我想要像 Android 上的 Facebook 个人资料图像选择一样裁剪图像,用户可以在其中移动和缩放图像,从而调整图像大小和/或裁剪图像:
我怎样才能做到这一点?
最佳答案
我有同样的要求。我结合 PhotoView 解决了它和 Cropper通过在 cropper 库中将 ImageView
替换为 PhotoView
。
我不得不修改 CropWindow
类以避免触摸事件没有被正确处理:
public void setImageView(PhotoView pv){
mPhotoView = pv;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
// If this View is not enabled, don't allow for touch interactions.
if (!isEnabled()) {
return false;
}
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
boolean dispatch = onActionDown(event.getX(), event.getY());
if(!dispatch)
mPhotoView.dispatchTouchEvent(event);
return dispatch;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
getParent().requestDisallowInterceptTouchEvent(false);
onActionUp();
return true;
case MotionEvent.ACTION_MOVE:
onActionMove(event.getX(), event.getY());
getParent().requestDisallowInterceptTouchEvent(true);
return true;
default:
return false;
}
}
在 CropImageView
类中也做了一些改变:
private void init(Context context) {
final LayoutInflater inflater = LayoutInflater.from(context);
final View v = inflater.inflate(R.layout.crop_image_view, this, true);
mImageView = (PhotoView) v.findViewById(R.id.ImageView_image2);
setImageResource(mImageResource);
mCropOverlayView = (CropOverlayView) v.findViewById(R.id.CropOverlayView);
mCropOverlayView.setInitialAttributeValues(mGuidelines, mFixAspectRatio, mAspectRatioX, mAspectRatioY);
mCropOverlayView.setImageView(mImageView);
}
您会注意到我已经将 Cropper 库中 R.layout.crop_image_view
中的 ImageView
替换为 PhotoView
。
Cropper 库支持固定尺寸,而 PhotoView 允许您移动和缩放照片,让您两全其美。 :)
希望对您有所帮助。
编辑,对于那些询问如何获取仅在裁剪区域内的图像的人:
private Bitmap getCurrentDisplayedImage(){
Bitmap result = Bitmap.createBitmap(mImageView.getWidth(), mImageView.getHeight(), Bitmap.Config.RGB_565);
Canvas c = new Canvas(result);
mImageView.draw(c);
return result;
}
public Bitmap getCroppedImage() {
Bitmap mCurrentDisplayedBitmap = getCurrentDisplayedImage();
final Rect displayedImageRect = ImageViewUtil2.getBitmapRectCenterInside(mCurrentDisplayedBitmap, mImageView);
// Get the scale factor between the actual Bitmap dimensions and the
// displayed dimensions for width.
final float actualImageWidth =mCurrentDisplayedBitmap.getWidth();
final float displayedImageWidth = displayedImageRect.width();
final float scaleFactorWidth = actualImageWidth / displayedImageWidth;
// Get the scale factor between the actual Bitmap dimensions and the
// displayed dimensions for height.
final float actualImageHeight = mCurrentDisplayedBitmap.getHeight();
final float displayedImageHeight = displayedImageRect.height();
final float scaleFactorHeight = actualImageHeight / displayedImageHeight;
// Get crop window position relative to the displayed image.
final float cropWindowX = Edge.LEFT.getCoordinate() - displayedImageRect.left;
final float cropWindowY = Edge.TOP.getCoordinate() - displayedImageRect.top;
final float cropWindowWidth = Edge.getWidth();
final float cropWindowHeight = Edge.getHeight();
// Scale the crop window position to the actual size of the Bitmap.
final float actualCropX = cropWindowX * scaleFactorWidth;
final float actualCropY = cropWindowY * scaleFactorHeight;
final float actualCropWidth = cropWindowWidth * scaleFactorWidth;
final float actualCropHeight = cropWindowHeight * scaleFactorHeight;
// Crop the subset from the original Bitmap.
final Bitmap croppedBitmap = Bitmap.createBitmap(mCurrentDisplayedBitmap,
(int) actualCropX,
(int) actualCropY,
(int) actualCropWidth,
(int) actualCropHeight);
return croppedBitmap;
}
public RectF getActualCropRect() {
final Rect displayedImageRect = ImageViewUtil.getBitmapRectCenterInside(mBitmap, mImageView);
final float actualImageWidth = mBitmap.getWidth();
final float displayedImageWidth = displayedImageRect.width();
final float scaleFactorWidth = actualImageWidth / displayedImageWidth;
// Get the scale factor between the actual Bitmap dimensions and the displayed
// dimensions for height.
final float actualImageHeight = mBitmap.getHeight();
final float displayedImageHeight = displayedImageRect.height();
final float scaleFactorHeight = actualImageHeight / displayedImageHeight;
// Get crop window position relative to the displayed image.
final float displayedCropLeft = Edge.LEFT.getCoordinate() - displayedImageRect.left;
final float displayedCropTop = Edge.TOP.getCoordinate() - displayedImageRect.top;
final float displayedCropWidth = Edge.getWidth();
final float displayedCropHeight = Edge.getHeight();
// Scale the crop window position to the actual size of the Bitmap.
float actualCropLeft = displayedCropLeft * scaleFactorWidth;
float actualCropTop = displayedCropTop * scaleFactorHeight;
float actualCropRight = actualCropLeft + displayedCropWidth * scaleFactorWidth;
float actualCropBottom = actualCropTop + displayedCropHeight * scaleFactorHeight;
// Correct for floating point errors. Crop rect boundaries should not exceed the
// source Bitmap bounds.
actualCropLeft = Math.max(0f, actualCropLeft);
actualCropTop = Math.max(0f, actualCropTop);
actualCropRight = Math.min(mBitmap.getWidth(), actualCropRight);
actualCropBottom = Math.min(mBitmap.getHeight(), actualCropBottom);
final RectF actualCropRect = new RectF(actualCropLeft,
actualCropTop,
actualCropRight,
actualCropBottom);
return actualCropRect;
}
private boolean onActionDown(float x, float y) {
final float left = Edge.LEFT.getCoordinate();
final float top = Edge.TOP.getCoordinate();
final float right = Edge.RIGHT.getCoordinate();
final float bottom = Edge.BOTTOM.getCoordinate();
mPressedHandle = HandleUtil.getPressedHandle(x, y, left, top, right, bottom, mHandleRadius);
if (mPressedHandle == null)
return false;
mTouchOffset = HandleUtil2.getOffset(mPressedHandle, x, y, left, top, right, bottom);
invalidate();
return true;
}
关于android - 如何像 Facebook 个人资料图片选择工具那样移动和缩放图片?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/22683887/