错误：在Xcode中使用未声明的标识符NSOpenPanel

Question

我收到以下错误：

  

使用未声明的标识符NSOpenPanel

NSOpenPanel *panel = [NSOpenPanel openPanel];
[panel setCanChooseFiles:NO];
[panel setCanChooseDirectories:YES];
[panel setAllowsMultipleSelection:YES]; // yes if more than one dir is allowed 
NSInteger clicked = [panel runModal];
if (clicked == NSFileHandlingPanelOKButton) 
{
    for (NSURL *url in [panel URLs]) 
    {
        // do something with the url here.
    }
}

Answer 1

仅在NSOpenPanel（iOS）下macOS才提供

Cocoa。

您无法让用户浏览iOS下的文件系统。您可以使用Apples公共API浏览某些文件类型。例如，您可以让用户使用UIImagePickerController

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