在iPhone中的PageControl问题

Question

当我点击任何图像时，我有一个gridview，我发送该gridview的当前索引，以便我可以看到该图像。我正在从doucment加载图像。 下面是我的viewDidload代码。 但我的问题是什么。当我点击任何gridview项目。假设它的索引是4.我在currentpage = 4中设置它。所以当我打开这个页面。它向我展示了第四张图片。但我的页面控制器当前页面是4，但我可以看到我的图像在索引1。

- (void)viewDidLoad {
    [super viewDidLoad];

    pageControlBeingUsed = NO;
    UIImageView *subview;
    //NSArray *colors = [NSArray arrayWithObjects:[UIColor redColor], [UIColor greenColor], [UIColor orangeColor],[UIColor blueColor], nil];
    for (int i = 0; i < (NSInteger)totalImagesInGrid; i++) {
        CGRect frame;
        frame.origin.x = self.scrollView.frame.size.width * i;
        frame.origin.y = 0;
        frame.size = self.scrollView.frame.size;

        subview = [[UIImageView alloc] initWithFrame:frame];
        //subview.backgroundColor = [UIColor colorWithPatternImage:[UIImage imageNamed:[tableDataArray objectAtIndex:i]]];
        NSString *name = [tableDataArray objectAtIndex:(NSUInteger)i];
        NSFileHandle* myFileHandle = [NSFileHandle fileHandleForReadingAtPath:name];
        UIImage* loadedImage = [UIImage imageWithData:[myFileHandle readDataToEndOfFile]];
        subview.image = loadedImage;
        [self.scrollView addSubview:subview];
        [subview release];
    }
    //float count = [totalImagesInGrid floatValue];
    self.scrollView.contentSize = CGSizeMake(self.scrollView.frame.size.width * 13, self.scrollView.frame.size.height);
    self.pageControl.currentPage = (NSInteger)currentImage;
    NSLog(@"currentPage  %d",(NSInteger)currentImage);
    self.pageControl.numberOfPages = (NSInteger)totalImagesInGrid;
    NSLog(@"(NSInteger)totalImagesInGrid  %d",(NSInteger)totalImagesInGrid);
}

- (void)scrollViewDidScroll:(UIScrollView *)sender {
    if (!pageControlBeingUsed) {
        // Switch the indicator when more than 50% of the previous/next page is visible
        CGFloat pageWidth = self.scrollView.frame.size.width;
        int page = floor((self.scrollView.contentOffset.x - pageWidth / 2) / pageWidth) + 1;
        self.pageControl.currentPage = (NSInteger)currentImage + page;
        NSLog(@"Page %d",page);
    }
    NSLog(@"scrollViewDidScroll");
}

- (IBAction)changePage {
// Update the scroll view to the appropriate page
CGRect frame;
frame.origin.x = self.scrollView.frame.size.width * self.pageControl.currentPage;
frame.origin.y = 0;
frame.size = self.scrollView.frame.size;
[self.scrollView scrollRectToVisible:frame animated:YES];


pageControlBeingUsed = YES;

}

这是我的gridview，我点击（1,1）图像。

这是我的页面控制视图。但那不是我选择的图像。这是（0,1）图像，但在页面控制中看到它在索引2上。

Answer 1

使用gridview的selectedIndex设置页面索引，例如参见下面的...

- (void) gridView:(UIGridView *)grid didSelectRowAt:(int)rowIndex AndColumnAt:(int)colIndex{
    ///set Image with index of colIndex..
    int selectedIndex = (rowIndex*4)+colIndex;
    NSLog(@"\n Selected Image Index is %d",selectedIndex);
}

并且在SecondView类的viewDidLoad:中，只需在方法的最后一个方法调用你的第二个View类方法changePage

- (void)viewDidLoad {
    ////another your code
    [self changePage] 
}

我希望这可以帮到你..