如何動態地加載圖像使用的UIScrollView

Question

我有點困惑如何完成加載動態使用圖像UIScrollview或其他物體...

！[動態顯示來自Web服務來圖片] [1]

在上面的圖像支持圖像的水平和垂直滾動。我們可以使用UIScrollview或其他物體如UICollectionView來做到這一點嗎？

下面是用於顯示圖像的7水平滾動視圖的一般代碼，

int x=10; 
int y=20; 

for (int i=1; i<=7; i++) 
{ 
    UIView *bgView=[[UIView alloc]initWithFrame:CGRectMake(x, y, 80, 80)]; 
    bgView.tag=i; 
    UIImageView *bgImgView=[[UIImageView alloc]initWithFrame:CGRectMake(1, 1, 55, 55)]; 
    bgImgView.tag=1; 
    bgImgView.image=[UIImage imageNamed:[NSString stringWithFormat:@"img_%d.png",i]]; 
    [bgView addSubview:bgImgView]; 
    [self.videoscrollview addSubview:bgView]; 
    x=x+80; 
} 
self.scrollview.contentSize=CGSizeMake(7*80, 84); 

我們可以處理與一個UIView和UIImageView像上面使用UIScrollview用於顯示圖像的方法？

我想處理UIViews大小不同，其是子視圖的UIScrollView ...

我用Google搜索，但沒有發現任何相關的東西。任何建議來處理這個？

Answer 1

感謝您的寶貴答案。我使用下面的代碼暫時解決了上述問題。

Bool isOddViewNo; // at .h文件

isOddViewNo = YES; // at viewDidLoad

int x=10; 
int y=10; 

for (int i=0; i<=15; i++) 
{ 
    if (isOddViewNo) 
    { 
     isOddViewNo=NO; 
     UIView *oddView=[[UIView alloc]initWithFrame:CGRectMake(x, y, 90, 90)]; 
     UIImageView *oddImgView=[[UIImageView alloc]initWithFrame:CGRectMake(1, 1, 85, 85)]; 
     oddImgView.image=[UIImage imageNamed:[NSString stringWithFormat:@"img_%d.png",i]]; 
     [oddView addSubview:oddImgView]; 
     [self.scrollview addSubview:oddView]; 
     x+=90; 
    } 
    else 
    { 
     isOddViewNo=YES; 
     UIView *evenView=[[UIView alloc]initWithFrame:CGRectMake(x, y, 150, 150)]; 
     UIImageView *evenImgView=[[UIImageView alloc]initWithFrame:CGRectMake(1, 1, 145, 145)]; 
     evenImgView.image=[UIImage imageNamed:[NSString stringWithFormat:@"img_%d.png",i]]; 
     [evenView addSubview:evenImgView]; 
     [self.scrollview addSubview:evenView]; 
     x+=150; 
    } 

    if ((i+1)%3==0) 
    { 
     //if added image is 4 th image 
     y+=150; 
     x=10; 
    } 

    if (y+150>self.scrollview.frame.size.height) 
    { 
     self.scrollview.contentSize=CGSizeMake(400, y+150); 
    } 
    else 
    { 
     self.scrollview.contentSize=CGSizeMake(320, self.scrollview.frame.size.height+150); 
    } 
} 

！[我在UIScrollview的每一行顯示不同大小的三個視圖。它可以水平和垂直滾動。這裏是從模擬器拍攝的屏幕截圖] [1]

Answer 2

假設你的形象的名字是喜歡：images_1/2 .../10 .../N（確保daynamic圖像從這個imagename推出）

試試這個：

int x=10; int y=20; 

for (int i=1; i<=7; i++) 
{ 
     UIView *bgView=[[UIView alloc]initWithFrame:CGRectMake(x, y, 80, 80)]; 
     bgView.tag=i; 
     UIImageView *bgImgView=[[UIImageView alloc]initWithFrame:CGRectMake(1, 1, 55, 55)]; 
     bgImgView.tag=1; 

     NSString *image = [NSString stringWithFormat:@"images_%d.png",i]; 
     bgImgView.image = [UIImage imageNamed:image]; 

    [bgView addSubview:bgImgView]; 
    [self.videoscrollview addSubview:bgView]; 
    x=x+80; 
} 

self.scrollview.contentSize=CGSizeMake(7*80, 84); 

檢查它是否正常工作，可能會起作用？

快樂編碼。

Answer 3

爲此，首先必須計算並檢查scrollview的可見區域，即contentOffset，然後您必須爲該可見部分加載對象，並在分配新對象時將其存儲在數組中。由於任何圖像移動到可見區域外，您應該從滾動視圖中移除它。 這樣，它將佔用更少的內存，並且可以加載許多圖像而不會收到內存警告。

你可以按照這篇文章得到一些提示如何從滾動視圖

添加和刪除對象

http://www.raywenderlich.com/10518/how-to-use-uiscrollview-to-scroll-and-zoom-content

Answer 4

Try this for dynamic image From NSBundle: 

NSString * resourcePath = [[NSBundle mainBundle] resourcePath]; 
NSError * error; 
NSArray * directoryContents = [[NSFileManager defaultManager] contentsOfDirectoryAtPath:resourcePath error:&error]; 
NSMutableArray *imageArray = [[NSMutableArray alloc]init]; 

for (int i=0; i<directoryContents.count; i++) { 
    NSString *pathExtension = [[directoryContents objectAtIndex:i] pathExtension]; 
    if ([pathExtension isEqualToString:@"png"] || [pathExtension isEqualToString:@"jpg"]) { 
     [imageArray addObject:[directoryContents objectAtIndex:i]]; 
    } 
} 
Now u have array of all images 

for (int i=1; i<=imageArray.count; i++) 
{ 
    UIView *bgView=[[UIView alloc]initWithFrame:CGRectMake(x, y, 80, 80)]; 
    bgView.tag=i; 
    UIImageView *bgImgView=[[UIImageView alloc]initWithFrame:CGRectMake(1, 1, 55, 55)]; 
    bgImgView.tag=1; 
    bgImgView.image=[UIImage imageNamed:[imageArray objectAtIndex:i]]; 
    [bgView addSubview:bgImgView]; 
[self.videoscrollview addSubview:bgView]; 
    x=x+80; 

} self.scrollview.contentSize = CGSizeMake（I * 80，84）;