android - 如何在 fragment 中设置内容 View ？

Question

现在我有了这个 fragment ，我想将它与 setContentView 一起使用，但到目前为止我找不到方法。您可以在下面的代码中看到我的案例，我没有尝试扩展布局，而是尝试将其与名为 SampleView 的 View 一起使用。那么我该怎么做呢？提前致谢

public class largeImageScroller extends SherlockFragment {

// Physical display width and height.
private static int displayWidth = 0;
private static int displayHeight = 0;

/** Called when the activity is first created. */
public View onCreateView(LayoutInflater inflater, ViewGroup group, Bundle saved) {

        getActivity();
        // displayWidth and displayHeight will change depending on screen
        // orientation. To get these dynamically, we should hook onSizeChanged().
        // This simple example uses only landscape mode, so it's ok to get them
        // once on startup and use those values throughout.

        Display display = ((WindowManager)
getActivity().getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
        displayWidth = display.getWidth();             
        displayHeight = display.getHeight();    

        // SampleView constructor must be constructed last as it needs the
        // displayWidth and displayHeight we just got.
        setContentView(new SampleView(this));
}

private static class SampleView extends View {
        private static Bitmap bmLargeImage; //bitmap large enough to be scrolled
        private static Rect displayRect = null; //rect we display to
        private Rect scrollRect = null; //rect we scroll over our bitmap with
        private int scrollRectX = 0; //current left location of scroll rect
        private int scrollRectY = 0; //current top location of scroll rect
        private float scrollByX = 0; //x amount to scroll by
        private float scrollByY = 0; //y amount to scroll by
        private float startX = 0; //track x from one ACTION_MOVE to the next
        private float startY = 0; //track y from one ACTION_MOVE to the next

        public SampleView(Context context) {
                super(context);

                // Destination rect for our main canvas draw. It never changes.
                displayRect = new Rect(0, 0, displayWidth, displayHeight);
                // Scroll rect: this will be used to 'scroll around' over the
                // bitmap in memory. Initialize as above.
                scrollRect = new Rect(0, 0, displayWidth, displayHeight);

                // Load a large bitmap into an offscreen area of memory.
                bmLargeImage = BitmapFactory.decodeResource(getResources(),
                        R.drawable.ground_floor_b);
        }

        @Override
        public boolean onTouchEvent(MotionEvent event) {

                switch (event.getAction()) {
                        case MotionEvent.ACTION_DOWN:
                                // Remember our initial down event location.
                                startX = event.getRawX();
                                startY = event.getRawY();
                                break;

                        case MotionEvent.ACTION_MOVE:
                                float x = event.getRawX();
                                float y = event.getRawY();
                                // Calculate move update. This will happen many times
                                // during the course of a single movement gesture.
                                scrollByX = x - startX; //move update x increment
                                scrollByY = y - startY; //move update y increment
                                startX = x; //reset initial values to latest
                                startY = y;
                                invalidate(); //force a redraw
                                break;
                }
                return true; //done with this event so consume it
        }

        @Override
        protected void onDraw(Canvas canvas) {

                // Our move updates are calculated in ACTION_MOVE in the opposite direction
                // from how we want to move the scroll rect. Think of this as dragging to
                // the left being the same as sliding the scroll rect to the right.
                int newScrollRectX = scrollRectX - (int)scrollByX;
                int newScrollRectY = scrollRectY - (int)scrollByY;

                // Don't scroll off the left or right edges of the bitmap.
                if (newScrollRectX < 0)
                        newScrollRectX = 0;
                else if (newScrollRectX > (bmLargeImage.getWidth() - displayWidth))
                        newScrollRectX = (bmLargeImage.getWidth() - displayWidth);

                // Don't scroll off the top or bottom edges of the bitmap.
                if (newScrollRectY < 0)
                        newScrollRectY = 0;
                else if (newScrollRectY > (bmLargeImage.getHeight() - displayHeight))
                        newScrollRectY = (bmLargeImage.getHeight() - displayHeight);

                // We have our updated scroll rect coordinates, set them and draw.
                scrollRect.set(newScrollRectX, newScrollRectY,
                        newScrollRectX + displayWidth, newScrollRectY + displayHeight);
                Paint paint = new Paint();
                canvas.drawBitmap(bmLargeImage, scrollRect, displayRect, paint);

                // Reset current scroll coordinates to reflect the latest updates,
                // so we can repeat this update process.
                scrollRectX = newScrollRectX;
                scrollRectY = newScrollRectY;
        }
}
}

Answer 1

你不要在 fragment 中调用setContentView，实际上你需要从onCreateView返回一个View。

尝试替换:

setContentView(new SampleView(this));

有了这个:

return new SampleView(this);