Question

我在工作表上有多个图表的excel文件。我从excel获取图表并将其保存到图片中。

我的代码：

workSheet = workBook.Sheets[1] as Excel._Worksheet;
Excel.ChartObjects chartObjects =(Excel.ChartObjects)workSheet.ChartObjects(Type.Missing);
int chartCount = chartObjects.Count;
for (int j = 1; j <= chartCount; j++)
{
     Excel.ChartObject chart = (Excel.ChartObject)chartObjects.Item(j);
     path = Path.Combine(Application.StartupPath, @"Img\" + chart.Chart.Name + ".bmp");
     chart.Chart.Export(path, "BMP", true);
}

但只导出空白图片。

请帮帮我

Answer 1

在调用.Export时导出屏幕上至少部分不可见的图表似乎会产生空白图像。

尝试添加一行代码以在导出之前激活要导出的图表（我遇到了同样的问题，这对我有用）：

Excel.ChartObject chart = (Excel.ChartObject)chartObjects.Item(j);
path = Path.Combine(Application.StartupPath, @"Img\" + chart.Chart.Name + ".bmp");
chart.Activate(); //New line
chart.Chart.Export(path, "BMP", true);

Answer 2

我遇到了同样的问题并尝试了.Activate技巧，但这并没有帮助。基于图表需要至少部分可见的注释，我在.Export行之前尝试了一个简单的延迟循环：

For i = 1 to N
  DoEvents
Next i

这解决了这个问题。通过一些实验，我发现N> = 3工作，但如果N = 1或2，或者如果我取出循环，代码返回输出空白图片。我不理解它，但我想我会传递观察结果。

Answer 3

谢谢@小夫您花了将近一天的时间为我的小型Python项目寻找解决方案时，您在导出之前在图表激活方面的信息确实对我有所帮助。干杯。

对于正在寻找Python脚本版本以将Excel图表导出为GIF或PNG格式的任何人，下面的代码对我有用：

# Python function to export an Excel chart to a GIF image format
# Ref: https://stackoverflow.com/questions/11110752/export-charts-from-excel-as-images-using-python
def ChartExport(cwd, fileName):
    app = win32.Dispatch('Excel.Application')
    workbook_file_name = cwd + fileName
    workbook = app.Workbooks.Open(Filename=workbook_file_name)

    # WARNING: The following line will cause the script to discard any unsaved changes in your workbook
    app.DisplayAlerts = False

    i = 1   # There are multiple charts on the worksheet. So using a number suffix to add the output gif filename
    for sheet in workbook.Worksheets:
        for chartObject in sheet.ChartObjects():
            #print('i = ', i, ' -- ', sheet.Name + ':' + chartObject.Name)
            chartObject.Activate()  # This line was added after finding exporting problem with 2nd and 3rd charts. Thanks Xiaofu Ref: https://stackoverflow.com/questions/15911536/excel-chart-export-not-working
            chartObject.Chart.Export(cwd + '\\chart' + str(i) + '.gif')  # Export chart to a gif file format
            i += 1

    workbook.Close(SaveChanges=False, Filename=workbook_file_name)
    return

Excel.Chart.Export无效

3 个答案: