objective-c - 设置背景图片位置

Question

是否有任何符合 Mac App Store 的方式将桌面墙纸位置设置为“拉伸(stretch)以填满屏幕”？

Answer 1

This code sample from Apple很好地概述了问题以及如何在 Cocoa 中正确编码。突出的代码片段如下所示:

- (void)updateScreenOptions:(NSScreen*)screen
{
    if (screen)
    {
        NSDictionary *screenOptions = [[NSWorkspace sharedWorkspace] desktopImageOptionsForScreen:curScreen];

        // the value is an NSNumber containing an NSImageScaling (scaling factor)
        NSNumber *scalingFactor = [screenOptions objectForKey:NSWorkspaceDesktopImageScalingKey];
        [scalingPopup selectItemAtIndex:[scalingFactor integerValue]];

        // the value is an NSNumber containing a BOOL (allow clipping)
        NSNumber *allowClipping = [screenOptions objectForKey:NSWorkspaceDesktopImageAllowClippingKey];
        [[clippingCheckbox cell] setState:[allowClipping boolValue]];

        // the value is an NSColor (fill color)
        NSColor *fillColorValue = [screenOptions objectForKey:NSWorkspaceDesktopImageFillColorKey];
        if (fillColorValue)
            [fillColor setColor:fillColorValue];
    }
}

如 some of the answer errata 中所述，此处解决您问题的正确方法调用似乎是 [screenOptions setObject:scalingFactor forKey:NSWorkspaceDesktopImageScalingKey] 和 [[NSWorkspace sharedWorkspace] setDesktopImageURL:imageURL forScreen:curScreen options:screenOptions error:&error ]，它应该提供所需的功能。

我坦白承认this was a collaborative effort ，但似乎我们已经错误地找到了正确的解决方案。

(关于 NSImageScaling 枚举和 NSWorkspace 的附加信息，其中包含正确的缩放键。)