我正在尝试创建两个旋转轮，就像滑轮一样，所以每次连接的绳索移动时，两个滑轮都会旋转。我尝试了两种方法：
1）在 View 类的 onDraw() 方法中使用 Matrix.postRotate，该方法调用以下内容：
private void drawSpinningWheel(Canvas canvas)
{
try
{
canvas.save();
Bitmap bitmapOrg = null;
int iDrawable = R.drawable.spinning_button;
bitmapOrg = BitmapFactory.decodeResource(getResources(), iDrawable);
if(bitmapOrg != null)
{
int width = bitmapOrg.getWidth();
int height = bitmapOrg.getHeight();
int newWidth = 24;
int newHeight = 24;
// calculate the scale - in this case = 0.4f
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;
// createa matrix for the manipulation
Matrix matrix = new Matrix();
// resize the bit map
matrix.postScale(scaleWidth, scaleHeight);
matrix.postRotate((float) mDegrees++);
Bitmap resizedBitmap = Bitmap.createBitmap(bitmapOrg, 0, 0,
width, height, matrix, true);
canvas.drawBitmap(resizedBitmap, matrix, null);
}
canvas.restore();
}
catch(Exception e)
{
Log.e(TAG + "drawSpinningWheel", e.getMessage());
}
}
但看起来图像不仅旋转而且围绕另一个轴旋转
2）使用 SurfaceView 和一个单独的线程，在 run() 调用这个：
private void doDraw(Canvas canvas) {
// Draw the background image. Operations on the Canvas accumulate
// so this is like clearing the screen.
canvas.drawBitmap(mBackgroundImage, 0, 0, null);
int yTop = mCanvasHeight - ((int) mY + mSpinningWheelImageHeight / 2);
int xLeft = (int) mX - mSpinningWheelImageWidth / 2;
...
// Draw the ship with its current rotation
canvas.save();
canvas.rotate((float) mHeading++, (float) mX, mCanvasHeight
- (float) mY);
mSpinningWheelImage.setBounds(xLeft, yTop, xLeft + mSpinningWheelImageWidth, yTop
+ mSpinningWheelImageHeight);
mSpinningWheelImage.draw(canvas);
canvas.restore();
}
我让纺车工作，但我无法添加另一个纺车。我什至尝试为第二个纺车创建另一个线程，但只有一个出现。有人能指出我正确的方向吗？谢谢。
3）好的，现在我也尝试了RotateAnimation：
public class GraphicsView extends View { private static final String QUOTE = "没有人再使用 Java。这是一个重量级的大球和链子。";
private Animation anim;
private Animation anim2;
private Bitmap jobs;
private Bitmap wheel;
private int jobsXOffset;
private int jobsYOffset;
private int wheelXOffset;
private int wheelYOffset;
public GraphicsView(Context context)
{
super(context);
jobs = BitmapFactory
.decodeResource(getResources(), R.drawable.spinning_button);
jobsXOffset = jobs.getWidth() / 2;
jobsYOffset = jobs.getHeight() / 2;
wheel = BitmapFactory
.decodeResource(getResources(), R.drawable.wheel);
wheelXOffset = jobs.getWidth() / 2;
wheelYOffset = jobs.getHeight() / 2;
}
private void createAnim(Canvas canvas)
{
anim = new RotateAnimation(0, 360, canvas.getWidth() / 2, canvas
.getHeight() / 2);
anim.setRepeatMode(Animation.INFINITE);
anim.setRepeatCount(Animation.INFINITE);
anim.setDuration(10000L);
anim.setInterpolator(new AccelerateDecelerateInterpolator());
startAnimation(anim);
}
private void createAnim2(Canvas canvas)
{
anim2 = new RotateAnimation(0, 360, canvas.getWidth() / 2+30, canvas
.getHeight() / 2);
anim2.setRepeatMode(Animation.INFINITE);
anim2.setRepeatCount(Animation.INFINITE);
anim2.setDuration(10000L);
anim2.setInterpolator(new AccelerateDecelerateInterpolator());
startAnimation(anim);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
// creates the animation the first time
if (anim == null) {
createAnim(canvas);
}
int centerX = canvas.getWidth() / 2;
int centerY = canvas.getHeight() / 2;
canvas.drawBitmap(jobs, centerX - jobsXOffset,
centerY - jobsYOffset, null);
canvas.drawBitmap(wheel, centerX - wheelXOffset + 30,
centerY - wheelYOffset, null);
}
}
但结果类似于 Canvas.Rotate，我能够让第一张图像旋转得很好，但第二张图像只会围绕第一张图像旋转，尽管我注意到第二张图像实际上也在旋转。看起来我需要一个单独的视图来查看第二张图片，我希望避免这种情况，因为我不确定如何让轮子旋转，但连接的绳索不会旋转。