| 一、创建文件 |
说明：自定义文件类，通过NSFileManager 以及NSFileHandle 实现文件的创建和copy,为了控制内存的并发使用，通过控制每次赋值的固定长度来分多次复制：
NSString * path=NSHomeDirectory();
path =[path stringByAppendingPathComponent:@"deskTop/Boby.m"]; NSString * target=NSHomeDirectory();
target =[target stringByAppendingPathComponent:@"deskTop/target.m"]; NSFileManager * manager=[NSFileManager defaultManager]; //校验并且创建文件
if(![manager fileExistsAtPath:path]){
[manager createFileAtPath:path contents:nil attributes:nil];
} if(![manager fileExistsAtPath:target]){
[manager createFileAtPath:target contents:nil attributes:nil];
}
NSDictionary * dic=[manager attributesOfItemAtPath:path error:nil]; NSFileHandle * handle=[NSFileHandle fileHandleForReadingAtPath:path];
NSFileHandle * handletTarget=[NSFileHandle fileHandleForWritingAtPath:target]; int total=(int)[dic[@"NSFileSize"] integerValue];
self.totalSize=total;
int per=50;
int count=total%per==0?total/per:total/per+1;
for(int i=0;i<count;i++){ [handle seekToFileOffset:self.nowSize];
NSData *data= [handle readDataOfLength:per]; int tem=per*(i+1);
if(tem>total){
tem=total;
} self.nowSize=tem; [handletTarget seekToEndOfFile];
[handletTarget writeData:data];
[NSThread sleepForTimeInterval:0.2]; } [handle closeFile];
[handletTarget closeFile];
| 二、设置观察者 |
说明：自定义使用者，通过设置观察者来动态观察当前文件copy的进度并展示到控制台或者输出到UI，并提供方法接口，启动文件拷贝。
- (id) initWithFile:(FileMake *)files{
self=[super init];
if(self){
self.file= files;
[self.file addObserver:self forKeyPath:@"nowSize" options:NSKeyValueObservingOptionNew context:nil];
}
return self;
}
-(void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context{
CGFloat all=self.file.totalSize;
CGFloat now=[[change objectForKey:@"new"] floatValue];
CGFloat result=now/all;
NSLog(@"%.2f",result);
//一定不能忘了销毁当前的观察者
if(result==1){
[self.file removeObserver:self forKeyPath:@"nowSize"];
}
}
- (void) begin{
[self.file startCopy];
}