我的代码：
public class MainActivity extends GraphicsActivity{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(new MyView(this));
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(0xffffffff);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setStrokeWidth(12);
mEmboss = new EmbossMaskFilter(new float[] { 1, 1, 1 },
0.4f, 6, 3.5f);
mPaint.setMaskFilter(mEmboss);
//mBlur = new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL);
}
private Paint mPaint;
private MaskFilter mEmboss;
public class MyView extends View {
private Bitmap mBitmap;
private Canvas mCanvas;
private Path mPath;
private Paint mBitmapPaint;
public MyView(Context c) {
super(c);
Bitmap bmp = BitmapFactory.decodeResource(getResources(), R.drawable.t01);
Display display = getWindowManager().getDefaultDisplay();
int height = display.getWidth();
int width = display.getHeight();
mBitmap = Bitmap.createScaledBitmap(bmp, height, width, true);
//mBitmap = Bitmap.createBitmap(320, 480, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
mPath = new Path();
mBitmapPaint = new Paint(Paint.DITHER_FLAG);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.drawPath(mPath, mPaint);
}
private float mX, mY;
private static final float TOUCH_TOLERANCE = 4;
private void touch_start(float x, float y) {
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touch_move(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX)/2, (y + mY)/2);
mX = x;
mY = y;
}
}
private void touch_up() {
mPath.lineTo(mX, mY);
// commit the path to our offscreen
mCanvas.drawPath(mPath, mPaint);
// kill this so we don't double draw
mPath.reset();
}
@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touch_start(x, y);
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touch_move(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touch_up();
invalidate();
break;
}
return true;
}
}
}
我的xml：
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ImageView
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:src="@drawable/t01"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true" />
</RelativeLayout>
现在我想将活动中的视图添加到这个 xml 中，并且我想把这个视图放在布局上，以便必须看到图像和视图。实际上，我正在尝试在图像中的字母线条内绘制。比如追踪这封信。而且我不希望我的画布绘制在图像中排除我的信的轮廓。如果它越过，那么我想发出一些警告声音。
请帮助我如何做到这一点？提前致谢。