␡
- Accessing Basic Device Information
- Adding Device Capability Restrictions
- Recipe: Checking Device Proximity and Battery States
- Recipe: Recovering Additional Device Information
- Recipe: Using Acceleration to Locate "Up"
- Working with Basic Orientation
- Retrieving the Current Accelerometer Angle Synchronously
- Recipe: Using Acceleration to Move Onscreen Objects
- Recipe: Accelerometer-Based Scroll View
- Recipe: Core Motion Basics
- Recipe: Retrieving and Using Device Attitude
- Detecting Shakes Using Motion Events
- Recipe: Using External Screens
- Tracking Users
- One More Thing: Checking for Available Disk Space
- Summary
This chapter is from the book
This chapter is from the book
This chapter is from the book
This chapter is from the book
One More Thing: Checking for Available Disk Space
The NSFileManager class enables you to determine how much space is free on the iPhone and how much space is provided on the device as a whole. Listing 1-1 demonstrates how to check for these values and show the results using a friendly comma-formatted string. The values returned represent the free space in bytes.
Listing 1-1. Recovering File System Size and File System Free Size
- (NSString *) commaFormattedStringWithLongLong: (long long) num
{
// Produce a properly formatted number string
// Alternatively use NSNumberFormatter
if (num < 1000)
return [NSString stringWithFormat:@"%d", num];
return [[self commasForNumber:num/1000]
stringByAppendingFormat:@",%03d", (num % 1000)];
}
- (void) action: (UIBarButtonItem *) bbi
{
NSFileManager *fm = [NSFileManager defaultManager];
NSDictionary *fattributes =
[fm fileSystemAttributesAtPath:NSHomeDirectory()];
NSLog(@"System space: %@",
[self commaFormattedStringWithLongLong:[[fattributes
objectForKey:NSFileSystemSize] longLongValue]]);
NSLog(@"System free space: %@",
[self commasForNumber:[[fattributes
objectForKey:NSFileSystemFreeSize] longLongValue]]);
}