設置視網膜背景圖像出現在

Question

我設置一個隨機的背景圖片爲我的應用程序通過加載圖像並將其添加到我的視圖縮放：

UIImageView *background = [[UIImageView alloc] 
           initWithImage:[UIImage imageNamed: 
           [NSString stringWithFormat:@"bg%u.jpg", 1+arc4random_uniform(15)]]]; 
    [self.view addSubview:background]; 
    [self.view sendSubviewToBack:background]; 

我的圖片640x1136在326 PPI，但圖像出於某種原因放大。任何想法爲什麼會被讚賞。

模擬器

實際圖像：

感謝。

Answer 1

這是因爲你的Alloc與你的形象初始化，不與固定大小。

int screenHeight = [UIScreen mainScreen].bounds.size.height; 
int screenWidth = [UIScreen mainScreen].bounds.size.width; 


UIImageView *background = [[UIImageView alloc]initWithFrame:CGRectMake(0, 0, screenWidth, screenHeight)]; 

background.image = [UIImage imageNamed:[NSString stringWithFormat:@"bg%u.jpg",1+arc4random_uniform(15)]] 

[self.view addSubview:background]; 
[self.view sendSubviewToBack:background]; 

做這樣的

Answer 2

嗨嘗試這樣，

UIImageView *background = [[UIImageView alloc] 
           initWithImage:[UIImage imageNamed: 
           [NSString stringWithFormat:@"bg%u.jpg", 1+arc4random_uniform(15)]]]; 

    background.frame = self.view.frame; // this is the only line you have missed 
    [self.view addSubview:background]; 
    [self.view sendSubviewToBack:background];