在App中存取照片

1、存照片

- (void)setPhoto:(UIImage *)image{
    UIImage *image = image;
     4
    //0.5代表的是压缩率，1为不压缩，图像质量最高，0为最高压缩，图像质量最低
    NSData *imageData = UIImageJPEGRepresentation(image, 0.5);
    NSString *relativePath = @"UserPhoto.jpg";
    NSString *path = [self documentsPathForFileName:relativePath];
    NSLog(@"path %@", path);
    [imageData writeToFile:path atomically:YES];
    [[NSUserDefaults standardUserDefaults] setObject:path forKey:kUserImagePath];
    [[NSUserDefaults standardUserDefaults] synchronize];
}

- (NSString*)documentsPathForFileName:(NSString*)name{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentsPath = [paths objectAtIndex:0];
    return [documentsPath stringByAppendingPathComponent:name];
}

2、读取照片

NSString *imagePath = [[NSUserDefaults standardUserDefaults] objectForKey:kUserImagePath];
    if (imagePath) {
       image = [UIImage imageWithData:[NSData dataWithContentsOfFile:imagePath]];
    }

这里的主要思路是，将照片存入应用程序的文件下，并将路径存入NSUserDefaults

读照片时，从NSUserDefaults读出路径，之后读取照片。

该方法的来源：http://stackoverflow.com/questions/6648518/save-images-in-nsuserdefaults