学步园

1、NSData 互转 int

int test=
15; 
NSString*strTest
=[NSString stringWithFormat:@"%d",test]; 
NSData*strData=[strTest
dataUsingEncoding:NSUTF8StringEncoding]; 
[strData writeToFile:[documentsDirectory stringByAppendingString:@"someFile"]
atomically:YES];

NSData* strData=[NSData
dataWithContentsOfFile:[documentsDirectory stringByAppendingString:@"someFile"]]; 
NSString*strTest=[[NSString
alloc] initWithData:strData encoding:NSUTF8StringEncoding]; 
int test=[strTest intValue];

写入

int i = 1;

NSData *data = [NSData dataWithBytes: &i length: sizeof(i)];

读出

int i;

[data getBytes: &i length: sizeof(i)];