mData;
    private OnValueTouchListener mTouchListener;

    public FunnelChart(Context context) {
        this(context, null);
    }

    public FunnelChart(Context context, AttributeSet attrs) {
        this(context, attrs, 0);
    }

    public FunnelChart(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

    public void setTouchListener(OnValueTouchListener touchListener) {
        mTouchListener = touchListener;
    }

    public void renderData(List<FunnelData> data) {
        if (data == null || data.isEmpty()) {
            return;
        }
        mData = data;
        mPaints.clear();
        for (int i = 0; i < mData.size(); i++) {
            Paint mPaint = new Paint();
            mPaint.setColor(mData.get(i).color);
            mPaint.setStyle(Paint.Style.FILL);
            mPaint.setDither(true);
            mPaint.setAntiAlias(true);
            mPaints.add(mPaint);
        }
        invalidate();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        if (mData == null || mData.isEmpty()) {
            Paint p = new Paint();
            p.setColor(Color.parseColor("#ffffff"));
            p.setStyle(Paint.Style.FILL);
            p.setDither(true);
            p.setAntiAlias(true);
            canvas.drawPaint(p);
            canvas.save();
            return;
        }
        mPaths.clear();
        float lastX = 0;
        float lastY = 0;
        float value1 = mData.get(0).value;
        for (int i = 0; i < mData.size(); i++) {
            Path mPath = new Path();
            mPath.moveTo(lastX, lastY);
            mPath.lineTo(lastX + mData.get(i).value * 1f / value1 * getWidth(), lastY);
            if (i < mData.size() - 1) {
                float value2 = mData.get(i + 1).value;
                mPath.lineTo(getWidth() / 2f + value2 / value1 * getWidth() / 2f, getHeight() * 1f / mData.size() * (i + 1) - SPACE);
                mPath.lineTo(getWidth() / 2f - value2 / value1 * getWidth() / 2f, getHeight() * 1f / mData.size() * (i + 1) - SPACE);
                lastX = getWidth() / 2f - value2 / value1 * getWidth() / 2f;
            } else {
                mPath.lineTo(getWidth() / 2f, getHeight() * 1f / mData.size() * (i + 1) - SPACE);
                mPath.lineTo(getWidth() / 2f, getHeight() * 1f / mData.size() * (i + 1) - SPACE);
                lastX = getWidth() / 2f;
            }
            mPath.close();
            mPaths.add(mPath);
            lastY = getHeight() * 1f / mData.size() * (i + 1) + SPACE;
            canvas.drawPath(mPaths.get(i), mPaints.get(i));
        }
        canvas.save();
    }

    @Override
    public boolean dispatchTouchEvent(MotionEvent event) {
        return super.dispatchTouchEvent(event);//默认实现，可以不写
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        if (mTouchListener != null) {
            float x = event.getX();
            float y = event.getY();
            for (int i = 0; i < mPaths.size(); i++) {
                Path path = mPaths.get(i);
                RectF rectF = new RectF();
                path.computeBounds(rectF, true);
                if (rectF.contains(x, y)) {
                    mTouchListener.onValueTouch(mData.get(i));
                    break;
                }
            }
            return true;
        } else {
            return super.onTouchEvent(event);
        }
    }

    public interface OnValueTouchListener{
        void onValueTouch(FunnelData funnelData);
    }

}

2. 自定义数据结构：FunnelData

/**
 * Created by benz on 2020/12/22.
 */

public class FunnelData {
    public float value;
    public int color;
}

如何使用

import android.graphics.Color;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

public class MainActivity extends AppCompatActivity {
    FunnelChart funnelView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        funnelView = (FunnelChart) findViewById(R.id.funnelview);
        funnelView.setTouchListener(new FunnelChart.OnValueTouchListener() {
            @Override
            public void onValueTouch(FunnelData funnelData) {
                Toast.makeText(MainActivity.this, "点击了" + funnelData.value, Toast.LENGTH_SHORT).show();
            }
        });
        List<FunnelData> data = new ArrayList<>();
        int size = 3;
        for (int i = 0; i < size; i++) {
            FunnelData funnelData = new FunnelData();
            funnelData.color = Color.parseColor(getRandColorCode());
            funnelData.value = getRandomNumber(1000 / (i + 1), 800 / (i + 1));
            data.add(funnelData);
        }
        funnelView.renderData(data);
    }

    private int getRandomNumber(int max, int min) {
        Random random = new Random();
        return random.nextInt(max) % (max - min + 1) + min;
    }

    private String getRandColorCode() {
        String r, g, b;
        Random random = new Random();
        r = Integer.toHexString(random.nextInt(256)).toUpperCase();
        g = Integer.toHexString(random.nextInt(256)).toUpperCase();
        b = Integer.toHexString(random.nextInt(256)).toUpperCase();
        r = r.length() == 1 ? "0" + r : r;
        g = g.length() == 1 ? "0" + g : g;
        b = b.length() == 1 ? "0" + b : b;
        return "#" + r + g + b;
    }
}

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#C0C1C2">

    <FunnelChart
        android:id="@+id/funnelview"
        android:layout_width="300dp"
        android:layout_height="200dp"
        android:layout_centerInParent="true"
        android:background="#ffffff" />
</RelativeLayout>