我想用Go試試圖形庫。我發現了下面的例子:轉至:undefined class
package main
import (
"image"
"image/color"
"image/png"
"log"
"os"
)
func main() {
width, height := 512, 512
canvas := NewCanvas(image.Rect(0, 0, width, height))
canvas.DrawGradient()
// Draw a series of lines from the top left corner to the bottom of the image
for x := 0; x < width; x += 8 {
canvas.DrawLine(color.RGBA{0, 0, 0, 255},
Vector{0.0, 0.0},
Vector{float64(x), float64(height)})
}
outFilename := "lines.png"
outFile, err := os.Create(outFilename)
if err != nil {
log.Fatal(err)
}
defer outFile.Close()
log.Print("Saving image to: ", outFilename)
png.Encode(outFile, canvas)
}
但是,當建設似乎有些類缺失。
D:\go\work>go build draw.go
# command-line-arguments
.\draw.go:13: undefined: NewCanvas
.\draw.go:19: undefined: Vector
.\draw.go:20: undefined: Vector
我的環境在HelloWorld示例中運行正常,但是在導入圖像庫時似乎缺少某些東西。任何幫助開始一個新手?
從哪裏找到這個例子?我從某個網頁假設......沒有解釋爲了使用'NewCanvas'函數和'Vector'類型你需要安裝和導入哪些軟件包? – ain