NSOpenPanel - 不推荐使用？

Question

我一直试图让一个窗口出现，要求人选择一个文件，我最终做到了。问题是，Xcode抱怨我正在使用的方法已被弃用。我查看了class reference，但在“运行面板”部分下的所有内容在Mac OS 10.6以前都已弃用。我现在应该使用不同的课程吗？

Answer 1

据我所知，您可以使用runModal方法如下所示：

NSOpenPanel *openPanel = [[NSOpenPanel alloc] init]; 

if ([openPanel runModal] == NSOKButton) 
{ 
    NSString *selectedFileName = [openPanel filename]; 
} 

Answer 2

在10.6，有这个班的几个变化。其中一个好处是现在有一个基于块的API。

下面是如何使用的代码片段：

NSOpenPanel *panel = [[NSOpenPanel openPanel] retain]; 

// Configure your panel the way you want it 
[panel setCanChooseFiles:YES]; 
[panel setCanChooseDirectories:NO]; 
[panel setAllowsMultipleSelection:YES]; 
[panel setAllowedFileTypes:[NSArray arrayWithObject:@"txt"]]; 

[panel beginWithCompletionHandler:^(NSInteger result){ 
    if (result == NSFileHandlingPanelOKButton) { 

     for (NSURL *fileURL in [panel URLs]) { 
      // Do what you want with fileURL 
      // ... 
     } 
    } 

    [panel release]; 
}]; 

Answer 3

看到我是如何发现这个问题有用的六年后，由于没有迅速的答案，这里有一个快速的解决方案。

您会发现两个样本，一个作为独立窗口，另一个作为工作表。

雨燕3.0

func selectIcon() { 
    // create panel 
    let panel = NSOpenPanel() 

    // configure as desired 
    panel.canChooseFiles = true 
    panel.canChooseDirectories = false 
    panel.allowsMultipleSelection = false 
    panel.allowedFileTypes = ["png"] 

    // *** ONLY USE ONE OF THE FOLLOWING OPTIONS, NOT BOTH *** 

    // ********************** OPTION 1 *********************** 
    // use this if you want a selection window to display that is 
    // displayed as a separate stand alone window 
    panel.begin { [weak self] (result) in 
     guard result == NSFileHandlingPanelOKButton, panel.urls.isEmpty == false, let url = panel.urls.first else { 
      return 
     } 

     let image = NSImage.init(contentsOf: url) 
     DispatchQueue.main.async { 
      self?.iconImageView.image = image 
     } 
    } 

    // ********************** OPTION 2 ***********************   
    // use this if you want a sheet style view that displays sliding 
    // down from your apps window 
    panel.beginSheetModal(for: self.view.window!) { [weak self] (result) in 
     guard result == NSFileHandlingPanelOKButton, panel.urls.isEmpty == false, let url = panel.urls.first else { 
      return 
     } 

     let image = NSImage.init(contentsOf: url) 
     DispatchQueue.main.async { 
      self?.iconImageView.image = image 
     } 
    } 
}