获取工作表页边距

根据给定的工作表名称和页边距参数获取工作表的页边距。页边距可选参数：

• 例如，获取名为 Sheet1 的工作表页边距:

f := excelize.NewFile()
const sheet = "Sheet1"
var (
    marginBottom excelize.PageMarginBottom
    marginFooter excelize.PageMarginFooter
    marginHeader excelize.PageMarginHeader
    marginLeft   excelize.PageMarginLeft
    marginRight  excelize.PageMarginRight
    marginTop    excelize.PageMarginTop
)
if err := f.GetPageMargins(sheet,
    &marginBottom,
    &marginFooter,
    &marginHeader,
    &marginLeft,
    &marginRight,
    &marginTop,
); err != nil {
    fmt.Println(err)
}
fmt.Println("Defaults:")
fmt.Println("- marginBottom:", marginBottom)
fmt.Println("- marginFooter:", marginFooter)
fmt.Println("- marginHeader:", marginHeader)
fmt.Println("- marginLeft:", marginLeft)
fmt.Println("- marginRight:", marginRight)
fmt.Println("- marginTop:", marginTop)

得到输出：

Defaults:
- marginBottom: 0.75
- marginFooter: 0.3
- marginHeader: 0.3
- marginLeft: 0.7
- marginRight: 0.7
- marginTop: 0.75