小编Ran*_*ens的帖子

我在4.4.2,尝试通过uri删除文件(图像).这是我的代码:

File file = new File(uri.getPath());
boolean deleted = file.delete();
if(!deleted){
      boolean deleted2 = file.getCanonicalFile().delete();
      if(!deleted2){
           boolean deleted3 = getApplicationContext().deleteFile(file.getName());
      }
}

目前,这些删除功能都没有实际删除该文件.我的AndroidManifest.xml中也有这个:

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_INTERNAL_STORAGE" />

我有一个带有列表的NavigationView。如何更改NavigationView的颜色？

目前我正在使用Swift on Xcode 6 beta 7为iPad(iOS7)构建一个WebRTC应用程序.我一直收到这些错误.我添加了错误的库吗？它无法找到它们吗？

以下是它打印的错误:

    Undefined symbols for architecture armv7:
  "std::string::_Rep::_S_empty_rep_storage", referenced from:
      +[RTCMediaConstraints constraintsFromArray:] in libjingle_peerconnection_objc.a(RTCMediaConstraints.o)
      std::vector<webrtc::MediaConstraintsInterface::Constraint, std::allocator<webrtc::MediaConstraintsInterface::Constraint> >::_M_insert_aux(__gnu_cxx::__normal_iterator<webrtc::MediaConstraintsInterface::Constraint*, std::vector<webrtc::MediaConstraintsInterface::Constraint, std::allocator<webrtc::MediaConstraintsInterface::Constraint> > >, webrtc::MediaConstraintsInterface::Constraint const&) in libjingle_peerconnection_objc.a(RTCMediaConstraints.o)
  "std::string::assign(std::string const&)", referenced from:
      std::vector<webrtc::MediaConstraintsInterface::Constraint, std::allocator<webrtc::MediaConstraintsInterface::Constraint> >::_M_insert_aux(__gnu_cxx::__normal_iterator<webrtc::MediaConstraintsInterface::Constraint*, std::vector<webrtc::MediaConstraintsInterface::Constraint, std::allocator<webrtc::MediaConstraintsInterface::Constraint> > >, webrtc::MediaConstraintsInterface::Constraint const&) in libjingle_peerconnection_objc.a(RTCMediaConstraints.o)
      webrtc::MediaConstraintsInterface::Constraint* std::__copy_backward<false, std::random_access_iterator_tag>::__copy_b<webrtc::MediaConstraintsInterface::Constraint*, webrtc::MediaConstraintsInterface::Constraint*>(webrtc::MediaConstraintsInterface::Constraint*, webrtc::MediaConstraintsInterface::Constraint*, webrtc::MediaConstraintsInterface::Constraint*) in libjingle_peerconnection_objc.a(RTCMediaConstraints.o)
      webrtc::MediaConstraintsInterface::Constraint* std::__copy<false, std::random_access_iterator_tag>::copy<webrtc::MediaConstraintsInterface::Constraint*, webrtc::MediaConstraintsInterface::Constraint*>(webrtc::MediaConstraintsInterface::Constraint*, webrtc::MediaConstraintsInterface::Constraint*, webrtc::MediaConstraintsInterface::Constraint*) in libjingle_peerconnection_objc.a(RTCMediaConstraints.o)
      webrtc::MediaConstraintsInterface::Constraint* std::__copy<false, std::random_access_iterator_tag>::copy<webrtc::MediaConstraintsInterface::Constraint const*, webrtc::MediaConstraintsInterface::Constraint*>(webrtc::MediaConstraintsInterface::Constraint const*, webrtc::MediaConstraintsInterface::Constraint const*, webrtc::MediaConstraintsInterface::Constraint*) in libjingle_peerconnection_objc.a(RTCMediaConstraints.o)
  "std::string::_Rep::_M_destroy(std::allocator<char> const&)", referenced from:
      +[RTCMediaConstraints constraintsFromArray:] in libjingle_peerconnection_objc.a(RTCMediaConstraints.o) …

我创建了一个按钮，但由于某种原因，触摸无法识别：

override func viewDidLoad() {
        super.viewDidLoad()

        var settingsButton = UIButton.buttonWithType(UIButtonType.System) as UIButton
        settingsButton.frame = CGRectMake(self.view.frame.size.width - 50, 35, 35, 35)
        settingsButton.setImage(UIImage(named: "settings-button"), forState: UIControlState.Normal)
        settingsButton.addTarget(self, action: Selector("settingsButtonPressed"), forControlEvents: UIControlEvents.TouchUpInside)

        self.view.addSubview(settingsButton)
}

func settingsButtonPressed(){
        println("Settings selected")
}

我没有收到任何错误，只是在我触摸按钮时没有注册。我也试过制作一个 UIButtonType.Custom 类型的按钮，我试过选择器作为

Selector("settingsButtonPressed")
Selector("settingsButtonPressed:") //I changed the function to settingsButtonPressed(sender: UIButton)
"settingsButtonPressed"
"settingsButtonPressed:" //I changed the function to settingsButtonPressed(sender: UIButton)

我已将图像添加到文本字段,并希望再次将其删除.我试过以下两行无济于事？

string = string.stringByReplacingOccurrencesOfString("\\U0000fffc", withString: "", options: NSStringCompareOptions.LiteralSearch, range: nil)
string = string.stringByReplacingOccurrencesOfString("\U0000fffc", withString: "", options: NSStringCompareOptions.LiteralSearch, range: nil)

非常感谢任何帮助,非常感谢!