如何在ASP.NET的Crystal Report中替换图片并适配原有宽度？

你的核心问题是获取了旧图片的尺寸但未实际应用到新图片上，且代码中使用了未定义的w和h变量。以下是修正后的完整实现，确保新图片继承旧图片的宽高：

private void ReplaceHeaderAndFooter(ReportDocument report)
{
    var clientDoc = report.ReportClientDocument.ReportDefController;

    const string HeaderPath = "Reports\\Images\\headerSIS.png";
    const string FooterPath = "Reports\\Images\\footerSIS.png";
    string newHeaderImagePath = Path.GetFullPath(HeaderPath);
    string newFooterImagePath = Path.GetFullPath(FooterPath);

    // 获取报表页眉区域
    var headerSection = clientDoc.ReportDefinition.ReportHeaderArea.Sections[0];
    int oldWidth = 0;
    int oldHeight = 0;
    string oldHeaderPictureName = string.Empty;

    // 定位页眉中的旧图片并保存其尺寸和名称
    if (headerSection.ReportObjects.Count > 0)
    {
        for (int i = 0; i < headerSection.ReportObjects.Count; i++)
        {
            var reportObj = headerSection.ReportObjects[i];
            if (reportObj.Kind == CrystalDecisions.ReportAppServer.ReportDefModel.CrReportObjectKindEnum.crReportObjectKindPicture)
            {
                oldHeaderPictureName = reportObj.Name;
                oldWidth = reportObj.Width;
                oldHeight = reportObj.Height;
                break; // 假设页眉只有一张图片，找到后退出循环
            }
        }
    }

    // 删除旧图片并导入新图片
    if (!string.IsNullOrEmpty(oldHeaderPictureName))
    {
        clientDoc.ReportObjectController.Remove(headerSection.ReportObjects[oldHeaderPictureName]);
        // 导入新图片到页眉的(0,0)位置
        clientDoc.ReportObjectController.ImportPicture(newHeaderImagePath, headerSection, 0, 0);
    }

    // 调整新图片的尺寸为旧图片的尺寸
    if (headerSection.ReportObjects.Count > 0)
    {
        for (int i = 0; i < headerSection.ReportObjects.Count; i++)
        {
            var reportObj = headerSection.ReportObjects[i];
            if (reportObj.Kind == CrystalDecisions.ReportAppServer.ReportDefModel.CrReportObjectKindEnum.crReportObjectKindPicture)
            {
                var newPictureObj = (CrystalDecisions.ReportAppServer.ReportDefModel.PictureObject)reportObj;
                // 直接应用旧图片的宽高（Crystal Report使用缇(Twip)作为单位，无需转换）
                newPictureObj.Width = oldWidth;
                newPictureObj.Height = oldHeight;
                // 提交修改到报表定义
                clientDoc.ReportObjectController.Modify(newPictureObj);
                break;
            }
        }
    }

    // 以下是页脚图片的替换逻辑，和页眉同理
    var footerSection = clientDoc.ReportDefinition.ReportFooterArea.Sections[0];
    int oldFooterWidth = 0;
    int oldFooterHeight = 0;
    string oldFooterPictureName = string.Empty;

    if (footerSection.ReportObjects.Count > 0)
    {
        for (int i = 0; i < footerSection.ReportObjects.Count; i++)
        {
            var reportObj = footerSection.ReportObjects[i];
            if (reportObj.Kind == CrystalDecisions.ReportAppServer.ReportDefModel.CrReportObjectKindEnum.crReportObjectKindPicture)
            {
                oldFooterPictureName = reportObj.Name;
                oldFooterWidth = reportObj.Width;
                oldFooterHeight = reportObj.Height;
                break;
            }
        }
    }

    if (!string.IsNullOrEmpty(oldFooterPictureName))
    {
        clientDoc.ReportObjectController.Remove(footerSection.ReportObjects[oldFooterPictureName]);
        clientDoc.ReportObjectController.ImportPicture(newFooterImagePath, footerSection, 0, 0);
    }

    if (footerSection.ReportObjects.Count > 0)
    {
        for (int i = 0; i < footerSection.ReportObjects.Count; i++)
        {
            var reportObj = footerSection.ReportObjects[i];
            if (reportObj.Kind == CrystalDecisions.ReportAppServer.ReportDefModel.CrReportObjectKindEnum.crReportObjectKindPicture)
            {
                var newPictureObj = (CrystalDecisions.ReportAppServer.ReportDefModel.PictureObject)reportObj;
                newPictureObj.Width = oldFooterWidth;
                newPictureObj.Height = oldFooterHeight;
                clientDoc.ReportObjectController.Modify(newPictureObj);
                break;
            }
        }
    }
}

关键修正点： #

1. 使用旧图片的尺寸变量：将原来未定义的w和h替换为之前保存的oldWidth和oldHeight，确保新图片和旧图片尺寸完全一致。
2. 明确对象类型转换：将ISCRPictureObject转换为PictureObject，确保可以正确访问和修改尺寸属性。
3. 提交修改：调用ReportObjectController.Modify()方法，确保尺寸修改被应用到报表定义中。
4. 优化循环逻辑：找到目标图片后立即退出循环，避免不必要的遍历。

额外注意事项： #

• Crystal Report的尺寸单位是缇(Twip)，1缇=1/1440英寸，无需手动转换，直接复用旧图片的数值即可。
• 如果报表页眉/页脚存在多张图片，需要调整逻辑（比如通过名称匹配）来定位目标图片，本代码假设每个区域只有一张图片。

内容的提问来源于stack exchange，提问作者Ahmad_Lutfi