如何滚动放大图片?

时间:2016-06-30 06:26:06

标签: android image

我有一个垂直方向线性布局,里面有横向画面。

问题是图片在垂直方向上看起来很小,所以我使用dev.android中的缩放方法。

现在图像以原始尺寸显示,但它比手机屏幕大。因此,用户只能看到部分图像。如何让用户在放大时左右滚动图片?

@Override
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_insane1x1);
    ActionBar actionBar = getSupportActionBar();
    actionBar.hide(); 

    final View thumb1View = findViewById(R.id.imageView1);
    thumb1View.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            zoomImageFromThumb(thumb1View, R.drawable.i1x1);
        }
    });

    // Retrieve and cache the system's default "short" animation time.
    mShortAnimationDuration = getResources().getInteger(
            android.R.integer.config_shortAnimTime);

}


private void zoomImageFromThumb(final View thumbView, int imageResId) {
    // If there's an animation in progress, cancel it immediately and proceed with this one.
    if (mCurrentAnimator != null) {
        mCurrentAnimator.cancel();
    }

    // Load the high-resolution "zoomed-in" image.
    final ImageView expandedImageView = (ImageView) findViewById(R.id.expanded_image);
    expandedImageView.setImageResource(imageResId);

    // Calculate the starting and ending bounds for the zoomed-in image. This step
    // involves lots of math. Yay, math.
    final Rect startBounds = new Rect();
    final Rect finalBounds = new Rect();
    final Point globalOffset = new Point();

    // The start bounds are the global visible rectangle of the thumbnail, and the
    // final bounds are the global visible rectangle of the container view. Also
    // set the container view's offset as the origin for the bounds, since that's
    // the origin for the positioning animation properties (X, Y).
    thumbView.getGlobalVisibleRect(startBounds);
    findViewById(R.id.container).getGlobalVisibleRect(finalBounds, globalOffset);
    startBounds.offset(-globalOffset.x, -globalOffset.y);
    finalBounds.offset(-globalOffset.x, -globalOffset.y);

    // Adjust the start bounds to be the same aspect ratio as the final bounds using the
    // "center crop" technique. This prevents undesirable stretching during the animation.
    // Also calculate the start scaling factor (the end scaling factor is always 1.0).
    float startScale;
    if ((float) finalBounds.width() / finalBounds.height()
            > (float) startBounds.width() / startBounds.height()) {
        // Extend start bounds horizontally
        startScale = (float) startBounds.height() / finalBounds.height();
        float startWidth = startScale * finalBounds.width();
        float deltaWidth = (startWidth - startBounds.width()) / 2;
        startBounds.left -= deltaWidth;
        startBounds.right += deltaWidth;
    } else {
        // Extend start bounds vertically
        startScale = (float) startBounds.width() / finalBounds.width();
        float startHeight = startScale * finalBounds.height();
        float deltaHeight = (startHeight - startBounds.height()) / 2;
        startBounds.top -= deltaHeight;
        startBounds.bottom += deltaHeight;
    }

    // Hide the thumbnail and show the zoomed-in view. When the animation begins,
    // it will position the zoomed-in view in the place of the thumbnail.
    thumbView.setAlpha(0f);
    expandedImageView.setVisibility(View.VISIBLE);

    // Set the pivot point for SCALE_X and SCALE_Y transformations to the top-left corner of
    // the zoomed-in view (the default is the center of the view).
    expandedImageView.setPivotX(0f);
    expandedImageView.setPivotY(0f);

    // Construct and run the parallel animation of the four translation and scale properties
    // (X, Y, SCALE_X, and SCALE_Y).
    AnimatorSet set = new AnimatorSet();
    set
            .play(ObjectAnimator.ofFloat(expandedImageView, View.X, startBounds.left,
                    finalBounds.left))
            .with(ObjectAnimator.ofFloat(expandedImageView, View.Y, startBounds.top,
                    finalBounds.top))
            .with(ObjectAnimator.ofFloat(expandedImageView, View.SCALE_X, startScale, 1f))
            .with(ObjectAnimator.ofFloat(expandedImageView, View.SCALE_Y, startScale, 1f));
    set.setDuration(mShortAnimationDuration);
    set.setInterpolator(new DecelerateInterpolator());
    set.addListener(new AnimatorListenerAdapter() {
        @Override
        public void onAnimationEnd(Animator animation) {
            mCurrentAnimator = null;
        }

        @Override
        public void onAnimationCancel(Animator animation) {
            mCurrentAnimator = null;
        }
    });
    set.start();
    mCurrentAnimator = set;

    // Upon clicking the zoomed-in image, it should zoom back down to the original bounds
    // and show the thumbnail instead of the expanded image.
    final float startScaleFinal = startScale;
    expandedImageView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {
            if (mCurrentAnimator != null) {
                mCurrentAnimator.cancel();
            }

            // Animate the four positioning/sizing properties in parallel, back to their
            // original values.
            AnimatorSet set = new AnimatorSet();
            set
                    .play(ObjectAnimator.ofFloat(expandedImageView, View.X, startBounds.left))
                    .with(ObjectAnimator.ofFloat(expandedImageView, View.Y, startBounds.top))
                    .with(ObjectAnimator
                            .ofFloat(expandedImageView, View.SCALE_X, startScaleFinal))
                    .with(ObjectAnimator
                            .ofFloat(expandedImageView, View.SCALE_Y, startScaleFinal));
            set.setDuration(mShortAnimationDuration);
            set.setInterpolator(new DecelerateInterpolator());
            set.addListener(new AnimatorListenerAdapter() {
                @Override
                public void onAnimationEnd(Animator animation) {
                    thumbView.setAlpha(1f);
                    expandedImageView.setVisibility(View.GONE);
                    mCurrentAnimator = null;
                }

                @Override
                public void onAnimationCancel(Animator animation) {
                    thumbView.setAlpha(1f);
                    expandedImageView.setVisibility(View.GONE);
                    mCurrentAnimator = null;
                }
            });
            set.start();
            mCurrentAnimator = set;
        }
    });
}

XML文件:

<FrameLayout>

    <ScrollView>

        <LinearLayout>
             <ImageButton />
        </LinearLayout>

    </ScrollView>

    <ImageView>

</FrameLayout>

1 个答案:

答案 0 :(得分:0)

您必须将您的imageview添加到scrollview中。并且不要忘记使scrollview可以垂直和水平滚动。我认为它会起作用