如何在Roku BrightScript中获取图片？

sub GetImage()
    ' 创建位图对象
    bitmap = CreateObject("roBitmap")

    ' 图片URL
    imageUrl = "https://example.com/image.jpg"

    ' 创建URL传输对象
    urlTransfer = CreateObject("roUrlTransfer")
    urlTransfer.SetUrl(imageUrl)

    ' 发起URL请求
    if urlTransfer.AsyncGetToString() = 0 then
        ' 下载成功，将图片文件加载到位图对象中
        if urlTransfer.GetToFilesystem() = 0 then
            bitmap.FromFile(urlTransfer.GetToFilename())

            ' 在屏幕上显示图片
            screen = CreateObject("roScreen")
            screen.SetPort(CreateObject("roMessagePort"))
            screen.SetLayer(0, {bitmap})
            screen.Show()

            ' 释放资源
            screen.Close()
            bitmap.Close()
        else
            ' 下载失败
            print "Failed to download image."
        end if
    else
        ' 请求失败
        print "Failed to request image URL."
    end if
end sub