從ios中從webservie中加載圖片

Question

任何人都請幫助我， 我使用此代碼創建圖像動畫滑塊，圖像從webservice獲取，當我通過使用objectatindex加載圖像時：i圖像只加載1,2 ，...沒有加載到第0個索引，我做了什麼錯誤，我不知道，請提前引導我，謝謝，這裏是代碼。

-(void)viewDidLoad { 
    [super viewDidLoad]; 



NSURL *blogURL = [NSURL URLWithString:@"http://www.example.com/apps/mainslider.php"]; 

NSData *jsonData = [NSData dataWithContentsOfURL:blogURL]; 

NSError *error = nil; 

NSArray *dataDictionary = [NSJSONSerialization JSONObjectWithData:jsonData options:0 error:&error]; 


data = [dataDictionary valueForKey:@"slider_image"]; 




UIScrollView *scr=[[UIScrollView alloc] initWithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height)]; 
scr.tag = 1; 
scr.autoresizingMask=UIViewAutoresizingNone; 
[self.view addSubview:scr]; 
[self setupScrollView:scr]; 
UIPageControl *pgCtr = [[UIPageControl alloc] init ];//WithFrame:CGRectMake(0, 0, self.view.frame.size.width, self.view.frame.size.height+40)];//0, 264, 480, 36 
[pgCtr setTag:12]; 
pgCtr.numberOfPages=0; 
pgCtr.autoresizingMask=UIViewAutoresizingNone; 
[self.view addSubview:pgCtr]; 

UIButton *button = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
[button addTarget:self 
      action:@selector(buttonClicked:) 
forControlEvents:UIControlEventTouchUpInside]; 
[button setTitle:@"Skip" forState:UIControlStateNormal]; 
[button setBackgroundColor:[UIColor colorWithRed:247/255.0 green:183/255.0 blue:25/255.0 alpha:1]]; 
[button setTitleColor:[UIColor whiteColor] forState:UIControlStateNormal]; 

button.frame = CGRectMake(80.0, 490, 160.0, 40.0); 

[self.view addSubview:button]; 


} 


-(void)setupScrollView:(UIScrollView*)scrMain { 



for (int i=0; i<data.count; i++) { 
    // create image 




    image = [UIImage imageWithData: 
         [NSData dataWithContentsOfURL: 
         [NSURL URLWithString:[NSString stringWithFormat:@"http://www.example.com/uploads/appbanners/%@",[data objectAtIndex:i]]]]]; 

    // create imageView 
    UIImageView *imgV = [[UIImageView alloc] initWithFrame:CGRectMake((i-1)*scrMain.frame.size.width, 0, scrMain.frame.size.width, scrMain.frame.size.height)]; 
    // set scale to fill 
    imgV.contentMode=UIViewContentModeScaleToFill; 
    // set image 
    [imgV setImage:image]; 
    // apply tag to access in future 
    imgV.tag=i+1; 
    // add to scrollView 
    [scrMain addSubview:imgV]; 


} 
// set the content size to 10 image width 
[scrMain setContentSize:CGSizeMake(scrMain.frame.size.width*[data count], scrMain.frame.size.height)]; 
// enable timer after each 2 seconds for scrolling. 
[NSTimer scheduledTimerWithTimeInterval:8 target:self selector:@selector(scrollingTimer) userInfo:nil repeats:YES]; 

} 

- (void)scrollingTimer { 
// access the scroll view with the tag 
UIScrollView *scrMain = (UIScrollView*) [self.view viewWithTag:1]; 
// same way, access pagecontroll access 
UIPageControl *pgCtr = (UIPageControl*) [self.view viewWithTag:12]; 
// get the current offset (which page is being displayed) 
CGFloat contentOffset = scrMain.contentOffset.x; 
// calculate next page to display 
int nextPage = (int)(contentOffset/scrMain.frame.size.width) + 1 ; 
// if page is not 10, display it 
if(nextPage!=imagesCount) { 
    [scrMain scrollRectToVisible:CGRectMake(nextPage*scrMain.frame.size.width, 0, scrMain.frame.size.width, scrMain.frame.size.height) animated:YES]; 
    pgCtr.currentPage=nextPage; 

} else { 
    [scrMain scrollRectToVisible:CGRectMake(0, 0, scrMain.frame.size.width, scrMain.frame.size.height) animated:YES]; 
    pgCtr.currentPage=0; 
} 



} 

Answer 1

由於@Uttah辛哈已經指出，你已經創建的CGRect的圖像看起來是錯誤代碼......

// create imageView 
UIImageView *imgV = [[UIImageView alloc] initWithFrame:CGRectMake((i-1)*scrMain.frame.size.width, 0, scrMain.frame.size.width, scrMain.frame.size.height)]; 

應該

// create imageView 
UIImageView *imgV = [[UIImageView alloc] initWithFrame:CGRectMake((i)*scrMain.frame.size.width, 0, scrMain.frame.size.width, scrMain.frame.size.height)]; 

你是也會打標籤的UIImageView的方式問題，當i是1 scrollView和ImageView將有相同的tag號碼，這也將是tr如果你有超過12張圖像。您可能需要考慮爲ImageView添加偏移量，例如

imgV.tag=i+100;