用户代码未处理 System.NullReferenceExceptionMessage="未将对象引用设置到对象的实例。" [问题点数:20分]

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【C#】错误“System.NullReferenceException:未将对象引用设置对象实例“解析
错误原因分析   首先,你要知道,在.net里面所有操作的变量都是<em>对象</em>。   一般的标示符,如int,string,char等等,最后都会转换为System命名空间下面的类名(如Int32,String,Char等等),当然类<em>实例</em>化的就更不用说了。<em>对象</em>就必然存在若干的属性和方法。你要操作一个<em>对象</em>,也必然是操作它的属性或者方法。   “<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>”,也就是说你要调用<em>对象</em><em>实例</em>里
c#System.NullReferenceException:“未将对象引用设置对象实例。”
using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Threading.Tasks; using System.W...
未将对象引用设置对象实例"">C#中出现"System.NullReferenceException: 未将对象引用设置对象实例"
任何引用类型你不要轻易相信他是非 null 的,在调用其成员(包括方法、属性等)之前,要问下自己这个<em>对象</em>非空吗? 一般利用if(xxx!=null){}即可解决
用户代码未处理NullReferenceException未将对象引用设置对象实例
[img=https://img-bbs.csdn.net/upload/201510/31/1446295247_964577.png][/img][img=https://img-bbs.csdn.net/upload/201510/31/1446295376_846019.png][/img]
用户代码未处理NullReferenceException 未将对象引用设置对象实例
string mystr = WebConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString; rn<em>用户</em><em>代码</em><em>未处理</em>NullReferenceExceptionrn<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>rnrn求大神解决rnrn下面是全部<em>代码</em>rnrnusing System;rnusing System.Collections.Generic;rnusing System.Linq;rnusing System.Web;rnusing System.Data.SqlClient;rnusing System.Data;rnusing System.Web.Configuration;rnrn/// rn///commonclass 的摘要说明rn/// rnpublic class CommonClassrnrn public CommonClass()rn rn //rn //TODO: 在此处添加构造函数逻辑rn //rn rn public SqlConnection GetConnection()rn rn string mystr = WebConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;rn SqlConnection myconn = new SqlConnection(mystr);rn return myconn;rn rn public string MessageBox(string TxtMessage, string Url)rn rn string str;rn str = " ";rn return str;rn rn public Boolean ExecSQL(string sqlStr)rn rn SqlConnection myconn = GetConnection();rn myconn.Open();rn SqlCommand mycmd = new SqlCommand(sqlStr, myconn);rn tryrn rn mycmd.ExecuteNonQuery();rn myconn.Close();rn rn catchrn rn myconn.Close();rn return false;rn rn return true;rn rn public DataSet GetDataSet(string sqlstr, string TableName)rn rn SqlConnection myconn = GetConnection();rn myconn.Open();rn SqlDataAdapter adapt = new SqlDataAdapter(sqlstr, myconn);rn DataSet ds = new DataSet();rn adapt.Fill(ds, TableName);rn myconn.Close();rn return ds;rn rn public int checkLogin(string loginName, string loginPwd)rn rn SqlConnection myconn = GetConnection();rn SqlCommand mycmd = new SqlCommand("select count(*) from tb_user where Name = @loginName and PassWord = @loginPwd",myconn);rnrn mycmd.Parameters.Add(new SqlParameter("@loginName",SqlDbType.VarChar,20));rn mycmd.Parameters["@loginName"].Value = loginName;rn mycmd.Parameters.Add(new SqlParameter("@loginPwd", SqlDbType.VarChar, 20));rn mycmd.Parameters["@loginPwd"].Value = loginPwd;rn myconn.Close();rnrn int i = Convert.ToInt32(mycmd.ExecuteScalar());rn mycmd.Dispose();rn mycmd.Clone();rn return i;rn rn public string RandomNum(int n)rn rn string strchar = "0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W,X,Y,Z,a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t,u,v,w,x,y,z";rnrn string[] VcArray = strchar.Split(',');rn string VNum = "";rnrn int temp = -1;rn Random rand = new Random();rn for (int i = 1; i < n + 1; i++)rn rn if (temp != -1)rn rn rand = new Random(i * temp * unchecked((int)DateTime.Now.Ticks));rn rn int t = rand.Next(61);rn if (temp != -1 && temp == t)rn rn return RandomNum(n);rn rn temp = t;rn VNum += VcArray[t];rn rn return VNum;rn rn public SqlDataReader ExecReader(string sqlstr)rn rn SqlConnection myconn = GetConnection();rn myconn.Open();rn SqlCommand cmd = new SqlCommand(sqlstr, myconn);rn SqlDataReader sdr = cmd.ExecuteReader();rn myconn.Close();rn return sdr;rn rn
未将对象引用设置对象实例未处理NullreferenceException
光标在if(comboclass.selectedvalue.tostring() != "0")rn这里停住了,需要引用什么?
未处理 NullReferenceException 未将对象引用设置对象实例
原因: 调用了a.shuxing1 = bianliang1; 但是呢,这个a其实是一个null 所以就出错了 解决办法(确保a不为null): 先ClassA a = new ClassA(); 再a.shuxing1 = bianliang1;  ...
未处理NullReferenceException--未将对象引用设置对象实例
介绍: 今天小编在做机房重构的时候改了下D层一个类的名字:将 QueryDAL改成了LoginQueryDAL,然后出现了以下错误。 于是小编找到了以下这篇博客https://www.cnblogs.com/KeenLeung/archive/2013/06/23/3150578.html,尝试了其中的办法后还是没有解决。接着小编找来了小伙伴,小伙伴火眼金睛,一下就找到了错误
未将对象引用设置对象">用户代码未处理 System.NullReferenceException Message="未将对象引用设置对象
using System;rnusing System.Data;rnusing System.Configuration;rnusing System.Collections;rnusing System.Web;rnusing System.Web.Security;rnusing System.Web.UI;rnusing System.Web.UI.WebControls;rnusing System.Web.UI.WebControls.WebParts;rnusing System.Web.UI.HtmlControls;rnrnpublic partial class forumadmindetail : System.Web.UI.Pagernrn protected void Page_Load(object sender, EventArgs e)rn rnrn rn protected void FormView1_ItemDeleted(object sender, FormViewDeletedEventArgs e)rn rn Response.Redirect("~forumadmin.aspx");rn rn protected void DataList1_EditCommand(object source, DataListCommandEventArgs e)rn rn DataList1.EditItemIndex = e.Item.ItemIndex;rn DataList1.DataBind();rn rn protected void DataList1_CancelCommand(object source, DataListCommandEventArgs e)rn rn DataList1.EditItemIndex = -1;rn DataList1.DataBind();rn rn protected void DataList1_DeleteCommand(object source, DataListCommandEventArgs e)rn rn AccessDataSource2.DeleteParameters["re_id"].DefaultValue = Convert.ToString(DataList1.DataKeys[e.Item.ItemIndex]);rn AccessDataSource2.Delete();rn DataList1.EditItemIndex = -1;rn DataList1.DataBind();rn rn protected void DataList1_UpdateCommand(object source, DataListCommandEventArgs e)rn rn TextBox TB1 = (TextBox)e.Item.FindControl("TextBox1");rn AccessDataSource2.UpdateParameters["re_subjext"].DefaultValue = TB1.Text;rn TextBox TB2 = (TextBox)e.Item.FindControl("TextBox2");rn AccessDataSource2.UpdateParameters["re_content"].DefaultValue = TB2.Text;rn TextBox TB3 = (TextBox)e.Item.FindControl("TextBox3");rn AccessDataSource2.UpdateParameters["re_name"].DefaultValue = TB3.Text;rn AccessDataSource2.UpdateParameters["re_id"].DefaultValue = Convert.ToString(DataList1.DataKeys[e.Item.ItemIndex]);rn AccessDataSource2.Update();rn DataList1.EditItemIndex = -1;rn DataList1.DataBind();rn rnrnrn每次运行到这句话:AccessDataSource2.UpdateParameters["re_id"].DefaultValue = Convert.ToString(DataList1.DataKeys[e.Item.ItemIndex]); 就会出现: <em>用户</em><em>代码</em><em>未处理</em> System.NullReferenceException Message="<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>rnrn请各位多多指教,本人是新手,多谢!
未将对象引用设置对象实例
起因:文件中的类都不能进行设计,因此未能为该文件显示设计器。设计器检查出文件中有以下类: FormMain --- 未能加载基类“WinForm.Win.FormsBase.FormMainBase”。请确保已引用该程序集并已生成所有项目我用了一个小时找百度。这个的解决方法,就是将你删除过的一个窗体,再添加上就好了。。。。有点生气的。。然后出现了:<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>的问题这个问题的解决方...
未将对象引用设置对象实例
<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>。 rn说明: 执行当前 Web 请求期间,出现<em>未处理</em>的异常。请检查堆栈跟踪信息,以了解有关该错误以及<em>代码</em>中导致错误的出处的详细信息。 rnrn异常详细信息: System.NullReferenceException: <em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>。rnrn源错误: rnrnrn行 91: rn行 92: Users user = new Users();rn行 93: if(user.IsTest(Session["userID"].ToString().Trim(),Convert.ToInt32(ddlPaper.SelectedValue)))rn行 94: rn行 95: lblMessage.Text = "您已经考试过了,不能再考试!"; rn rnrn源文件: f:\Downloads\MyOnLineExam\MyOnLineExam\Web\StudentIndex.aspx.cs 行: 93 rnrn堆栈跟踪: rnrnrn[NullReferenceException: <em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>。]rn Web_StudentIndex.Button1_Click(Object sender, EventArgs e) in f:\Downloads\MyOnLineExam\MyOnLineExam\Web\StudentIndex.aspx.cs:93rn System.Web.UI.WebControls.Button.OnClick(EventArgs e) +78rn System.Web.UI.WebControls.Button.RaisePostBackEvent(String eventArgument) +100rn System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +10rn System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +13rn System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +36rn System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2863rnrn rn求助,这个问题怎么解决。
未将对象引用设置对象实例
我是新手 不知道哪出问题了 我看了 有NULL出现 但是不知道怎么改啊 rn 弹出一个对话框 显示"<em>用户</em><em>代码</em><em>未处理</em>NullferenceExceotion"rn具体<em>代码</em>如下rnusing System;rnusing System.Data;rnusing System.Configuration;rnusing System.Web;rnusing System.Web.Security;rnusing System.Web.UI;rnusing System.Web.UI.WebControls;rnusing System.Web.UI.WebControls.WebParts;rnusing System.Web.UI.HtmlControls;rnusing System.Web.Configuration;rnusing System.Data.SqlClient;rnrnpublic partial class _Default : System.Web.UI.Page rnrn protected void Page_Load(object sender, EventArgs e)rn rn string connectionString = WebConfigurationManager.ConnectionStrings["Test"].ConnectionString;rn SqlConnection con = new SqlConnection(connectionString);rn string sql = "select * from '操作员信息'";rn SqlCommand cmd = new SqlCommand(sql, con);rn 显示.Text = sql;rn rn protected void Button1_Click(object sender, EventArgs e)rn rnrn rnrn
未将对象引用设置对象实例"">"未将对象引用设置对象实例"
一开始就出现“<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>”。后来不知道怎么的又好了,出结果了,可是现在又出现这个问题了。 CrystalReportViewer1.ReportSource = (ReportDocument)Session["CrRpt"];出错误的就是这句。
未将对象引用设置对象实例??
<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>。 rn说明: 执行当前 Web 请求期间,出现<em>未处理</em>的异常。请检查堆栈跟踪信息,以了解有关该错误以及<em>代码</em>中导致错误的出处的详细信息。 rnrn异常详细信息: System.NullReferenceException: <em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>。rnrn源错误: rnrnrn行 24: using (SqlConnection connection = new SqlConnection(ConfigurationManager.ConnectionStrings["CarManage"].ConnectionString))rn行 25: rn行 26: using (SqlCommand command = new SqlCommand("insert into UserMessage(UserName,UPassword,UCode,UName,USex,UBir,UMZ,USFZ,UPhone,UBuMen,UAddress,UPerMissions) values('" + this.TextBox1.Text + "','" + this.TextBox2.Text + "','" + this.TextBox4.Text + "','" + this.TextBox9.Text + "'," + this.RadioButtonList1.SelectedValue + ",'" + birthday.Value + "','" + DropDownListNation.Items[this.DropDownListNation.SelectedIndex].Text + "','" + this.TextBox5.Text + "','" + this.TextBox6.Text + "','" + this.bumen.Items[this.DropDownListNation.SelectedIndex].Text + "','" + this.TextBox7.Text + "','" + RadioButtonList2.SelectedItem.Text + "')"))rn行 27: rn行 28: connection.Open();//打开数据库连接rn rnrn源文件: f:\CarManage\Register.aspx.cs 行: 26 rnrn//源文件rnpublic partial class Register : System.Web.UI.Pagernrn protected void Page_Load(object sender, EventArgs e)rn rnrn rn protected void Button1_Click(object sender, EventArgs e)rn rn using (SqlConnection connection = new SqlConnectionrnrn(ConfigurationManager.ConnectionStrings["CarManage"].ConnectionString))rn rn using (SqlCommand command = new SqlCommand("insert into UserMessagernrn(UserName,UPassword,UCode,UName,USex,UBir,UMZ,USFZ,UPhone,UBuMen,UAddress,UPerMissiornrnns) values('" + this.TextBox1.Text + "','" + this.TextBox2.Text + "','" + rnrnthis.TextBox4.Text + "','" + this.TextBox9.Text + "'," + rnrnthis.RadioButtonList1.SelectedValue + ",'" + birthday.Value + "','" + rnrnDropDownListNation.Items[this.DropDownListNation.SelectedIndex].Text + "','" + rnrnthis.TextBox5.Text + "','" + this.TextBox6.Text + "','" + this.bumen.Itemsrnrn[this.DropDownListNation.SelectedIndex].Text + "','" + this.TextBox7.Text + "','" + rnrnRadioButtonList2.SelectedItem.Text + "')"))rn rn connection.Open();rn command.Connection = connection;rn int result = (int)command.ExecuteNonQuery();rn if (result != 0)rn rn JScript.AlertAndRedirect("登录成功!", "Login.aspx"); rnrn rn elsern rn JScript.AlertAndRedirect("登录失败,请重新输入您的<em>用户</em>名和密码!", "#");rn rn rn rn rnrn[color=#FF0000]rn 乞求高手前来赐教[/color]
未将对象引用设置对象实例
提交数据成功后跳转到另一个页面时就会出现“<em>未将</em><em><em>对象</em>引用</em>到<em>设置</em><em>对象</em>的<em>实例</em>”这种黄页,但数据提交是成功了的,刷新一下页面又显示正常了,请问下这是什么原因啊,先谢过了
未将对象引用设置对象实例..
我知道这个很简单 ,但是..但是 我百度了好久都不会- -~ rn求解-,-rn private string connectionstring = ConfigurationManager.ConnectionStrings["connection"].ConnectionString;rn protected void Page_Load(object sender, EventArgs e)rn rn if (!IsPostBack)rn rn show();rn rn rn protected void show()rn rn string m_id = Request["m_id"].ToString();rn SqlConnection con = new SqlConnection(connectionstring);rn con.Open();rn string selectmessage = "select * from message where m_id='" + m_id + "'";rn SqlCommand cmd = new SqlCommand(selectmessage, con);rn SqlDataReader dr = cmd.ExecuteReader();rn if (dr.Read())rn rn this.Tbname.Text = dr["m_name"].ToString();rn this.Tbsubject.Text = dr["m_subject"].ToString();rn this.Tbcontent.Text = dr["m_content"].ToString();rn this.TBreplay.Text = dr["m_replay"].ToString();rn rn dr.Close();rn con.Close();rn
未将对象引用设置对象实例???
private void 音乐试听ToolStripMenuItem_Click(object sender, EventArgs e)rn rn Frm_YinYue x = new Frm_YinYue();rn x.ShowDialog();//就是这里出现问题的rn rn rn 下面的这是Frm_YinYuernrn public partial class Frm_YinYue : Formrn rn //申明一个字符串数组来储存歌曲的地址rn private string[] urlname = new string[2000];rn WMPLib.IWMPMediaCollection mediacollection;rn WMPLib.IWMPMedia media;rnrn //添加单个地址上的mp3文件rnrn private void Addfile(string path)rn rn string songname = path.Substring(path.LastIndexOf('\\') + 1);rn songname = songname.Substring(0, songname.Length - 4);rn mediacollection = axWindowsMediaPlayer1.mediaCollection;rn media = mediacollection.add(path);rn axWindowsMediaPlayer1.currentPlaylist.appendItem(media);rn mediacollection.remove(media, false);rn listBox1.Items.Add(songname);rn urlname[listBox1.Items.Count - 1] = path;rn rnrn public Frm_YinYue()rn rn InitializeComponent();rn rnrn private void 打开文件ToolStripMenuItem_Click(object sender, EventArgs e)rn rn tryrn rn DialogResult result = openFileDialog1.ShowDialog();rn if (result == DialogResult.OK)rn rnrn //songname为歌曲名rn string songname = openFileDialog1.FileName.Substring(openFileDialog1.FileName.LastIndexOf("\\") + 1);rn songname = songname.Substring(0, songname.Length - 1);rn //刷新当前播放的列表rn axWindowsMediaPlayer1.currentPlaylist.clear();rn //同步刷新listBoxrn listBox1.Items.Clear();rn axWindowsMediaPlayer1.URL = openFileDialog1.FileName;rn this.Text = songname + "--Windows Media Player";rn listBox1.Items.Add(songname);rn urlname[listBox1.Items.Count - 1] = openFileDialog1.FileName;rn //播放当前打开的曲目rn axWindowsMediaPlayer1.Ctlcontrols.play();rnrn rnrn rn catch (Exception error)rn rn MessageBox.Show(error.Message.ToString());rn rn rnrn private void 删除文件ToolStripMenuItem_Click(object sender, EventArgs e)rn rn //listBox1.Items.Clear();//这里的是清除listbox中的所有内容rn listBox1.Items.Remove(listBox1.SelectedItem.ToString ());//此处是删除listbox中选中的项rn // this.axWindowsMediaPlayer1.Ctlcontrols.stop();//停止播放rn rn rnrn private void 关闭ToolStripMenuItem_Click(object sender, EventArgs e)rn rn listBox1.Items.Clear();rn rnrn private void 添加单个文件ToolStripMenuItem_Click(object sender, EventArgs e)rn rn tryrn rn DialogResult result = openFileDialog1.ShowDialog();rn if (result == DialogResult.OK)rn rn this.Addfile(openFileDialog1.FileName);rn urlname[listBox1.Items.Count - 1] = openFileDialog1.FileName;rn //播放当前打开的曲目rn axWindowsMediaPlayer1.Ctlcontrols.play();rnrn rn rn catch (Exception error)rn rn MessageBox.Show(error.Message.ToString());rn rn rn private void 播放rlToolStripMenuItem_Click(object sender, EventArgs e)rn rn if (listBox1.Items.Count > 0)rn rn if (this.listBox1.SelectedItems.Count > 0)rn rn if (axWindowsMediaPlayer1.playState == WMPLib.WMPPlayState.wmppsPaused)rn rn axWindowsMediaPlayer1.Ctlcontrols.play();rn rn elsern axWindowsMediaPlayer1.Ctlcontrols.pause();rnrn rn rn elsern rn MessageBox.Show("请选择歌曲!", "信息提示", MessageBoxButtons.OK, MessageBoxIcon.Information);rn rn rnrn private void 上一曲ToolStripMenuItem_Click(object sender, EventArgs e)rn rn tryrn rn if (listBox1.SelectedIndex >= 0)rn listBox1.SelectedIndex = listBox1.SelectedIndex - 1;rn if (listBox1.SelectedIndex < 0)rn rn listBox1.SelectedIndex = listBox1.Items.Count - 1;rn rnrn //这里的<em>代码</em>是:当选择了上一曲后,就立即播放上一曲rnrn WMPLib.IWMPMedia nowmedia = axWindowsMediaPlayer1.currentPlaylist.get_Item(listBox1.SelectedIndex);rn axWindowsMediaPlayer1.Ctlcontrols.playItem(nowmedia);rnrn rn catch (Exception) ;rn rnrn private void 下一曲ToolStripMenuItem_Click(object sender, EventArgs e)rn rn axWindowsMediaPlayer1.Ctlcontrols.next();//这个是系统自带的下一曲方法rnrn tryrn rn if (listBox1.SelectedIndex >= 0)rn listBox1.SelectedIndex = listBox1.SelectedIndex +1;rn if (listBox1.SelectedIndex < 0)rn rn listBox1.SelectedIndex = listBox1.Items.Count +1;rn rnrn //这里的<em>代码</em>是:当选择了上一曲后,就立即播放上一曲rn WMPLib.IWMPMedia nowmedia = axWindowsMediaPlayer1.currentPlaylist.get_Item(listBox1.SelectedIndex);rn axWindowsMediaPlayer1.Ctlcontrols.playItem(nowmedia);rnrn rn catch (Exception) ;rn rnrn rnrn rnrn private void listBox1_DoubleClick(object sender, EventArgs e)rn rn if (listBox1.SelectedIndex > -1)rn rn WMPLib.IWMPMedia nowmedia = axWindowsMediaPlayer1.currentPlaylist.get_Item(listBox1.SelectedIndex);rn axWindowsMediaPlayer1.Ctlcontrols.playItem(nowmedia);rnrn rn rnrn rnrn private void 打开文件ToolStripMenuItem2_Click(object sender, EventArgs e)rn rn 打开文件ToolStripMenuItem_Click(sender, e);rn rnrn private void 上一曲ToolStripMenuItem1_Click(object sender, EventArgs e)rn rn 上一曲ToolStripMenuItem_Click(sender, e);rn rnrn private void 下一曲ToolStripMenuItem1_Click(object sender, EventArgs e)rn rn 下一曲ToolStripMenuItem_Click(sender, e);rn rnrn private void 停止ToolStripMenuItem_Click(object sender, EventArgs e)rn rn axWindowsMediaPlayer1.Ctlcontrols.stop();rn rnrn private void 退出ToolStripMenuItem_Click(object sender, EventArgs e)rn rn DialogResult dr = MessageBox.Show("您确定要退出吗?", "系统提示", MessageBoxButtons.YesNo, MessageBoxIcon.Information);rn if (dr == DialogResult.Yes)rn this.Close();rn elsern return;rn rnrn private void toolStripMenuItem3_Click(object sender, EventArgs e)rn rn 添加单个文件ToolStripMenuItem_Click(sender, e);rn rnrn private void toolStripMenuItem2_Click(object sender, EventArgs e)rn rn listBox1.Items.Remove(listBox1.SelectedItem.ToString());rn rn rn
未将对象引用设置对象实例
[code=VB.NET]rn FrmNAreaMassInjunction.LabArea.Text = "区域:" & areas(IntArea).AreaName & " 聚集车辆列表"rn With Frm.AsfgrdVeh_Rectrn .Rows = UBound(areas(IntArea).VehNo) + 1 '[color=#FF0000]——〉在这句出现<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>错误![/color]rn .set_ColAlignment(0, VSFlex7U.AlignmentSettings.flexAlignLeftCenter)rn For i = 1 To .Rowsrn Tryrn .set_Cell(VSFlex7U.CellPropertySettings.flexcpText, i, 0, i, 0, areas(IntArea).VehNo(i - 1))rn .set_Cell(VSFlex7U.CellPropertySettings.flexcpText, i, 1, i, 1, areas(IntArea).StrIp(i - 1))rn Catch ex As Exceptionrnrn End Tryrn Nextrn End Withrn Frm.Show()rn[/code]rnrn程序运行到 Frm.Show() 窗体显示出来后,将窗体关闭,程序再运行下去就出现<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>错误 ! rn
未将对象引用设置对象实例??
做搜索时,单击搜索出现<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>.什么意思?大家帮忙!rnDim conn As SqlConnectionrn Function GetSearchview() As DataViewrn Dim strvalue As String = Trim("txtSearchstring.text")rn If strvalue <> "" Thenrn strvalue = "%" & strvalue & "%"rn End Ifrn conn = New SqlConnection ("server=wiz02;uid=exam;pwd=exam;database=bookshop")rn Dim mycommand As SqlCommandrnrn Select Case SelCategory.SelectedItem.Valuern Case "title"rn mycommand = New SqlCommand("SearchByTitle", conn)rn mycommand.Parameters.Add(New SqlParameter("@title", SqlDbType.VarChar, 50))rn mycommand.Parameters("@title").Value = strvaluern Case "author"rn mycommand = New SqlCommand("SearchByAuthor", conn)rn mycommand.Parameters.Add(New SqlParameter("@author", SqlDbType.VarChar, 40))rn mycommand.Parameters("@author").Value = strvaluern Case "publisher"rn mycommand = New SqlCommand("SearchByPublisher", conn)rn mycommand.Parameters.Add(New SqlParameter("@publisher", SqlDbType.VarChar, 30))rn mycommand.Parameters("@publisher").Value = strvaluern End Selectrn mycommand.CommandType = CommandType.StoredProcedurern Dim ds As DataSetrn ds = New DataSet()rn Dim adapter As New SqlDataAdapter(mycommand)rn adapter.Fill(ds, "bookstore")rn If ds.Tables("bookstore").Rows.Count > 0 Thenrn Return (ds.Tables("bookstore").DefaultView)rn Elsern Return (Nothing)rn End Ifrn End Functionrn rn Sub data_bind(ByVal dview As DataView, ByVal bindobject As Object)rn bindobject.datasource = dviewrn bindobject.databind()rn End Subrnrn Private Sub btnsearch_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnsearch.Clickrn Dim dview As DataView = GetSearchview()rn If dview.Count > 0 Thenrn lblResult.Text = "共找到" & dview.Count & "条记录."rn Elsern lblResult.Text = "对不起,没有找到符合条件的记录!"rn End Ifrn Session("Gridview") = dviewrn BookStore.CurrentPageIndex = 0rn data_bind(Session("Gridview"), BookStore)rn End Sub
未将对象引用设置对象实例!
<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em> !rnrn是怎么回事!rnrn
未将对象引用设置对象实例?
Private Sub mm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Loadrn Dim sqlstr As Stringrn Dim ds1 As DataSetrn sqlstr = "select distinct gcmc from textinfo"rn ds1 = GetDataFromDb2(sqlstr, "textinfo")rn ComboBox1.DataSource = ds1.Tables("textinfo")rn ComboBox1.DisplayMember = "gcmc"rn Me.MaximizeBox = Falsern End Sub rnrnrnrnrnPrivate Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChangedrn Dim sqlstr As Stringrn Dim ds As DataSetrn Dim temptext As Stringrn Dim bind As New BindingSourcernrn temptext = ComboBox1.Textrn sqlstr = "select * from textinfo where gcmc='" & temptext & "'"rn ds = GetDataFromDb2(sqlstr, "textinfo")rn bind.DataSource = dsrn bind.DataMember = "textinfo"rn DataGridView1.DataSource = bindrnrn DataGridView1.Columns("gcmc").HeaderCell.Value = "工程名称"rnrn End Subrnrnrn运行提示: DataGridView1.Columns("gcmc").HeaderCell.Value = "工程名称" 这个语句,<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>?rn该怎么处理呀?
未将对象引用设置对象实例 ???
<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>。 rn说明: 执行当前 Web 请求期间,出现<em>未处理</em>的异常。请检查堆栈跟踪信息,以了解有关该错误以及<em>代码</em>中导致错误的出处的详细信息。 rnrn异常详细信息: System.NullReferenceException: <em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>。rnrn源错误: rnrnrn行 21: private void Page_Load(object sender, System.EventArgs e)rn行 22: rn行 23: string id=Request["Tname"].ToString();rn行 24: string pass=Request["Tpass"].ToString();rn行 25: if(id=="a"&&pass=="a")rn rn
未将对象引用设置对象实例????????????
<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>。 rn说明: 执行当前 Web 请求期间,出现<em>未处理</em>的异常。请检查堆栈跟踪信息,以了解有关该错误以及<em>代码</em>中导致错误的出处的详细信息。 rnrn异常详细信息: System.NullReferenceException: <em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>。rnrn源错误: rnrnrn行 82:Db AddDb=new Db();rn行 83:string Sql1;rn行 84:Sql1="update Site_Info set SiteName='"+tbxSiteName.Text+"',SiteManager='"+tbxSiteManage.Text+"',"+rn行 85:"SiteUrl='"+tbxSitePwd.Text+"',ManagePwd='"+tbxSitePwd.Text+"' where Id="+Int32.Parse(lblSiteId.Text);rn行 86: if (AddDb.ExeSql(Sql1)==1)rn rnrnrn行 85:显示红色,什么原因啊
未将对象引用设置对象实例?????
源错误: rnrn执行当前 Web 请求期间生成了<em>未处理</em>的异常。可以使用下面的异常堆栈跟踪信息确定有关异常原因和发生位置的信息。 rnrn堆栈跟踪: rnrnrn[NullReferenceException: <em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>。]rn MyCharu.实验1.DataGrid1_UpdateCommand(Object source, DataGridCommandEventArgs e) +101rn System.Web.UI.WebControls.DataGrid.OnUpdateCommand(DataGridCommandEventArgs e) +109rn System.Web.UI.WebControls.DataGrid.OnBubbleEvent(Object source, EventArgs e) +507rn System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +26rn System.Web.UI.WebControls.DataGridItem.OnBubbleEvent(Object source, EventArgs e) +106rn System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +26rn System.Web.UI.WebControls.Button.OnCommand(CommandEventArgs e) +121rn System.Web.UI.WebControls.Button.System.Web.UI.IPostBackEventHandler.RaisePostBackEvent(String eventArgument) +115rn System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +18rn System.Web.UI.Page.RaisePostBackEvent(NameValueCollection postData) +33rn System.Web.UI.Page.ProcessRequestMain() +1277rnrn rnrnrn--------------------------------------------------------------------------------rn版本信息: Microsoft .NET Framework 版本:1.1.4322.573; ASP.NET 版本:1.1.4322.573 rnrnrn---------------------------rn程序:rnprivate void DataGrid1_ItemCreated(object sender, System.Web.UI.WebControls.DataGridItemEventArgs e)rn rn ListItemType lit=e.Item.ItemType;rn if (lit==ListItemType.EditItem)rn rn rn System.Web.UI.WebControls.Image Image2;rn Image2=(System.Web.UI.WebControls.Image)e.Item.FindControl("Image2");rn rn DataRowView drv=(DataRowView)e.Item.DataItem;rn if (drv!=null)rn rn rn Image2.ImageUrl=drv["相片"].ToString();rn rn rn rn rn rn rnprivate void DataGrid1_UpdateCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)rn rn string strConn="server=xw;uid=sa;pwd=sa;database=Car";rn sqlConnection1.ConnectionString=strConn;rn rn string cmd="UPDATE 驾驶员情况表 set"; rn cmd+=" 相片='"+((System.Web.UI.HtmlControls.HtmlInputFile)e.Item.Cells[0].FindControl("File1")).Value+"'";rn cmd+="where ID="+DataGrid1.DataKeys[(int)e.Item.ItemIndex].ToString();rn rn SqlCommand sqlCommand1=new SqlCommand(cmd,sqlConnection1);rn sqlConnection1.Open();rn sqlCommand1.ExecuteNonQuery();rn sqlConnection1.Close();rn sqlDataAdapter1.Fill(aaDataSet11);rn DataGrid1.EditItemIndex=-1;rn DataGrid1.DataBind();rnrnrn rn
未将对象引用设置对象实例
private void dl_blank_ItemDataBound(object sender, System.Web.UI.WebControls.DataListItemEventArgs e)rnrn PlaceHolder ph=new PlaceHolder();rn ph=(PlaceHolder)e.Item.FindControl("PlaceHolder2");rnrn TextBox tba=new TextBox();rn tba.Columns=100;rn tba.BorderStyle=BorderStyle.None;rn tba.TextMode=TextBoxMode.SingleLine;rn ph.Controls.Add(tba);   //此行报错:<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>rnrn我这段<em>代码</em>错在什么地方啊?rn为什么总是提示:“行 103: ph.Controls.Add(tba);”<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>呢?rn
未将对象引用设置对象实例.
[code=csharp]rn private void toolStripButton1_Click(object sender, EventArgs e)rn rnrn if (this.toolStripTextBox1.Text.Equals(""))rn rn return;rn rnrnrn // Linq模糊查询 rn IEnumerable enumerableList = this.dataGridView1.Rows.Cast();rn List list = (from item in enumerableListrn where item.Cells[0].Value.ToString().IndexOf(this.toolStripTextBox1.Text) >= 0rn select item).ToList();rnrn // 恢复之前行的背景颜色为默认的白色背景 rn this.dataGridView1.Rows[beforeMatchedRowIndex].DefaultCellStyle.BackColor = System.Drawing.Color.White;rnrn if (list.Count > 0)rn rn // 查找匹配行高亮显示 rn int matchedRowIndex = list[0].Index;rn this.dataGridView1.Rows[matchedRowIndex].DefaultCellStyle.BackColor = System.Drawing.Color.Yellow;rn this.beforeMatchedRowIndex = matchedRowIndex;rn rn rn [/code]rn运行查询后系统提示 item.Cells[0].Value.ToString().IndexOf(this.toolStripTextBox1.Text) >= 0 <em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>.rn网上说要进行赋值,请问怎么修改,谢谢指点!
未将对象引用设置对象实例
声明了以下方法用于上传图片.程序开始调试是正常的,可以上传图片,后来我在控件外面加了一个UpdatePanel ,再点Upload上传时,程序执行到下面红颜色一行<em>代码</em>是出现:"<em>未将</em><em><em>对象</em>引用</em><em>设置</em>到<em>对象</em>的<em>实例</em>"错误提示!请教如何解决!!??rn protected void UploadImg_Click(object sender, EventArgs e)rn rn string fullname = File1.FileName.ToString();rn string fn = DateTime.Now.ToString("yyyyMMddHHmmss") + fullname;rn string typ2 = fullname.Substring(fullname.LastIndexOf(".") + 1);rn [color=#FF0000]string size = File1.PostedFile.ContentLength.ToString();[/color]rn if (typ2 == "jpg" || typ2 == "gif")rn rn File1.SaveAs(Server.MapPath("img") + "\\" + fn);rn Response.Write(" ");rn this.ImgUrl.Text = "img/" + fn;rn this.shipPhoto.ImageUrl = "img/" + fn;rn rn elsern rn Response.Write(" ");rn rn
人脸识别demo下载
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我们是很有底线的