Android Canvas类介绍
import android.content.Context; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Paint; import android.graphics.Rect; import android.view.KeyEvent; import android.view.MotionEvent; import android.view.View; public class GameView extends View implements Runnable { /* 声明Paint对象 */ private Paint mPaint = null; public GameView(Context context) { super(context); /* 构建对象 */ mPaint = new Paint(); /* 开启线程 */ new Thread(this).start(); } public void onDraw(Canvas canvas) { super.onDraw(canvas); /* 设置画布的颜色 */ canvas.drawColor(Color.BLACK); /* 设置取消锯齿效果 */ mPaint.setAntiAlias(true); /* 设置裁剪区域 */ canvas.clipRect(10, 10, 280, 260); /* 线锁定画布 */ canvas.save(); /* 旋转画布 */ canvas.rotate(45.0f); /* 设置颜色及绘制矩形 */ mPaint.setColor(Color.RED); canvas.drawRect(new Rect(15, 15, 140, 70), mPaint); /* 解除画布的锁定 */ canvas.restore(); /* 设置颜色及绘制另一个矩形 */ mPaint.setColor(Color.GREEN); canvas.drawRect(new Rect(150, 75, 260, 120), mPaint); } // 触笔事件 public boolean onTouchEvent(MotionEvent event) { return true; } // 按键按下事件 public boolean onKeyDown(int keyCode, KeyEvent event) { return true; } // 按键弹起事件 public boolean onKeyUp(int keyCode, KeyEvent event) { return false; } public boolean onKeyMultiple(int keyCode, int repeatCount, KeyEvent event) { return true; } public void run() { while (!Thread.currentThread().isInterrupted()) { try { Thread.sleep(100); } catch (InterruptedException e) { Thread.currentThread().interrupt(); } // 使用postInvalidate可以直接在线程中更新界面 postInvalidate(); } } }
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