objective-c - NSOpenPanel setAllowedFileTypes

Question

我有一个 NSOpenPanel。但我想让它只能选择 PDF 文件。我正在寻找类似的东西:

// NOT WORKING 
NSOpenPanel *panel;

panel = [NSOpenPanel openPanel];
[panel setFloatingPanel:YES];
[panel setCanChooseDirectories:YES];
[panel setCanChooseFiles:YES];
[panel setAllowsMultipleSelection:YES];
[panel setAllowedFileTypes:[NSArray arrayWithObject:@"pdf"]];
int i = [panel runModalForTypes:nil];
if(i == NSOKButton){
    return [panel filenames];
}

我希望有人有解决方案。

Answer 1

我注意到几件事.. 将 setCanChooseDirectories 更改为 NO。启用后，这表示文件夹是有效输入。这很可能不是您想要的功能。对于区分大小写的系统，您可能还想将允许的文件类型更改为 [NSArray arrayWithObject:@"pdf", @"PDF", nil]。 runModalForTypes 应该是文件类型数组。将您的代码更改为如下所示:

// WORKING :)
NSOpenPanel *panel;
NSArray* fileTypes = [NSArray arrayWithObjects:@"pdf", @"PDF", nil];
panel = [NSOpenPanel openPanel];
[panel setFloatingPanel:YES];
[panel setCanChooseDirectories:NO];
[panel setCanChooseFiles:YES];
[panel setAllowsMultipleSelection:YES];
[panel setAllowedFileTypes:fileTypes];
int i = [panel runModal];
if(i == NSOKButton){
    return [panel URLs];
}

swift 4.2:

let fileTypes = ["jpg", "png", "jpeg"]
let panel = NSOpenPanel()
panel.canChooseFiles = true
panel.canChooseDirectories = false
panel.allowsMultipleSelection = false
panel.allowedFileTypes = fileTypes
panel.beginSheetModal(for: window) { (result) in
    if result.rawValue == NSApplication.ModalResponse.OK.rawValue {
         // Do something with the result.
         let selectedFolder = panel.urls[0]
         print(selectedFolder)
    }
}