Question

我知道有很多问题已经提到了类似的问题。请不要低估或关闭问题。我刚刚尝试实施针对这些问题的解决方案。没有什么对我有用。我的情况也略有不同。在这里：

我的应用包含图片库。它是一个滚动视图，显示从sqlite db中检索到的图片。用户可以滚动图像，添加或删除图像等。我可以动态地将图片添加到图库。但是当我需要实现删除功能时，问题就出现了。我使用以下代码，但即使在调用removeFromSuperView之后，图像也没有从滚动视图中删除。

-(void)deleteDeck{ 

if(selectedEditDeck!=0){
    [deck deleteSelectedDeck:selectedEditDeck]; //deleting from database

   //problem starts here ***
    [(UIImageView*)[decksGallery viewWithTag:selectedEditDeck-1]removeFromSuperview];
    [self loadGallery];
    selectedEditDeck=0;
  //Ends here*****

    [tableData release];
    tableData=[NSMutableArray array];
    [self showCardNamesinTable];
    [aTableView reloadData];
}

我已经在loadview方法中创建了uiscrollview。然后在每次删除和添加图像后刷新视图以便我可以显示更新的图库，我使用以下代码：

-(void)loadGallery{                                                                                //Reloading all for adding a single deck image.

//Database part****
NSString *sqlStr = [NSString stringWithFormat:@"select first_card from decksTable"]; 
char *sql = (char*)[sqlStr UTF8String];
kidsFlashCardAppDelegate *appDelegate = [[UIApplication sharedApplication] delegate];
NSMutableArray *galleryImagesArray=[appDelegate.dbConnection fetchColumnFromTable:sql col:0];
NSArray *sysPaths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask,YES);
NSString *docDirectory = [sysPaths objectAtIndex:0];
numberofImages = [galleryImagesArray count];
printf("number is %d",numberofImages);//Database part of code ends here

//在下面的代码片段中，我将图像添加到UIscrollView

    for (int i = 0; i < [galleryImagesArray count]; i++) {
    CGFloat yOrigin = i * 65;
    NSString *filePath = [NSString stringWithFormat:@"%@/%@", docDirectory,[galleryImagesArray objectAtIndex:i]];
    galleryImage = [[UIImageView alloc] initWithFrame:CGRectMake(yOrigin+140, 15,50,50 )];
    //galleryImage.tag=[galleryImagesArray count];
    galleryImage.tag=i;
    printf("THE TAG IS %d",galleryImage.tag);
    galleryImage.clipsToBounds=YES;
    galleryImage.layer.cornerRadius=11.0;
    galleryImage.backgroundColor=[UIColor clearColor];
    galleryImage.image =[UIImage imageWithContentsOfFile:filePath];
    [decksGallery addSubview:galleryImage];
    [galleryImage release];
}
decksGallery.contentSize = CGSizeMake(115*[galleryImagesArray count], 80);
//[decksGallery reloadInputViews];

Answer 1

确保您的[decksGallery viewWithTag:selectedEditDeck-1]没有返回nil，并且在刷新代码运行之前，图像实际上已从数据库中删除。

此外，您在创建代码中设置了imageView.tag = i;，因为i为0，这是每个UIView的标记默认值，您可以更好地修复你的创作代码也是如此。

Answer 2

如果您只想从imageView中删除图像，还可以执行imageView.image = nil;

UIImageView*imageView = (UIImageView*)[decksGallery viewWithTag:selectedEditDeck-1];
[imageView removeFromSuperview];
imageView = nil;

从UIScrollView中删除UIImageView

2 个答案: