我正在使用 NSTask,但是当我启动任务时它会阻塞主线程(因此我无法更新它)直到任务结束。这是我的代码:
NSString *hostsforping = @"google.es";
pingdata = [[NSTask alloc] init];
[pingdata setLaunchPath: @"/sbin/ping"];
NSArray *pingargs;
pingargs = [NSArray arrayWithObjects: @"-c 5", hostsforping, nil];
[pingdata setArguments: pingargs];
NSPipe *pingpipe;
pingpipe = [NSPipe pipe];
[pingdata setStandardOutput: pingpipe];
NSFileHandle *pingfile;
pingfile = [pingpipe fileHandleForReading];
[pingdata launch];
NSData *pingdata1;
pingdata1 = [pingfile readDataToEndOfFile];
NSString *pingstring;
pingstring = [[NSString alloc] initWithData: pingdata1 encoding: NSUTF8StringEncoding];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(taskDidTerminate:)
name:NSTaskDidTerminateNotification
object:nil];
}
- (void) taskDidTerminate:(NSNotification *)notification {
NSLog(@"end");
}
我一直在读到 -waitUntilExit
确实会阻塞主线程,但我没有使用它,所以我不知道我做错了什么。
最佳答案
在后台线程上运行任务,readDataToEndOfFile
阻塞主线程。
// Offload the method onto a background thread, could also use Grand Central Dispatch
[self performSelectorInBackground:@selector(startTask) withObject:nil];
- (void)startTask {
NSString *hostsforping = @"google.es";
NSTask *pingdata = [[NSTask alloc] init];
[pingdata setLaunchPath: @"/sbin/ping"];
NSArray *pingargs;
pingargs = [NSArray arrayWithObjects: @"-c 5", hostsforping, nil];
[pingdata setArguments: pingargs];
NSPipe *pingpipe;
pingpipe = [NSPipe pipe];
[pingdata setStandardOutput: pingpipe];
NSFileHandle *pingfile;
pingfile = [pingpipe fileHandleForReading];
[pingdata launch];
NSData *pingdata1;
pingdata1 = [pingfile readDataToEndOfFile];
NSString *pingstring;
pingstring = [[NSString alloc] initWithData: pingdata1 encoding: NSUTF8StringEncoding];
[[NSNotificationCenter defaultCenter] addObserver:self
selector:@selector(taskDidTerminate:)
name:NSTaskDidTerminateNotification
object:nil];
}
- (void) taskDidTerminate:(NSNotification *)notification {
// Note this is called from the background thread, don't update the UI here
NSLog(@"end");
// Call updateUI method on main thread to update the user interface
[self performSelectorOnMainThread:@selector(updateUI) withObject:nil waitUntilDone:NO];
}
关于objective-c - NSTask 阻塞主线程,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/7676508/