DAN疼之後上些基礎知識（一）

以下為一些適合新手的基礎知識，你要是說無聊，請看上一篇文章..................

接受傳直 和 快顯視窗
Response.Write("<script language=javascript>alert('調用response的方法')</script>");
        if (!IsPostBack)
        {
            string id = Request.QueryString["id"].ToString();
           

上傳圖片：
        string fullname = this.FileUpload1.FileName;
        string filename = fullname.Substring(fullname.LastIndexOf("//") + 1);
        string type = fullname.Substring(fullname.LastIndexOf(".") + 1);
        if (type == "jpg" || type == "bmp" || type == "gif")
        {
            this.FileUpload1.PostedFile.SaveAs(Server.MapPath("up") + "//" + filename);
              this.img.ImageUrl ="up"+"/"+filename ;//圖片顯示
        }
        else
            Response.Write("<script language=javascript>alert('錯了')</script>");

檢查使用者名稱是否存在：
    第一種方法：

  SqlConnection con=new SqlConnection("Server=.;database=text;uid=sa;pwd=;");
        con.Open ();
        SqlCommand com=new SqlCommand (" Select count(*) from [use] where uername='"+username.Text +"'and pwd='"+userpwd.Text +"'",con);
        int count = Convert.ToInt32(com.ExecuteScalar());
        if (count > 0)
        {
            Label1.Text = "使用者名稱已經存在";

        }
        else
        {
            Label1.Text = " 使用者名稱不存在";
        }

    第2種方法：
  
   類中的方法：
     public  int gvdababind(string strcon)
    {
        int a;
        SqlConnection con = new SqlConnection(ConfigurationManager.AppSettings["Connectionstring"]);
        con.Open();
        SqlCommand com = new SqlCommand(strcon, con);
        a = Convert .ToInt32(com.ExecuteScalar ());
        con.Close();
        return a;

    }

在後台中的代碼：
     int a =dbnew.gvdababind( " Select count(*) from [use] where uername='" + username.Text + "'and pwd='" + userpwd.Text + "'");
     if (a > 0)
        {
            Label1.Text = "使用者名稱已經存在";

        }
        else
        {
            Label1.Text = " 使用者名稱不存在";
        }

省市連動：

     類中的方法：
         public  void   ddlbind(DropDownList ddl,string str,string name,string id)
    {
        SqlConnection con=new SqlConnection (ConfigurationManager .AppSettings ["Connectionstring"]);
        con.Open ();
        SqlDataAdapter da=new SqlDataAdapter (str,con);
        DataSet ds=new DataSet ();
        da.Fill (ds);
        ddl.DataSource =ds;
        ddl.DataTextField = name;
        ddl.DataValueField = id;
        ddl.DataBind ();
        con.Close();
       // return id;

    }

      前台調用方法：
 protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
           db.ddlbind(ddlpro, "select * from provice", "proname", "proid");
    }
    protected void ddlpro_SelectedIndexChanged(object sender, EventArgs e)
    {
        db.ddlbind(ddlcity, "select * from city where proid=" + ddlpro.SelectedValue + "", "cityname", "cityid");
   }
        {

讀取xml檔案資訊：

 FileStream fs = new FileStream(Server.MapPath("XMLFile.xml"), FileMode.Open, FileAccess.Read);
        StreamReader sr = new StreamReader(fs);
        DataSet ds1 = new DataSet();
        ds1.ReadXml(sr);
        gvxml.DataSource = ds1.Tables[0];
        gvxml.DataBind();

利用返回dataset的方法 讀取dataset 中的表的內容

  方法： public  DataSet returnds()
    {
        SqlConnection con = new SqlConnection(datacon());
        con.Open();
        SqlDataAdapter da = new SqlDataAdapter("select * from [use] ", con);
        DataSet ds = new DataSet();
        da.Fill(ds);
        return ds;
        con.Close();

    }
調用：
        DataSet ds = new DataSet();
            ds = db.returnds();
            DataRowView drv = ds.Tables[0].DefaultView[0];
            lbname.Text = Convert.ToString(drv.Row["uername"]);
            lbpwd.Text = Convert.ToString(drv.Row["pwd"]);
            DataRowView drv1 = ds.Tables[0].DefaultView[1];
            lbname2.Text = Convert.ToString(drv1.Row["uername"]);
            lbpwd2.Text  = Convert.ToString(drv1.Row["pwd"]);

簡單的數字驗證碼：

        Random rd = new Random();
        lbnumber.Text  = rd.Next(1000, 10000).ToString();
數字字母組合驗證碼

    public void generatecheckcode()
    {
        int number;
        char code;
        string checkcode = string.Empty;
        Random rd = new Random();
        for (int i = 0; i < 4; i++)
        {
            number = rd.Next();
            if (number %2==0)
                code =(char )('0' +(char )(number %10));
            else
                code =(char )('A'+(char )(number %26));
            checkcode +=code .ToString ();
        }
        Label1 .Text =checkcode ;
   }

repeater 的模板編程：

在html中       <ItemTemplate >
          <%# DataBinder .Eval (Container.DataItem, "uername") %>
        </ItemTemplate>
        <AlternatingItemTemplate >
         <%#  DataBinder.Eval(Container.DataItem, "uername")%>
        </AlternatingItemTemplate>
        <FooterTemplate >頁尾</FooterTemplate>
        <HeaderTemplate >頁首</HeaderTemplate>
        <SeparatorTemplate ></SeparatorTemplate>

設為首頁 和 收藏本站代碼（注意不能用超級串連等  只能用普通漢字在html中設定）

<a href ="#" onclick ="this.style.behavior='url(#default#homepage)';this.sethomepage('http://www.sina.com')"><font color="#00cc99">設為首頁</font></a>
<a href ="#" onclick ="window.external.addFavorite('http://www.sina.com','大學生論壇');"><font color="#00cc99">收藏本站</font> </a> &nbsp;

找控制項：：

protected void dldgdd_ItemCommand(object source, DataListCommandEventArgs e)
    {
        string content = ((LinkButton)e.Item.FindControl("linkbutton1")).Text;
        Session["content"] = content;
        Response.Redirect("main.aspx?id=" + content + " ");
    }

datalist 分頁 ：

    public void dlbind()
    {
        string id = Request.QueryString["id"].ToString();
        int curpage = Convert.ToInt32(this.Label12.Text);
        PagedDataSource ps = new PagedDataSource();
        DataSet ds = null;
        ds = db.returndataset("select * from tb_return where r_fatherid='" + id + "' order by r_time desc", "tb_motif");
        ps.DataSource = ds.Tables["tb_motif"].DefaultView;
        ps.AllowPaging = true;
        ps.PageSize = 10;
        ps.CurrentPageIndex = curpage - 1;
        this.lkbtnnoback.Enabled = true;
        this.lkbtnback.Enabled = true;
        this.lkbtnn.Enabled = true;
        this.lkbtn1.Enabled = true;
        if (curpage == 1)
        {
            this.lkbtn1.Enabled = false;
            this.lkbtnnoback.Enabled = false;
        }
        if (curpage == ps.PageCount)
        {
            this.lkbtnback.Enabled = false;
            this.lkbtnn.Enabled = false;
        }
        Label15.Text = Convert.ToString(ps.PageCount);
        this.dlreturn.DataSource = ps;
        this.dlreturn.DataKeyField = "r_id";
        this.dlreturn.DataBind();

    }

    protected void lkbtn1_Click(object sender, EventArgs e)
    {
        this.Label12.Text = "1";
        this.dlbind();
    }

    protected void lkbtnnoback_Click(object sender, EventArgs e)
    {
        this.Label12.Text = Convert.ToString(Convert.ToInt32(this.Label12.Text) - 1);
        this.dlbind();
    }
    protected void lkbtnback_Click(object sender, EventArgs e)
    {
        this.Label12.Text = Convert.ToString(Convert.ToInt32(this.Label12.Text) + 1);
        this.dlbind();
    }
    protected void lkbtnn_Click(object sender, EventArgs e)
    {
        this.Label12.Text = this.Label15.Text;
        this.dlbind();
    }