经过大量的调试后,我已经缩小了为什么我的dbContext
更新不起作用。
我有一个在Page_Load
上运行的脚本,它将根据查询字符串category_Id
填充表单,这是我表的主键。
protected void Page_Load(object sender, EventArgs e)
{
// Populate Edit Fields
if (Request.QueryString["categoryId"] != null)
{
CategoryDAL categoryDAL = new CategoryDAL();
RecipeCategory myCategory = new RecipeCategory();
try
{
addDiv.Attributes["class"] = "hidden";
editDiv.Attributes["class"] = "display";
int categoryToGet = Convert.ToInt32(Request.QueryString["categoryId"]);
myCategory = categoryDAL.GetCategory(categoryToGet);
tbEditCategoryName.Text = myCategory.Category_Name;
tbEditCategoryDescription.Text = myCategory.Description;
ddlEditCategoryGroupList.SelectedValue = Convert.ToString(myCategory.CatGroup_Id);
ddlEditCategoryGroupList.DataBind();
}
catch(Exception ex)
{
updateStatus.Attributes["class"] = "alert alert-info alert-dismissable fade in";
updateStatus.Visible = true;
lblStatus.Text = "Could not get Category Info, please try again.";
}
}
这是我单击edit_Button时运行的脚本,它应该更新数据库中的行并重定向到viewCategories页面。
protected void btnEditCategory_Click(object sender, EventArgs e)
{
if (Request.QueryString["categoryId"] != null)
{
CategoryDAL categoryDAL = new CategoryDAL();
RecipeCategory myCategory = new RecipeCategory();
try
{
int categoryToEdit = Convert.ToInt32(Request.QueryString["categoryId"]);
myCategory.Category_Name = tbEditCategoryName.Text;
myCategory.Description = tbEditCategoryDescription.Text;
myCategory.CatGroup_Id = Convert.ToInt32(ddlEditCategoryGroupList.SelectedValue);
try
{
bool editStatus = categoryDAL.EditCategory(categoryToEdit, myCategory);
if (editStatus)
{
HttpContext.Current.Session["editStatus"] = "Successful";
Response.Redirect("~/Admin/ManageCategories.aspx");
}
else
{
lblEditStatus.Text = "Unable to update category, please try again";
lblEditStatus.CssClass = "alert-danger";
}
}
catch (Exception ex)
{
lblEditStatus.Text = Convert.ToString(ex);
lblEditStatus.CssClass = "alert-danger";
}
}
catch (Exception ex)
{
updateStatus.Attributes["class"] = "alert alert-info alert-dismissable fade in";
updateStatus.Visible = true;
lblStatus.Text = "Invalid categoryId.";
}
}
else
{
updateStatus.Attributes["class"] = "alert alert-info alert-dismissable fade in";
updateStatus.Visible = true;
lblStatus.Text = "Nothing to update.";
}
}
这是在我的DALayer中,其中包含与类别有关的功能。
public bool EditCategory(int categoryToEdit, RecipeCategory newCategoryInfo)
{
RecipeXchangeDBContext dbContext = new RecipeXchangeDBContext();
RecipeCategory myCategory = new RecipeCategory();
bool status = false;
myCategory = (from c in dbContext.RecipeCategories
where c.Category_Id == categoryToEdit
select c).First();
myCategory.Category_Name = newCategoryInfo.Category_Name;
myCategory.Description = newCategoryInfo.Description;
myCategory.CatGroup_Id = newCategoryInfo.CatGroup_Id;
try
{
if (dbContext.SaveChanges() == 1)
status = true;
else
status = false;
}
catch (InvalidOperationException ex)
{
status = false;
}
return status;
}
出于某种原因,每当我尝试使用预填充表单更新行时,代码将始终从dbContext.SaveChanges()
返回0,并且不会更新数据库中的行。
注意:如果我没有填充表单,它会正常工作。
答案 0 :(得分:1)
Page_Load
不仅在第一次加载页面时运行,而是在每次加载页面时运行,包括用户提交表单时。结果是您在保存之前覆盖了用户的输入。
在这种情况下,由于您使用常规浏览器导航转到特定类别页面,因此您只需检查Page.IsPostBack
中的Page_Load
,而不是在这种情况下设置任何内容。