[英]Xamarin ImageZoom Converting from Java to C#
I've been trying to resolve this for a few days to no avail. 我一直在尝试解决这一问题,但无济于事。 I'm trying to create an ImageZoom function for Xamarin.Android, then I will move to making one for Xamarin.iOS.
我正在尝试为Xamarin.Android创建一个ImageZoom函数,然后我将转向为Xamarin.iOS创建一个ImageZoom函数。
What I'm doing is the Android example code found here: https://developer.android.com/training/animation/zoom.html 我正在做的是在这里找到的Android示例代码: https : //developer.android.com/training/animation/zoom.html
I'll include the relevant code here too: 我还将在此处包括相关代码:
Class ImageZoom
{
int mShortAnimationDuration;
private Animator mCurrentAnimator;
private void zoomImageFromThumb(final View thumbView, int imageResId) {
// If there's an animation in progress, cancel it
// immediately and proceed with this one.
mShortAnimationDuration = Android.Resource.Integer.ConfigShortAnimTime;
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;
}
});
}
}
Changing the capitalisation in letters and words is fine, and handling the Rect(). 更改字母和单词的大小写是可以的,并且可以处理Rect()。 The main problem I have is implementing the two Java Animator Listeners in C#:
我遇到的主要问题是在C#中实现两个Java Animator侦听器:
set.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
mCurrentAnimator = null;
}
@Override
public void onAnimationCancel(Animator animation) {
mCurrentAnimator = null;
}
});
& &
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;
}
});
The above gives the following error: 上面给出了以下错误:
Cannot create an instance of the abstract class or interface 'AnimatorListener'
无法创建抽象类或接口“ AnimatorListener”的实例
I understand why I get the above error but I'm not sure how to actually implement the two AnimatorListenerAdapters with just some of the methods overridden in C# to the same affect as Java. 我知道为什么会收到上述错误,但是我不确定如何使用在C#中重写的某些方法来实际实现两个AnimatorListenerAdapters,以达到与Java相同的效果。 Answers with code examples are greatly appreciated!
带有代码示例的答案深表感谢!
Just create you own ListenerAdapter and subclass it like so: 只需创建您自己的ListenerAdapter并将其子类化,如下所示:
public class MyAnimatorListenerAdapter : AnimatorListenerAdapter
{
public override void OnAnimationEnd(Animator animation)
{
base.OnAnimationEnd(animation);
//Do stuff
}
public override void OnAnimationCancel(Animator animation)
{
base.OnAnimationCancel(animation);
//Do stuff
}
}
Then just set your Listener to an instance of your new adapter 然后只需将您的Listener设置为新适配器的实例
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