go-chart go后端生成图表base64
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 | import ( "github.com/golang/freetype/truetype" <br> "github.com/wcharczuk/go-chart" <br> "github.com/wcharczuk/go-chart/drawing" )<br><br> const imgStrPrefix = "data:image/png;base64," func imgToStr(imgContent bytes.Buffer) string { return imgStrPrefix + base64.StdEncoding.EncodeToString(imgContent.Bytes()) } func loadTTF(filename string) (ttf *truetype.Font, err error) { ttfContent, err := ioutil.ReadFile(app.Cfg.Templatesdir + filename) if err != nil { return ttf, err } ttf, err = truetype.Parse(ttfContent) return } func ToBarChart(title string, data interface {}, xkey string, ykey string, ymin float64, ymax float64, isReverse bool) template.HTML { values := make([]chart.Value, 0) items, isSucc := data.([] map [string] interface {}) if !isSucc { logger.Errorf( "传入数据不符合格式" ) return "" } if isReverse { for i := len(items) - 1; i >= 0; i-- { cValueTmp := chart.Value{ Value: items[i][ykey].(float64), Label: items[i][xkey].(string), } values = append(values, cValueTmp) } } else { for _, item := range items { cValueTmp := chart.Value{ Value: item[ykey].(float64), Label: item[xkey].(string), } values = append(values, cValueTmp) } } ttf, err := loadTTF( "MSYH.TTF" ) if err != nil { logger.Warnf( "加载字体失败:%v" , err) } yrange := chart.ContinuousRange{ Min: ymin, Max: ymax, } graph := chart.BarChart{ Font: ttf, Title: title, TitleStyle: chart.Style{ Show: true, TextHorizontalAlign: chart.TextHorizontalAlignCenter, }, XAxis: chart.Style{ Show: true, StrokeWidth: 1, }, YAxis: chart.YAxis{ Name: "数量" , Style: chart.Style{ Show: true, StrokeWidth: 1, }, Range: &yrange, ValueFormatter: func (v interface {}) string { if vf, isFloat := v.(float64); isFloat { vi := int64(vf) return fmt.Sprintf( "%d" , vi) } return "" }, }, Canvas: chart.Style{ Show: true, Padding: chart.Box{ Top: 4, IsSet: true, }, FillColor: drawing.Color{120, 9, 9, 9}, }, Background: chart.Style{ Padding: chart.Box{ Top: 40, }, }, Height: 512, BarWidth: 60, Bars: values, } //buffer := bytes.NewBuffer([]byte{}) var buffer bytes.Buffer //f,err := os.Create("chart.png") err = graph.Render(chart.PNG, &buffer) if err != nil { logger.Errorf( "图表渲染错误:%v" , err) } base64str := imgToStr(buffer) return template.HTML(fmt.Sprintf( "<img src='%s' />" , base64str)) } |
【推荐】编程新体验,更懂你的AI,立即体验豆包MarsCode编程助手
【推荐】凌霞软件回馈社区,博客园 & 1Panel & Halo 联合会员上线
【推荐】抖音旗下AI助手豆包,你的智能百科全书,全免费不限次数
【推荐】博客园社区专享云产品让利特惠,阿里云新客6.5折上折
【推荐】轻量又高性能的 SSH 工具 IShell:AI 加持,快人一步