错误：在Xcode

Question

我收到以下错误使用未声明的标识符NSOpenPanel的：

Use of undeclared identifier 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

NSOpenPanel不iOS可用，仅在macOS（Cocoa）。

您不能让用户浏览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，你可以让用户选择使用图像UIImagePickerController