NSStream

详情可官网查询NSStream用法

普通用法

• 读写文件
• 网络请求中inputStream用作request.HTTPBodyStream
• - (void)stream:(NSStream *)aStream handleEvent:(NSStreamEvent)eventCode如果设置了代理,stream内容没有处理完之前会不断调用该代理方法

BoundStream

• 写入OutPutStream的内容自动传输到InputStream

• 避免了一下子将所有内容读到内存中

  
  896380774A28944C3D7B647677947232.png

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
    
    [self setUpStreamForFile:nil];
    ...
    request.HTTPBodyStream = iStream;
    [oStream open];
    [oStream write:[data1 bytes] maxLength:data1.length];
    ...
    [oStream write:[data5 bytes] maxLength:data5.length];
    [oStream close];
}
- (void)setUpStreamForFile:(NSString *)path {
    // iStream是NSInputStream实例变量
    NSInputStream *aiStream = [[NSInputStream alloc] init];
    NSOutputStream *aoStream = [[NSOutputStream alloc] init];
    [NSStream getBoundStreamsWithBufferSize:10240 inputStream:&aiStream outputStream:&aoStream];
    iStream = aiStream;
    oStream = aoStream;
    [oStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
    [iStream scheduleInRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];
     forMode:NSDefaultRunLoopMode];
}

自定义NSInputStream

#import <Foundation/Foundation.h>

NS_ASSUME_NONNULL_BEGIN

@interface MyInputStream : NSInputStream

@property (strong, nonatomic) NSInputStream *ownStream;

@end

NS_ASSUME_NONNULL_END

#import "MyInputStream.h"

@implementation MyInputStream

- (BOOL)hasBytesAvailable {
    return [_ownStream hasBytesAvailable];
}

- (void)setDelegate:(id<NSStreamDelegate>)delegate {
}

- (NSStreamStatus)streamStatus {
    return _ownStream.streamStatus;
}

- (void)open {
    [_ownStream open];
}

- (void)close {
    [_ownStream close];
}

- (NSInteger)read:(uint8_t *)buffer maxLength:(NSUInteger)len {
    return [_ownStream read:buffer maxLength:len];
}

- (id)propertyForKey:(__unused NSString *)key {
    return nil;
}

- (BOOL)setProperty:(__unused id)property
             forKey:(__unused NSString *)key
{
    return NO;
}

- (void)scheduleInRunLoop:(__unused NSRunLoop *)aRunLoop
                  forMode:(__unused NSString *)mode
{}

- (void)removeFromRunLoop:(__unused NSRunLoop *)aRunLoop
                  forMode:(__unused NSString *)mode
{}

@end