Question

以下代码适用于模拟器，但崩溃了设备，因为img为nil：

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];

    for (NSString* path in userImages) {
        NSLog(@"image at %@", path); //logs "image at userImage0.png"
        NSString *getImagePath = [documentsDirectory stringByAppendingPathComponent:path];
        UIImage *img = [UIImage imageWithContentsOfFile:getImagePath];
        unichar ch = [path characterAtIndex:9];
        NSLog(@"Ch = %c", ch); //correctly logs "0"
        if (ch == '0') {
            [self.images insertObject:img atIndex:0]; //this throws the error
        }
    }

为什么在设备上运行而不是在模拟器上运行时是img nil？图像最初保存如下：

NSString *docsDir = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask,YES) objectAtIndex:0];
NSString *imageName = @"userimage0.png";
NSString *imagePath = [docsDir stringByAppendingPathComponent:imageName];
[UIImagePNGRepresentation(img) writeToFile:imagePath atomically:YES];

Answer 1

抱歉，这是大写问题。 userimage vs userImage。模拟器并不关心（我希望它能做到），但设备确实如此。

NSDocumentDirectory合法保存和加载设备上的图像？

1 个答案: