我正在创建一个应用程序，其中我将UIScrollView作为图像旋转器放在一个页面中，我们可以像图像滚动器一样看到两个图像。图像滚动为一种水平的方式。
现在问题是我想将中间图像显示为高亮显示。当图像围绕像素120时，图像将突出显示或弹出或类似选择。
请帮助我...... Thanx提前
答案 0 :(得分：0)
您应该在旋转中使用两个图像视图，即将图像视图的图像设置为阵列中的下两个图像。这比使用10个imageview并用图像填充它们会节省大量内存。下面是一次显示一个图像的照片滚动条的代码，您应该能够根据需要更改框架宽度以显示两个。
一些常数：
//Portrait Image will have less width in landscape
#define kLandscapeImageHeight 300
#define kLandscapeImageWidth 208
//Landscape will have less height in portrait
#define kPortraitImageHeight 213
#define kPortraitImageWidth 320
#define kLandscapImageX 136
#define kPortraitImageY 134
初始化：
scrollView.contentSize = CGSizeMake([imageArray count]*320, scrollView.frame.size.height);
if ([imageArray count] >= 1) {
view1 = [[UIImageView alloc] init];
UIImage *view1Image = [imageArray objectAtIndex:imageToOpen];
//Photo was taken in portrait
if (view1Image.size.width < view1Image.size.height) {
view1.frame = CGRectMake(imageToOpen*320, 0, 320, 460);
}
//Photo was taken in landscape
else {
view1.frame = CGRectMake(imageToOpen*320, kPortraitImageY, 320, kPortraitImageHeight);
}
view1.image = view1Image;
[scrollView addSubview:view1];
view2 = [[UIImageView alloc] init];
if ([imageArray count] != 1) {
if (imageToOpen < [imageArray count]-1) {
UIImage *view2Image = [imageArray objectAtIndex:(imageToOpen+1)];
//Photo was taken in portrait mode
if (view2Image.size.width < view2Image.size.height) {
view2.frame = CGRectMake((imageToOpen+1)*320, 0, 320, scrollView.frame.size.height);
}
//Photo was taken in landscape mode
else {
view2.frame = CGRectMake((imageToOpen+1)*320, kPortraitImageY, 320, kPortraitImageHeight);
}
view2.image = view2Image;
[scrollView addSubview:view2];
}
else if (imageToOpen == [imageArray count]-1) {
UIImage *view2Image = [imageArray objectAtIndex:(imageToOpen-1)];
//Photo was taken in portrait mode
if (view2Image.size.width < view2Image.size.height) {
view2.frame = CGRectMake((imageToOpen-1)*320, 0, 320, scrollView.frame.size.height);
}
//Photo was taken in landscape mode
else {
view2.frame = CGRectMake((imageToOpen-1)*320, kPortraitImageY, 320, kPortraitImageHeight);
}
view2.image = [imageArray objectAtIndex:imageToOpen-1];
[scrollView addSubview:view2];
}
}
//For some reason, same function with animated 'NO' behaves differently!!!
[scrollView scrollRectToVisible:view1.frame animated:YES];
}
现在实现scrollView委托方法scrollViewDidScroll：在其中您将识别哪个图像将成为下一个图像并突出显示它。 'nextView'始终指向将在屏幕上显示的imageView。您可以将页面宽度减小到160，因为您希望一次显示两个图像：
- (void)scrollViewDidScroll:(UIScrollView *) scrollView {
[self hideBars];
UIInterfaceOrientation orientation = self.interfaceOrientation;
CGFloat pageWidth;
if (orientation == UIInterfaceOrientationPortraitUpsideDown || orientation == UIInterfaceOrientationPortrait) {
pageWidth = 320;
}
else if (orientation == UIInterfaceOrientationLandscapeLeft || orientation == UIInterfaceOrientationLandscapeRight) {
pageWidth = 480;
}
float currPos = self.scrollView.contentOffset.x ;
int selectedPage = roundf(currPos / pageWidth);
float truePosition = selectedPage*pageWidth;
int zone = selectedPage % 2;
BOOL view1Active = zone == 0;
UIImageView *nextView = view1Active ? view2 : view1;
int nextpage = truePosition > currPos ? selectedPage-1 : selectedPage+1;
if(nextpage >= 0 && nextpage < [imageArray count])
{
if((view1Active && nextpage == view1Index) || (!view1Active && nextpage == view2Index)) return;
UIImage *nextViewImage = [imageArray objectAtIndex:nextpage];
if (orientation == UIInterfaceOrientationPortraitUpsideDown || orientation == UIInterfaceOrientationPortrait) {
if (nextViewImage.size.width < nextViewImage.size.height) {
nextView.frame = CGRectMake(nextpage*320, 0, 320, 480);
}
else {
nextView.frame = CGRectMake(nextpage*320, kPortraitImageY, 320, kPortraitImageHeight);
}
}
else if (orientation == UIInterfaceOrientationLandscapeLeft || orientation == UIInterfaceOrientationLandscapeRight) {
if (nextViewImage.size.width < nextViewImage.size.height) {
nextView.frame = CGRectMake(nextpage*480+kLandscapImageX, 0, kLandscapeImageWidth, kLandscapeImageHeight);
}
else {
nextView.frame = CGRectMake(nextpage*480, 0, 480, 300);
}
}
nextView.image = nextViewImage;
if(view1Active) view1Index = nextpage;
else view2Index = nextpage;
}
}
如果您的UI支持两种方向：
- (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation {
// Return YES for supported orientations
return YES;//(interfaceOrientation == UIInterfaceOrientationLandscapeLeft);
}
- (void)willRotateToInterfaceOrientation:(UIInterfaceOrientation)toInterfaceOrientation duration:(NSTimeInterval)duration {
int selectedPage = 0;
//if scrollview is scrolled till the last page
if (toInterfaceOrientation == UIInterfaceOrientationLandscapeRight || toInterfaceOrientation == UIInterfaceOrientationLandscapeLeft) {
if (scrollView.contentOffset.x >= ([imageArray count]-1)*320) {
selectedPage = [imageArray count]-1;
}
}
else if (toInterfaceOrientation == UIInterfaceOrientationPortrait || toInterfaceOrientation == UIInterfaceOrientationPortraitUpsideDown) {
if (scrollView.contentOffset.x >= ([imageArray count]-1)*480) {
selectedPage = [imageArray count]-1;
}
}
if (selectedPage != [imageArray count]-1) {
//condition doesnt apply for last page
if (view1.frame.origin.x < view2.frame.origin.x) {
//View 1 is at the front
selectedPage = [imageArray indexOfObject:view1.image];
}
else {
//View 2 is at the front
selectedPage = [imageArray indexOfObject:view2.image];
}
}
int zone = selectedPage % 2;
BOOL view1Active = zone == 0;
UIImageView *thisView = view1Active ? view1 : view2;
UIImageView *nextView = view1Active ? view2 : view1;
NSLog(@"Selected Page = %d", selectedPage);
if (toInterfaceOrientation == UIInterfaceOrientationLandscapeRight || toInterfaceOrientation == UIInterfaceOrientationLandscapeLeft) {
scrollView.contentSize = CGSizeMake([imageArray count]*480, kLandscapeImageHeight);
if ([imageArray count] != 1) {
if (/*thisView.frame.origin.x < nextView.frame.origin.x && */(selectedPage+1) != [imageArray count]) {
UIImage *nextViewImage = [imageArray objectAtIndex:selectedPage+1];
if (nextViewImage.size.width < nextViewImage.size.height) {
nextView.frame = CGRectMake((selectedPage+1)*480+kLandscapImageX, 0, kLandscapeImageWidth, kLandscapeImageHeight);
}
else {
nextView.frame = CGRectMake((selectedPage+1)*480, 0, 480, 300);
}
[nextView setImage:nextViewImage];
}
else {
UIImage *nextViewImage = [imageArray objectAtIndex:selectedPage-1];
if (nextViewImage.size.width < nextViewImage.size.height) {
nextView.frame = CGRectMake((selectedPage-1)*480+kLandscapImageX, 0, kLandscapeImageWidth, kLandscapeImageHeight);
}
else {
nextView.frame = CGRectMake((selectedPage-1)*480, 0, 480, 300);
}
[nextView setImage:nextViewImage];
}
}
UIImage *thisViewImage = [imageArray objectAtIndex:selectedPage];
if (thisViewImage.size.width < thisViewImage.size.height) {
//[thisView setFrame:CGRectMake((selectedPage*480)+kLandscapImageX, 0, kLandscapeImageWidth, kLandscapeImageHeight)];
thisView.frame = CGRectMake((selectedPage*480)+kLandscapImageX, 0, kLandscapeImageWidth, kLandscapeImageHeight);
}
else {
[thisView setFrame:CGRectMake(selectedPage*480, 0, 480, 300)];
}
[thisView setImage:thisViewImage];
[scrollView setContentOffset:CGPointMake(selectedPage*480, 0) animated:YES];
}
else if (toInterfaceOrientation == UIInterfaceOrientationPortrait || toInterfaceOrientation == UIInterfaceOrientationPortraitUpsideDown) {
scrollView.contentSize = CGSizeMake([imageArray count]*320, 460);
if ([imageArray count] != 1) {
if (/*thisView.frame.origin.x < nextView.frame.origin.x && */(selectedPage+1) != [imageArray count]) {
UIImage *nextViewImage = [imageArray objectAtIndex:selectedPage+1];
if (nextViewImage.size.width < nextViewImage.size.height) {
//[nextView setFrame:CGRectMake((selectedPage+1)*320, 0, 320, 460)];
nextView.frame = CGRectMake((selectedPage+1)*320, 0, 320, 460);
}
else {
nextView.frame = CGRectMake((selectedPage+1)*320, kPortraitImageY, 320, kPortraitImageHeight);
}
[nextView setImage:nextViewImage];
}
else {
UIImage *nextViewImage = [imageArray objectAtIndex:selectedPage-1];
if (nextViewImage.size.width < nextViewImage.size.height) {
[nextView setFrame:CGRectMake((selectedPage-1)*320, 0, 320, 460)];
}
else {
nextView.frame = CGRectMake((selectedPage-1)*320, kPortraitImageY, 320, kPortraitImageHeight);
}
[nextView setImage:nextViewImage];
}
}
UIImage *thisViewImage = [imageArray objectAtIndex:selectedPage];
if (thisViewImage.size.width < thisViewImage.size.height) {
[thisView setFrame:CGRectMake(selectedPage*320, 0, 320, 460)];
}
else {
[thisView setFrame:CGRectMake(selectedPage*320, kPortraitImageY, 320, kPortraitImageHeight)];
}
[thisView setImage:thisViewImage];
//For some reason, same function with animated 'NO' behaves differently!!!
[scrollView setContentOffset:CGPointMake(selectedPage*320, 0) animated:YES];
//this function doesnt work properly becase it doesnt dcroll if the rect is already visible. So photos load like half of one and half of the other
//[scrollView scrollRectToVisible:CGRectMake(selectedPage*320, 0, 320, scrollView.frame.size.height) animated:YES];
}
}