package com.example.hellojnicallback;
import android.content.Context;import android.graphics.Canvas;import android.graphics.Color;import android.graphics.Paint;import android.graphics.RectF;import android.util.AttributeSet;import android.view.View;
import androidx.annotation.Nullable;
public class PieChart extends View { Paint paint = new Paint(Paint.ANTI_ALIAS_FLAG); private static final float RADIUS = Util.dp2px(150); private static final float LENGTH = Util.dp2px(25); private static final float PULLED_OUT_INDEX = 0; RectF bounds = new RectF();
private static final int[] angles = {60, 100, 120, 80}; private static final int[] colors = {Color.RED, Color.BLUE, Color.GREEN, Color.YELLOW};
@Override protected void onSizeChanged(int w, int h, int oldw, int oldh) { super.onSizeChanged(w, h, oldw, oldh);
paint.setColor(Color.RED); bounds.set(getWidth()/2-RADIUS, getHeight()/2-RADIUS, getWidth()/2+RADIUS, getHeight()/2+RADIUS); }
@Override protected void onDraw(Canvas canvas) { super.onDraw(canvas);
int currentAngel = 0; for (int i = 0; i < angles.length; i++) { paint.setColor(colors[i]); canvas.save(); // 记录绘制前的位置信息 if (i == PULLED_OUT_INDEX) { float dx = (float) (LENGTH * Math.cos(Math.toRadians(currentAngel+angles[i]/2.0f))); float dy = (float) (LENGTH * Math.sin(Math.toRadians(currentAngel+angles[i]/2.0f))); canvas.translate(dx, dy); } canvas.drawArc(bounds, currentAngel, angles[i], true, paint); canvas.restore(); // 恢复绘制前的信息 currentAngel += angles[i]; } }
public PieChart(Context context, @Nullable AttributeSet attrs) { super(context, attrs); }}
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