從另一個VI控制器更改UIImageView

Question

我試圖從其他viewControllers更改UIImageView，但我不知道爲什麼圖像不會更改！這裏是我的代碼：

#import "ViewController.h" 

@class ViewController; 
@interface CoverGallery : UIViewController { 

    ViewController *mainViewController; 
} 
@property (nonatomic,retain) ViewController *mainViewController; 
- (IBAction)img1; 

.M

- (IBAction)img1 { 

    mainViewController.coverArt.image = [UIImage imageNamed:@"coverDefault.png"]; 
    [self dismissModalViewControllerAnimated:YES]; 

} 

有一個叫封面藝術在MainViewController一個UIImageView，感謝

這裏是我的按鈕操作，其視圖之間切換：

ViewController（My First view） .h

@interface ViewController : UIViewController { 
ViewController *mainViewController; 

} 

@property (nonatomic, retain) ViewController *mainViewController; 


.m : 

@synthesize mainViewController; 


- (void) CoverGallery { 

    CoverGallery *gallery = [[CoverGallery alloc] initWithNibName:@"CoverGallery" bundle:nil]; 
    gallery.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal; 
    [self presentModalViewController:gallery animated:YES]; 

//here is the problem, compiler gives me the mainViewController is not the property of CoverGallery 
gallery. mainViewController = self; 
    [gallery release]; 

} 

Answer 1

你如何初始化屬性mainViewController？當您呈現模態視圖時，您需要通過設置其屬性來將其設置爲MainViewController。 我想，你在MasterViewController這樣做：

CoverGallery *gallery = [[CoverGallery alloc]initWithNibName:@"CoverGallery" bundle:nil]; 
    gallery.masterViewContrller = self; //Set it here 
    [self presentModalViewController:gallery animated:YES]; 

我固定一個錯字.. 這：

ViewController *mainViewController; 

應該是：

MainViewController *mainViewController; 

，但你需要導入它在同一個頭文件中。