我有一个 gridview，我正在尝试缩放 GridView 项目单击上的图像。使用来自 google http://developer.android.com/training/animation/zoom.html 的示例我的问题是如何将 R.drawable 传递到“int imageResId”中。查看下面我的代码。
MainActivity.java
public class GridViewActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setTitle("GridView");
setContentView(R.layout.grid_view);
GridView gridview = (GridView) findViewById(R.id.gridview);
gridview.setAdapter(new ImageAdapter(this));
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.activity_grid_view, menu);
return true;
}
}
gridview.xml
<GridView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/gridview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:columnWidth="90dp"
android:numColumns="auto_fit"
android:verticalSpacing="10dp"
android:horizontalSpacing="10dp"
android:stretchMode="columnWidth"
android:gravity="center"
/>
ImageAdapter.java
public class ImageAdapter extends BaseAdapter {
private Animator mCurrentAnimator;
private int mShortAnimationDuration;
private Context mContext;
public ImageAdapter(Context c) {
mContext = c;
}
public int getCount() {
return mThumbIds.length;
}
public Object getItem(int position) {
return mThumbIds[position];
}
public long getItemId(int position) {
return 0;
}
public View getView(final int position, View convertView, ViewGroup parent) {
ImageView imageView;
if (convertView == null) {
imageView = new ImageView(mContext);
imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
} else {
imageView = (ImageView) convertView;
}
imageView.setImageResource(mThumbIds[position]);
imageView.setTag(mThumbIds[position]);
imageView.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
int id = (Integer) arg0.getTag();
zoomImageFromThumb(arg0, id);
}
});
return imageView;
}
// References to our images in res > drawable
public Integer[] mThumbIds = { R.drawable.sample_0, R.drawable.sample_1,
R.drawable.sample_2, R.drawable.sample_3, R.drawable.sample_4,
R.drawable.sample_5, R.drawable.sample_6, R.drawable.sample_7,
R.drawable.sample_8, R.drawable.sample_9, R.drawable.sample_10,
R.drawable.sample_11, R.drawable.sample_12, R.drawable.sample_13,
R.drawable.sample_14, R.drawable.sample_15, R.drawable.sample_16,
R.drawable.sample_17, R.drawable.sample_18 };
private void zoomImageFromThumb(final View thumbView, int imageResId) {
if (mCurrentAnimator != null) {
mCurrentAnimator.cancel();
}
final ImageView expandedImageView = (ImageView) thumbView.findViewById(R.id.expanded_image);
expandedImageView.setImageResource(imageResId);
final Rect startBounds = new Rect();
final Rect finalBounds = new Rect();
final Point globalOffset = new Point();
thumbView.getGlobalVisibleRect(startBounds);
thumbView.findViewById(R.id.container).getGlobalVisibleRect(finalBounds, globalOffset);
startBounds.offset(-globalOffset.x, -globalOffset.y);
finalBounds.offset(-globalOffset.x, -globalOffset.y);
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;
}
thumbView.setAlpha(0f);
expandedImageView.setVisibility(View.VISIBLE);
expandedImageView.setPivotX(0f);
expandedImageView.setPivotY(0f);
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;
final float startScaleFinal = startScale;
expandedImageView.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if (mCurrentAnimator != null) {
mCurrentAnimator.cancel();
}
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;
}
});
}
}
activity_zoom.xml
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent" >
<ImageView
android:id="@+id/expanded_image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="invisible" />
</FrameLayout>
LOGCAT:
06-14 13:58:47.667: E/AndroidRuntime(14860): FATAL EXCEPTION: main
06-14 13:58:47.667: E/AndroidRuntime(14860): java.lang.NullPointerException
06-14 13:58:47.667: E/AndroidRuntime(14860): at com.example.gridview.ImageAdapter.zoomImageFromThumb(ImageAdapter.java:79)
06-14 13:58:47.667: E/AndroidRuntime(14860): at com.example.gridview.ImageAdapter.access$0(ImageAdapter.java:72)
06-14 13:58:47.667: E/AndroidRuntime(14860): at com.example.gridview.ImageAdapter$1.onClick(ImageAdapter.java:57)
06-14 13:58:47.667: E/AndroidRuntime(14860): at android.view.View.performClick(View.java:3620)
06-14 13:58:47.667: E/AndroidRuntime(14860): at android.view.View$PerformClick.run(View.java:14292)
06-14 13:58:47.667: E/AndroidRuntime(14860): at android.os.Handler.handleCallback(Handler.java:605)
06-14 13:58:47.667: E/AndroidRuntime(14860): at android.os.Handler.dispatchMessage(Handler.java:92)
06-14 13:58:47.667: E/AndroidRuntime(14860): at android.os.Looper.loop(Looper.java:137)
06-14 13:58:47.667: E/AndroidRuntime(14860): at android.app.ActivityThread.main(ActivityThread.java:4507)
06-14 13:58:47.667: E/AndroidRuntime(14860): at java.lang.reflect.Method.invokeNative(Native Method)
06-14 13:58:47.667: E/AndroidRuntime(14860): at java.lang.reflect.Method.invoke(Method.java:511)
06-14 13:58:47.667: E/AndroidRuntime(14860): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:980)
06-14 13:58:47.667: E/AndroidRuntime(14860): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:747)
06-14 13:58:47.667: E/AndroidRuntime(14860): at dalvik.system.NativeStart.main(Native Method)
最佳答案
尝试一下，例如，您在单击的 View 中发现了扩展 View
final ImageView expandedImageView = (ImageView) findViewById(R.id.expanded_image);
expandedImageView.setImageResource(imageResId);
在 zoomImageFromThumb(final View thumbView, int imageResId)
或者您可能需要在主 fragment View 中找到该 View ，例如
final ImageView expandedImageView = (ImageView) mainView.findViewById(R.id.expanded_image);
expandedImageView.setImageResource(imageResId);
不在thumbView中.
编辑:
更改您的 gridview.xml如下，将两个 View 放在相同的布局中
<GridView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/gridview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:columnWidth="90dp"
android:numColumns="auto_fit"
android:verticalSpacing="10dp"
android:horizontalSpacing="10dp"
android:stretchMode="columnWidth"
android:gravity="center"
/>
<ImageView
android:id="@+id/expanded_image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:visibility="invisible" />
您可以对两者使用相对布局包装器，以便一个与另一个重叠
并使用
final ImageView expandedImageView = (ImageView) findViewById(R.id.expanded_image);
expandedImageView.setImageResource(imageResId);
在 zoomImageFromThumb(final View thumbView, int imageResId)
如果你找不到符号findViewById()错误，然后添加
public static Activity getActivity(){
return this;
}在GridViewActivity.java
然后使用
final ImageView expandedImageView = (ImageView) GridViewActivity.getActivity().findViewById(R.id.expanded_image);
expandedImageView.setImageResource(imageResId);
在 zoomImageFromThumb(final View thumbView, int imageResId)
关于android - GridView 缩放图像，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/16988844/