如何创建一个 ImageView 作为拖放？

Question

我想知道如何拖放 ImageView，我将某个文件拖到 ImageView 中，它会渲染一个动作。

我知道我可以在脚本编辑器中使用下面的代码并将其另存为然后应用程序可以将文件拖入其中并执行操作，但想要知道如何在 ImageView 中完成它。

提前致谢！

on open myItems
    repeat with one_item in myItems
        ---Blablabla        
    end repeat
end open

Answer 1

一个 NSImageView 的父级 class 是 NSControl，所以像任何其他控件一样，它有一个 target/action 你可以指定，对于示例：

use AppleScript version "2.4" -- Yosemite (10.10) or later
use framework "Foundation"
use scripting additions

property mainWindow : missing value

on run -- Script Editor example
    my performSelectorOnMainThread:"doWindowStuff" withObject:(missing value) waitUntilDone:true
end run

on doWindowStuff() -- window stuff needs to be done on the main thread
    try
        set my mainWindow to makeWindow out of {{0, 0}, {400, 200}} given title:"Drag an image:"
        set imageView to makeImageView out of {{100, 50}, {200, 100}}
        mainWindow's contentView's addSubview:imageView
        mainWindow's makeKeyAndOrderFront:me
    on error errmess
        display alert "Error" message errmess
    end try
end doWindowStuff

to makeWindow out of frame given title:title : "" -- make and return a window
    tell (current application's NSWindow's alloc()'s initWithContentRect:frame styleMask:7 backing:2 defer:yes) -- styleMask of 7 includes title, close and minimize buttons
        if first item of frame is {0, 0} then tell it to |center|()
        its setAutorecalculatesKeyViewLoop:true
        its setTitle:title
        return it
    end tell
end makeWindow

to makeImageView out of frame -- make and return an image view
    tell (current application's NSImageView's alloc()'s initWithFrame:frame)
        its setTarget:me
        its setAction:"imageDragged:"
        its setEditable:true
        its setImageScaling:(current application's NSImageScaleProportionallyUpOrDown)
        return it
    end tell
end makeImageView

on imageDragged:sender
    activate me
    display dialog "An image was dragged into the image view."
end imageDragged:

要执行诸如获取放置图像的文件路径之类的操作，NSImageView 需要被子classed。对于 Xcode 项目，为子 class 添加一个新的 .applescript 文件，并在 IB 的 Identity Inspector 中将其设置为您的 imageView 的 class:

script MyImageView -- NSImageView subclass

    property parent : class "NSImageView"
    property imagePath : missing value

    on draggingEntered:sender
        # additional stuff as desired
        return current application's NSDragOperationCopy
    end draggingEntered:

    on performDragOperation:sender
        set pasteboard to sender's draggingPasteboard()
        set theOptions to {NSPasteboardURLReadingFileURLsOnlyKey:1}
        set imageURLs to pasteboard's readObjectsForClasses:{current application's |NSURL|} options:theOptions
        set draggedURL to first item of (imageURLs as list)
        set my imagePath to draggedURL as text
        return true -- data accepted
    end performDragOperation:

end script

您还应该在 AppDelegate 的设置中为您的 imageView 注册可接受的拖动类型：

imageView's registerForDraggedTypes:{"public.image"}

当您将某些内容拖到视图中时，文件路径将在 imageView 的 imagePath 属性中可用。有关详细信息，请参阅 Apple Drag and Drop Programming Topics。

如何创建一个 ImageView 作为拖放？

How to create an ImageView as drag and drop?

applescript-objc