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[求助]查询结果显示的问题
<DIV>实现了属性查询,可是想把属性结果在一个表里显示出来.思路是这样的:我用了一个datatable,先把查询结果的要显示属性存在里面,然后通过datagridview显示(其数据源是datatable).代码如下,由于初学不知道错在哪了,还请各位多多执教:<BR><BR> IQueryFilter pQueryFilter=new QueryFilterClass();<BR> IFeatureLayer pFeatureLayer;<BR> pQueryFilter.WhereClause = textBoxWhereClause.Text;<BR> pFeatureLayer = GetLayerByName(comboBoxLayers.SelectedItem.ToString()) as IFeatureLayer;<BR> pFeatureSelection = pFeatureLayer as IFeatureSelection;<BR> int iSelectedFeaturesCount = pFeatureSelection.SelectionSet.Count;<BR> pFeatureSelection.SelectFeatures(pQueryFilter, selectmethod, false);//执行查询<BR> <BR> //如果本次查询后,查询的结果数目没有改变,则认为本次查询没有产生新的结果<BR> if (pFeatureSelection.SelectionSet.Count == 0)<BR> {<BR> MessageBox.Show("没有符合本次查询条件的结果!");<BR> return;<BR> }<BR> DataTable presource = new DataTable();<BR> <BR> DataColumn pname1 = new DataColumn("name1", typeof(string));<BR> DataColumn pname2 = new DataColumn("name2", typeof(string));<BR> DataColumn pname3 = new DataColumn("name3", typeof(string));<BR> <BR> presource.Columns.Add(pname1);<BR> presource.Columns.Add(pname2);<BR> presource.Columns.Add(pname3);<BR> IEnumFeature pIEnumFeature;<BR> IFeature pIFeature;<BR> pIEnumFeature = pFeatureSelection as IEnumFeature;<BR> pIFeature = pIEnumFeature.Next();<BR> while (pIFeature != null)<BR> {<BR> string name1 = pIFeature.get_Value(0).ToString();<BR> string name2 = pIFeature.get_Value(2).ToString();<BR> string name3 = pIFeature.get_Value(3).ToString();<BR> DataRow newrow = presource.NewRow();<BR> MessageBox.Show("name1");<BR> newrow["name1"] = name1;<BR> newrow["name2"] = name2;<BR> newrow["name3"] = name3;<BR> presource.Rows.Add(newrow);<BR> pIFeature = pIEnumFeature.Next();<BR> }<BR> DataGridViewColumn dcolumn1 = new DataGridViewColumn();<BR> DataGridViewColumn dcolumn2 = new DataGridViewColumn();<BR> DataGridViewColumn dcolumn3 = new DataGridViewColumn();<BR> dataGridView1.Columns.Add(dcolumn1);<BR> dataGridView1.Columns.Add(dcolumn2);<BR> dataGridView1.Columns.Add(dcolumn3);<BR> dataGridView1.DataSource = presource;<BR><BR>编译通过,但是运行该模块是,提示"<a href="http://www.2mysite.net/blogview.asp?logID=1223;cateID=1" target="_blank" ><FONT size=3><FONT color=#c60a00>未将</FONT><FONT color=#0000ff>对象</FONT><FONT color=#c60a00>引用设置为</FONT><FONT color=#0000ff>对象的实例</FONT></FONT></A>",什么原因?</DIV>
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1楼#
发布于:2009-04-30 21:18
<P>pIEnumFeature.reset()</P>
<P>while(pIEnumFeature.movenext)</P> <P>{</P> <P>pIFeature = pIEnumFeature.current</P> <P>....</P> <P>}</P> <P>不知道行不行</P> |
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