如何在Android中创建使用情况饼图？请提供实现帮助

方案一：使用MPAndroidChart第三方库 #

这是Android开发中常用的图表库，可快速实现带百分比标注的饼图。

1. 添加依赖 #

在Module级别的build.gradle文件中添加依赖：

dependencies {
    implementation 'com.github.PhilJay:MPAndroidChart:v3.1.0'
}

2. 布局中添加PieChart #

<com.github.mikephil.charting.charts.PieChart
    android:id="@+id/pieChart"
    android:layout_width="match_parent"
    android:layout_height="300dp"/>

3. 代码中配置数据与样式 #

PieChart pieChart = findViewById(R.id.pieChart);

// 准备饼图数据
ArrayList<PieEntry> entries = new ArrayList<>();
entries.add(new PieEntry(30f, "类别A"));
entries.add(new PieEntry(20f, "类别B"));
entries.add(new PieEntry(50f, "类别C"));

// 配置数据集
PieDataSet dataSet = new PieDataSet(entries, "数据占比");
// 设置各区块颜色
dataSet.setColors(Color.parseColor("#FF6B6B"), Color.parseColor("#4ECDC4"), Color.parseColor("#45B7D1"));
// 开启数值显示并设置为百分比格式
dataSet.setDrawValues(true);
dataSet.setValueFormatter(new PercentFormatter(pieChart));
dataSet.setValueTextSize(12f);
dataSet.setValueTextColor(Color.WHITE);

// 组装饼图数据
PieData pieData = new PieData(dataSet);
pieChart.setData(pieData);

// 调整样式
pieChart.getDescription().setEnabled(false); // 隐藏默认描述
pieChart.setDrawHoleEnabled(false); // 不绘制中心空心区域
pieChart.setRotationEnabled(false); // 禁止手动旋转
pieChart.invalidate(); // 刷新图表

方案二：自定义View实现 #

如果需要高度定制饼图样式，可通过自定义View实现：

1. 创建自定义PieChartView类 #

public class PieChartView extends View {
    private Paint mPaint;
    private List<Float> mDataList;
    private List<Integer> mColorList;
    private RectF mChartRect;
    private float mTotalValue;

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

    public PieChartView(Context context, AttributeSet attrs) {
        super(context, attrs);
        init();
    }

    private void init() {
        mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        mChartRect = new RectF();
    }

    // 设置饼图数据、颜色
    public void setChartData(List<Float> dataList, List<Integer> colorList) {
        this.mDataList = dataList;
        this.mColorList = colorList;
        // 计算数据总和
        mTotalValue = 0;
        for (float value : dataList) {
            mTotalValue += value;
        }
        invalidate();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        if (mDataList == null || mDataList.isEmpty()) return;

        int centerX = getWidth() / 2;
        int centerY = getHeight() / 2;
        int radius = Math.min(centerX, centerY) - 50;

        // 定义饼图绘制区域
        mChartRect.set(centerX - radius, centerY - radius, centerX + radius, centerY + radius);

        float startAngle = 0f;
        for (int i = 0; i < mDataList.size(); i++) {
            float sweepAngle = (mDataList.get(i) / mTotalValue) * 360;
            // 绘制饼图区块
            mPaint.setColor(mColorList.get(i));
            canvas.drawArc(mChartRect, startAngle, sweepAngle, true, mPaint);

            // 绘制百分比文字
            float textAngle = startAngle + sweepAngle / 2;
            float textX = centerX + (radius / 2) * (float) Math.cos(Math.toRadians(textAngle));
            float textY = centerY + (radius / 2) * (float) Math.sin(Math.toRadians(textAngle));

            mPaint.setColor(Color.WHITE);
            mPaint.setTextSize(16f);
            mPaint.setTextAlign(Paint.Align.CENTER);
            String percentText = String.format("%.1f%%", (mDataList.get(i)/mTotalValue)*100);
            canvas.drawText(percentText, textX, textY, mPaint);

            startAngle += sweepAngle;
        }
    }
}

2. 布局中使用自定义View #

<com.yourpackage.PieChartView
    android:id="@+id/customPieChart"
    android:layout_width="match_parent"
    android:layout_height="300dp"/>

3. 代码中设置数据 #

PieChartView customPieChart = findViewById(R.id.customPieChart);

List<Float> data = Arrays.asList(30f, 20f, 50f);
List<Integer> colors = Arrays.asList(Color.parseColor("#FF6B6B"), Color.parseColor("#4ECDC4"), Color.parseColor("#45B7D1"));
customPieChart.setChartData(data, colors);

内容的提问来源于stack exchange，提问作者Krishna Pandey