问题
I want to apply drag,zoom in/out,rotate using multitouch to two images .one image is placed on the top of the other. after applying these action
Create a image
from above two images after changes made by applying actions.
I succeed in apply zoom/drag to top image ,created new image from that.
main problem is
1.How to apply action to two images, one image at a time ?
2.How to switch to another image from currently showing image (which layout I should use)?
3.How user can have a facility to rotate or zoom a image using multitouch ?
What I am missing, Sorry for the list -:)
回答1:
1) You need to keep the transformation done to Bitmap1 and apply it again to Bitmap2. for example you can use a Matrix calculated using touch events in order to apply it to the two Bitmaps.
2) I am not sure to uderstand what you want to do. What i understand is: you've got multiple imageview (that can be composed of 2 images placed on top of another) floating on the layout and you want to select one of them to resize / rotate it. In order to do that you can simply use the ontouch event of an imageView.
3) Rotate + zoom with multitouch is not easy in Android, lots of code have to be written in order to make it work nicely. I suggest you to use an existing library. I used this one and it worked like a charm: http://code.google.com/p/android-multitouch-controller/
You can see in the sample provided http://code.google.com/p/android-multitouch-controller/source/browse/trunk/demo/MTPhotoSortr/src/org/metalev/multitouch/photosortr/PhotoSortrView.java that you can retreive at any time the new center, angle, and scale ratio of the updated images in mImages(i).getCenterX(), mImages(i).getAngle(), mImages(i).getScaleX(), ...
Using this values you can replicate the transformations (rotation, scaling, translation) on another Bitmap.
来源：https://stackoverflow.com/questions/5256421/how-to-perform-zoom-in-out-rotation-together-in-android