objective-c - 如何在可可中选择文件

Question

单击选择按钮后如何选择文件？当我单击选择按钮时，它应该会打开一个弹出窗口，我可以从我的硬盘中选择文件。

-(IBAction)select:(id)sender{
    NSOpenPanel* dlg =[NSOpenPanel openPanel];
    [dlg setCanChooseFiles:YES];
    [dlg setCanChooseDirectories:YES];
}

Answer 1

编辑（代码发布后）：

您实际上并没有打开面板，因此您需要以下内容：

NSInteger button = [dlg runModal];
if (button == NSFileHandlingPanelOKButton)
{
    NSURL *chosenURL = [[dlg URLs] objectAtIndex:0];
    // Do something with chosen file
}

Answer 2

编辑：NSOpenPanel只能是run modally。所以你need [YourNSOpenPanelObject runModal]。

请参阅NSOpenPanel链接。

---

使用NSOpenPanel. 下面给出了选择NSImage的示例：filteration

NSOpenPanel* openDlg = [NSOpenPanel openPanel];
//[openDlg setCanChooseFiles:YES];
//[openDlg setCanChooseDirectories:NO];
[openDlg setPrompt:@"Select"];
NSArray* imageTypes = [NSImage imageTypes];
[openDlg setAllowedFileTypes:imageTypes];
//[openDlg setAllowsOtherFileTypes:NO];
[openDlg beginWithCompletionHandler:^(NSInteger result){
 NSArray* files = [openDlg filenames];
 NSData *imgData;
 for(NSString* filePath in files)
 {
        NSURL *url = [[NSURL alloc]initFileURLWithPath:filePath];
        NSImage *img;
        if(url)
        { 
            img = [[NSImage alloc]initWithContentsOfURL:url];
            imgData = [NSData dataWithContentsOfURL:url];
            [url release];
        }
        if(img)
        {
            imgSubCategoryView.image = img; 
            [img release];
        }
        else
        {
            imgSubCategoryView.image = nil;
            NSAlert *alert = [[NSAlert alloc]init];
            [alert setMessageText:@"Application Message"];
            [alert setAlertStyle:NSInformationalAlertStyle];
            [alert setInformativeText:@"Select Only Image"];
            [alert beginSheetModalForWindow:_window
                              modalDelegate:self didEndSelector:nil contextInfo:nil];
        }
 }
}];