C# project读写操作，报如下错误System.InvalidCastException:“无法将类型为“System.__ComObject”的对象强制转换为类型“

Question

C# 新建project 使用ApplicationClass prj = new ApplicationClass(); 报如下错误System.InvalidCastException:“无法将类型为“System.__ComObject”的对象强制转换为类型“Microsoft.Office.Interop.MSProject.ApplicationClass”。

 String value0 = this.dataGridView1.Rows[rowindex].Cells[0].Value.ToString();
            String value1 = this.dataGridView1.Rows[e.RowIndex].Cells[1].Value.ToString();
            MessageBox.Show("第0列的值：{0};第一列的值：{1};第二列的值:{2}", value0 + "====" + value1);
            String FileName = "C:/temp/XXXXXA项目研制/XXXXXA项目研制.mpp";
          //  System.Diagnostics.Process.Start(FileName).WaitForExit();

            Object missing = Type.Missing;

            //Microsoft.Office.Interop.MSProject.ApplicationClass prj = new Microsoft.Office.Interop.MSProject.ApplicationClass();
            Microsoft.Office.Interop.MSProject.Application prj = new Microsoft.Office.Interop.MSProject.Application();


            string strmpp = "";
            prj.FileOpen(FileName,
            false, missing, missing, missing, missing, missing, missing, missing,
            missing, missing, PjPoolOpen.pjPoolReadWrite, missing, missing, missing, missing);
            MessageBox.Show("读取XXXXXA项目研制.mpp=01===》", strmpp);
            foreach (Project proj in prj.Projects)
            {
                foreach (Microsoft.Office.Interop.MSProject.Task task in proj.Tasks)
                {
                    if (task == null)
                        continue;
                    strmpp += "任务名称:" + task.Name + "," + task.UniqueID + ",资源名称:" + task.ResourceNames + "\r\n";//用ajax来请求的时候，此格式非json格式，会报错
                    strmpp += "任务名称:" + task.Name + "," + task.UniqueID + ",资源名称:" + task.ResourceNames;//正确方法
                }
            }

             prj.FileClose(PjSaveType.pjSave, false);//关闭
             prj.Quit(PjSaveType.pjSave);//关闭
            MessageBox.Show("读取XXXXXA项目研制.mpp==02==》", strmpp);

Answer 1

电脑上安装 Project 了么？安装的 Project 是32bit还是54bit的，在解决方案资源管理器里面删除对 Interop.MSProject 的引用，然后重新添加一次。