NSSavePanel文件路径

Question

只有在处理文本文件时才使用NSSavePanel。如果我有一个要导出的图像，我使用NSOpenPanel，这样用户就可以选择一个目录，并且不会在沙箱文件路径限制中被捕获。不过，这一次，我想使用NSSavePanel来让用户保存一个图像文件(bmp、gif、jpeg、jp2、png)。

- (void)exportfile {    
    NSString *documentFolderPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
    NSSavePanel *panel = [NSSavePanel savePanel];

    [panel setMessage:@"Please select a path where to save checkboard as an image."]; // Message inside modal window
    if ([self fileExists:destinationpath]) {
        [panel setDirectoryURL:[NSURL fileURLWithPath:destinationpath]];
    } else {
        [panel setDirectoryURL:[NSURL fileURLWithPath:documentFolderPath]];
    }

    //[panel setAllowedFileTypes:[[NSArray alloc] initWithObjects:@"bmp",@"gif",@"jpg",@"jp2",@"png",nil]];
    [panel setAllowsOtherFileTypes:YES];
    [panel setExtensionHidden:YES];
    [panel setCanCreateDirectories:YES];
    [panel setNameFieldStringValue:filename];
    [panel setTitle:@"Saving checkboard..."]; // Window title
    [panel setAccessoryView:accessoryView1];

    NSInteger result = [panel runModal];
    NSError *error = nil;

    if (result == NSOKButton) {     
        ////////////////////////////////////////////
        NSString *path0 = [[panel URL] path];
        NSMutableString *path1 = [[NSMutableString alloc] initWithString:path0];
        if (formatIndex1 == 0) { // formatIndex1 is the index of NSPopMenu
            [path1 appendString:@".bmp"];
        }
        else if (formatIndex1 == 1) {
            [path1 appendString:@".gif"];
        }
        else if (formatIndex1 == 2) {
            [path1 appendString:@".jpg"];
        }
        else if (formatIndex1 == 3) {
            [path1 appendString:@".jp2"];
        }
        else if (formatIndex1 == 4) {
            [path1 appendString:@".png"];
        }
        [self exportfile2:path1]; // <<<<<<<<<<<<<<< Immediate goal
        ////////////////////////////////////////////

        if (error) {
            [NSApp presentError:error];
        }
    }
}

这个NSSavePanel有一个AccessoryView控件，允许用户选择带有NSPopupMenu的图形格式。其指数为formatIndex1。我知道，如果应用程序是沙箱的话，代码就会失败。这是因为用户选择的确切路径是path0，上面的代码在到达exportfile2之前给它添加了一个文件扩展名。那么，如何获得具有文件扩展名的确切路径。如果“隐藏扩展名”关闭，预览会自动追加文件扩展名。然而，预览并不会不导出图像。

谢谢你的帮助。

Answer 1

试着这样做：-

- (void)exportfile {    
    NSSavePanel *panel = [NSSavePanel savePanel];
NSString *fileName=nil;

        if (formatIndex1 == 0) { // formatIndex1 is the index of NSPopMenu
        fileName=@"untitle.bmp"
        }
        else if (formatIndex1 == 1) {
        fileName=@"untitle.gif"
        }
        else if (formatIndex1 == 2) {
          fileName=@"untitle.jpg"
        }

[panel setMessage:@"Please select a path where to save checkboard as an image."]; // Message inside modal window
    [panel setAllowsOtherFileTypes:YES];
    [panel setExtensionHidden:YES];
    [panel setCanCreateDirectories:YES];
    [panel setNameFieldStringValue:filename];
    [panel setTitle:@"Saving checkboard..."]; // Window title
    [panel setAccessoryView:accessoryView1];

    NSInteger result = [panel runModal];
    NSError *error = nil;

    if (result == NSOKButton) {     
        ////////////////////////////////////////////
        NSString *path0 = [[panel URL] path];


        [self exportfile2:path0]; // <<<<<<<<<<<<<<< Immediate goal
        ////////////////////////////////////////////

        if (error) {
            [NSApp presentError:error];
        }
    }
}