Go - reading (7), CopySheet Excelize API source code (the from and to the int)

Go-Excelize API源码阅读（七）—— CopySheet(from, to int)

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一、Go-Excelize简介

Excelize 是 Go 语言编写的用于操作 Office Excel 文档基础库,基于 ECMA-376,ISO/IEC 29500 国际标准.可以使用它来读取、写入由 Microsoft Excel 2007 及以上版本创建的电子表格文档.支持 XLAM / XLSM / XLSX / XLTM / XLTX 等多种文档格式,高度兼容带有样式、图片(表)、透视表、切片器等复杂组件的文档,并提供流式读写 API,用于处理包含大规模数据的工作簿.可应用于各类报表平台、云计算、边缘计算等系统.使用本类库要求使用的 Go 语言为 1.15 或更高版本.

二、CopySheet(from, to int)、

func (f *File) CopySheet(from, to int) error

该APIThe role of the function is to provide a function to copy the worksheet by giving the source worksheet and target worksheet index,This index needs to be confirmed by developers themselves.注意,Copying include tables is currently not supported、A workbook of diagrams or pictures,Only worksheet copying with cell values ​​and formulas is supported.

使用案例：

sheet_index := f.NewSheet("Sheet2")
err := f.CopySheet(1, sheet_index)

Start reading the source code directly：

func (f *File) CopySheet(from, to int) error {
    
	if from < 0 || to < 0 || from == to || f.GetSheetName(from) == "" || f.GetSheetName(to) == "" {
    
		return ErrSheetIdx
	}
	return f.copySheet(from, to)
}

This function should be givencopySheetFilter out some index errors.比如：

1. The source worksheet index is less than0Or the target worksheet index is less than0.
2. The source worksheet index is equal to the target worksheet index.
3. The source sheet does not exist or the target sheet does not exist

然后调用copySheet.

Read directly nextcopySheet的源码：

unc (f *File) copySheet(from, to int) error {
    
	fromSheet := f.GetSheetName(from)
	sheet, err := f.workSheetReader(fromSheet)
	if err != nil {
    
		return err
	}
	worksheet := deepcopy.Copy(sheet).(*xlsxWorksheet)
	toSheetID := strconv.Itoa(f.getSheetID(f.GetSheetName(to)))
	sheetXMLPath := "xl/worksheets/sheet" + toSheetID + ".xml"
	if len(worksheet.SheetViews.SheetView) > 0 {
    
		worksheet.SheetViews.SheetView[0].TabSelected = false
	}
	worksheet.Drawing = nil
	worksheet.TableParts = nil
	worksheet.PageSetUp = nil
	f.Sheet.Store(sheetXMLPath, worksheet)
	toRels := "xl/worksheets/_rels/sheet" + toSheetID + ".xml.rels"
	fromRels := "xl/worksheets/_rels/sheet" + strconv.Itoa(f.getSheetID(fromSheet)) + ".xml.rels"
	if rels, ok := f.Pkg.Load(fromRels); ok && rels != nil {
    
		f.Pkg.Store(toRels, rels.([]byte))
	}
	fromSheetXMLPath := f.sheetMap[trimSheetName(fromSheet)]
	fromSheetAttr := f.xmlAttr[fromSheetXMLPath]
	f.xmlAttr[sheetXMLPath] = fromSheetAttr
	return err
}

看第一部分：

This part is to get the source worksheet name,Then read the source worksheet.

嗯,我们继续.

worksheet := deepcopy.Copy(sheet).(*xlsxWorksheet)

这里调用了github.com/mohae/deepcopy包.

func Copy(src interface{
    }) interface{
    } {
    
	if src == nil {
    
		return nil
	}

	// Make the interface a reflect.Value
	original := reflect.ValueOf(src)

	// Make a copy of the same type as the original.
	cpy := reflect.New(original.Type()).Elem()

	// Recursively copy the original.
	copyRecursive(original, cpy)

	// Return the copy as an interface.
	return cpy.Interface()
}

CopyCreates a deep copy of the object passed to it,并在一个interface {}returns the copy in . The returned value will need to be asserted to the correct type.

Next is to get the target sheetID,And piece together the target worksheetXML路径.

如果xml文件中SheetViewcorresponding to the parameterssheetView长度大于0,这个参数是[]xlsxSheetView类型,Should be a sheet view collection.Here, when the number of views is greater than 0,就将第1view'sTabSelected 参数置为false.
TabSelectedLooking for Microsoft's documentation,There is no indication of what it is used for.Here the author guesses that it is the parameter corresponding to the box highlighted when the cell is clicked.

The next step is to initialize the three parameters of the deep copied worksheet.
然后以sheetXMLPath为键,worksheet为值,into the target worksheetMap：Sheet.

This part is processingrels文件的拷贝.

This should be the properties of the copied worksheet.

三、结语
这里是老岳,这是GoThe seventh chapter of the interpretation of language-related source code,我会不断努力,给大家带来更多类似的文章,恳请大家不吝赐教.