Hello Android 之 Graphics 实例

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原创最新推荐文章于 2026-10-30 19:18:21 发布 446 阅读 AI 写同款· GEO 优化 ›

XZ8922：5V USB升压充双节锂电的工程解法双节串联锂电（标称7.4V/满电8.4V）在便携设备中广泛应用，但受限于5V USB供电源，传统降压型充电IC无法实现有效充电——本质是输入电压低于电池平台电压导致的能量路径断层。XZ8922通过单电感Boost-Buck-Boost架构，在ESOP8封装内集成自适应升压引擎与USB PD协议解析，突破‘5V充8.4V’物理约束，兼顾高效率（89.3%）、低温可靠启动（-10℃）与微功耗待机（42μA）。其技术价值在于将升压、充电、系统供电与热管理深度耦合，适用于手持仪表、热成像仪、POS机等空间敏感、温域阅读详情

在Activity中使用自定义View，在View的onDraw方法中手工绘图。

public class Graphics extends Activity { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(new GraphicsView(this)); } static public class GraphicsView extends View { private static final String QUOTE = "Now is the time for all " + "good men to come to the aid of their country."; private final Path circle; private final Paint cPaint; private final Paint tPaint; public GraphicsView(Context context) { super(context); // Color examples int color = Color.BLUE; // solid blue // Translucent purple color = Color.argb(127, 255, 0, 255); color = getResources().getColor(R.color.mycolor); circle = new Path(); circle.addCircle(150, 150, 100, Direction.CW); cPaint = new Paint(Paint.ANTI_ALIAS_FLAG); cPaint.setStyle(Paint.Style.STROKE); cPaint.setColor(Color.LTGRAY); cPaint.setStrokeWidth(3); tPaint = new Paint(Paint.ANTI_ALIAS_FLAG); tPaint.setStyle(Paint.Style.FILL_AND_STROKE); tPaint.setColor(Color.BLACK); tPaint.setTextSize(20f); // setBackgroundColor(Color.WHITE); setBackgroundResource(R.drawable.background); } @Override protected void onDraw(Canvas canvas) { // Drawing commands go here canvas.drawPath(circle, cPaint); canvas.drawTextOnPath(QUOTE, circle, 0, 20, tPaint); } } }

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