How to get file size properly and convert it to MB, GB in Cocoa? [duplicate]

Answer 1

For converting file size to MB, Gb use below function

- (id)transformedValue:(id)value
{
    
    double convertedValue = [value doubleValue];
    int multiplyFactor = 0;
    
    NSArray *tokens = @[@"bytes",@"KB",@"MB",@"GB",@"TB",@“PB”, @“EB”, @“ZB”, @“YB”];
    
    while (convertedValue > 1024) {
        convertedValue /= 1024;
        multiplyFactor++;
    }
    
    return [NSString stringWithFormat:@"%4.2f %@",convertedValue, tokens[multiplyFactor]];
}

EDIT:

You can also use NSByteCountFormatter class. Available in iOS 6.0 / OS X v10.8 and later.

[NSByteCountFormatter stringFromByteCount:1999 countStyle:NSByteCountFormatterCountStyleFile];

You can use NSByteCountFormatterCountStyleFile, NSByteCountFormatterCountStyleMemory, NSByteCountFormatterCountStyleDecimal or NSByteCountFormatterCountStyleBinary in countStyle.

NSByteCountFormatterCountStyleFile: Specifies display of file or storage byte counts. The actual behavior for this is platform-specific; on OS X 10.8, this uses the decimal style, but that may change over time.

NSByteCountFormatterCountStyleMemory: Specifies display of memory byte counts. The actual behavior for this is platform-specific; on OS X 10.8, this uses the binary style, but that may change over time.

NSByteCountFormatterCountStyleDecimal: Specifies the number of bytes for KB explicitly, 1000 bytes are shown as 1 KB

NSByteCountFormatterCountStyleBinary: Specifies the number of bytes for KB explicitly, 1024 bytes are shown as 1 KB