iphone - 如何检查我是否可以使用 NSError 从包中读取图像？

Question

我需要检查图像是否被读取..我有这个代码：

[self setView];
-(void)setView{

for(int i = self.firstNumberOfImages; i <= self.lastNumberOfImages; i++)
{
    UIImage* image = [UIImage imageNamed:[NSString stringWithFormat:@"%@%d.%@",self.imageName,i,self.imageType]];
    NSLog(@"%d",i);
    [imgArray addObject:image];
}
......
}

我想添加NSError到这段代码中......我如何确定我的图像将被加载而应用程序不会崩溃？（使用NSError）10x

Answer 1

检查是否imageNamed:返回nil。

for(int i = self.firstNumberOfImages; i <= self.lastNumberOfImages; i++)
{
    UIImage* image = [UIImage imageNamed:[NSString 
                     stringWithFormat:@"%@%d.%@",self.imageName,i,self.imageType]];
    NSLog(@"%d",i);
    if (image) {
        [imgArray addObject:image];
    }
}

Answer 2

检查下面的代码

for(int i = self.firstNumberOfImages; i <= self.lastNumberOfImages; i++)
{
    UIImage* image = [UIImage imageNamed:[NSString 
                     stringWithFormat:@"%@%d.%@",self.imageName,i,self.imageType]];
    NSLog(@"%d",i);
    @try{
        [imgArray addObject:image];
    }
    @catch(exception e)
     {
        NSLog(@"ERROR");
    }
}