如何创建自定义Android视图？ 使用XML对象还是绘图API？

Question

I'm trying to create a new view that would:

• load an image

• allow the user to zoom and rotate the image with two fingers while a "cropping box" stays translucent over the top while the image extends beyond the "cropping box"

• with the end goal of being able to mark the rotation and position of the main image (so that later i could crop out or show the area within the cropping box)

I'm wondering if I can do this with an ImageView holding the image in the background and another ImageView holding the crop box on top of it, then using TouchEvents to move the image, would this work?

Or do I need to use some drawing API on a 2D surface?

I'm just really new to creating custom objects in Android that aren't just customized out-of-the-box Views.

What's the standard way of creating something like this?

Thanks!

Answer 1

Create a Compound View by extending RelativeLayout with two overlapping ImageView s in it. Then override onTouch event or override onGestureDetector interface in that newly created View.

Official Documentation: http://developer.android.com/guide/topics/ui/custom-components.html Another Tutorial: http://www.vogella.com/tutorials/AndroidCustomViews/article.html