objective-c - 可可问题 - NSTask 不起作用

Question

NSTask 不工作；我认为这与论点有关。这是我的代码：

 - (IBAction)downloadFile:(id)sender {

    // allocate our stuff :D
    progressIndication = [[NSProgressIndicator alloc] init];
    NSTask *downloader = [[NSTask alloc] init];

    // set up the downloader task
    [downloader setLaunchPath:@"/usr/bin/curl"];
    [downloader setArguments:[NSArray arrayWithObject:[NSString stringWithFormat:@"-LO %@", downloadURL]]];

    // go to the Desktop!
    system("cd ~/Desktop");

    // start progress indicator
    [progressIndication startAnimation:self];

    // download!
    [downloader launch];

    // stop the progress indicator, everything is done! :D
    [progressIndication stopAnimation:self];



}

谢谢

Answer 1

您真的不需要使用curl来执行此操作；只需使用NSData来更轻松地完成任务：

NSData *data = [NSData dataWithContentsOfURL:downloadURL];
[data writeToFile:[[NSString stringWithFormat:@"~/Desktop/%@", [downloadURL lastPathComponent]] stringByExpandingTildeInPath] atomically:YES];

---

如果你坚持你需要使用curl它，你将不得不修复你的代码，这有几个原因不起作用。首先，你的论点是错误的。您应该有以下代码：

[downloader setArguments:[NSArray arrayWithObjects:@"-L", @"-O", [downloadURL absoluteString], @"-o", [NSString stringWithFormat:@"~/Desktop/%@", [downloadURL lastPathComponent]], nil];

二system("cd ~/Desktop")是无意义；摆脱它。
最后，NSTask并发运行。[downloader launch]开始操作，您的代码继续。它应该是：

[downloader launch];
[downloader waitUntilExit]; // block until download completes
[progressIndication stopAnimation:self];