Asp.net 2.0 自定义控件开发[开发一个图表(WebChart)控件(柱状图示例)](示例代码下载)
<iframe align="top" marginwidth="0" marginheight="0" src="http://www.zealware.com/46860.html" frameborder="0" width="468" scrolling="no" height="60"></iframe>
(一). 概述
本文主要演示一个比较简单的 WebChart 柱状实现, 可以一方面了解一个较完整的控件开发实例,
里面用到了复合样式及视图存储等内容.另一方面了解一下WebChart的实现原理. 在Web开发中, 最终
是用浏览器呈现各种图表, 图表控件呈现过程是 根据控件提供的属性接口接收到数据参数, 用最基本的
Html元素
| 来呈现图表. 注: 本文参考 [Asp.net 2.0高级编程] 方案, 由于本书中配套代码说明链接打不开, 所以在文章最后面可以 下载我上传的自己做得比较完整的示例代码. (二). 运行效果 1. 在浏览器中运行的柱状图
2. 主要属性 ( 可以通过修改这些属性参数修改其 外观样式和文本显示格式等信息)
主要属性用法介绍:
(三). 代码 代码比较简单, 就两个文件; 主要代码, 都包含了中文注释. 在这里对代码不作多介绍. 1. 主控件文件 SimpleGaugeBar.cs 代码
1
namespace
KingControls
2 { 3 /// <summary></summary> 4 /// Author:[ChengKing(ZhengJian)] 5 /// Blog:Http://blog.csdn.net/ChengKing 6 /// 本代码参照Asp.net2.0高级编程方案 7 /// 8 [DefaultProperty( " Value " )] 9 [ToolboxData( " {0}:SimpleGaugeBar> " )] 10 [PersistChildrenAttribute( false )] 11 public class SimpleGaugeBar:CompositeControl 12 { 13 // 在绘制输出画面时，标志是哪个TD为分界点(从这个分界点改变表格的颜色绘制) 14 private int _intDividerCell; 15 16 private TextItemStyle_textStyle; 17 18 public SimpleGaugeBar() 19 { 20 } 21 22 #region 属性 23 /// <summary></summary> 24 /// 进度条值 25 /// 26 public float Value 27 { 28 get 29 { 30 object o = ViewState[ " Value " ]; 31 if (o == null ) 32 return 0 ; 33 return float .Parse(o.ToString()); 34 } 35 set 36 { 37 this .ViewState[ " Value " ] = value; 38 if (value > Maximum) 39 { 40 this .ViewState[ " Value " ] = Maximum; 41 } 42 } 43 } 44 45 /// <summary></summary> 46 /// 全值 47 /// 48 public float Maximum 49 { 50 get 51 { 52 object o = this .ViewState[ " Maximum " ]; 53 if (o == null ) 54 { 55 return 100 ; 56 } 57 return float .Parse(o.ToString()); 58 } 59 set 60 { 61 this .ViewState[ " Maximum " ] = value; 62 } 63 } 64 65 /// <summary></summary> 66 /// 表示进度条分几段 67 /// 68 public int Segments 69 { 70 get 71 { 72 object o = this .ViewState[ " Segments " ]; 73 if (o == null ) 74 { 75 return 4 ; 76 } 77 return int .Parse(o.ToString()); 78 } 79 set 80 { 81 this .ViewState[ " Segments " ] = value; 82 if (value 1) 83{ 84this.ViewState["Segments"]=1; 85} 86} 87} 88 89///<summary></summary> 90///文本呈现格式 91/// 92publicstringFormatString 93{ 94get 95{ 96objecto=this.ViewState["FormatString"]; 97if(o==null) 98{ 99return"{0}/{1}"; 100} 101return(string)o; 102} 103set 104{ 105this.ViewState["FormatString"]=value; 106} 107} 108 109publicboolGridLines 110{ 111get 112{ 113objecto=this.ViewState["GridLines"]; 114if(o==null) 115{ 116returntrue; 117} 118return(bool)o; 119} 120set 121{ 122this.ViewState["GridLines"]=value; 123} 124} 125 126[PersistenceMode(PersistenceMode.EncodedInnerDefaultProperty)] 127[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)] 128[NotifyParentProperty(true)] 129publicTextItemStyleTextStyle 130{ 131get 132{ 133if(_textStyle==null) 134{ 135_textStyle=newTextItemStyle(); 136} 137if(IsTrackingViewState) 138{ 139((IStateManager)_textStyle).TrackViewState(); 140} 141return_textStyle; 142} 143} 144 145#endregion 146 147#region方法 148 149protectedoverridevoidRender(HtmlTextWriterwriter) 150{ 151PrepareControlForRendering(); 152base.Render(writer); 153 154//base.RenderContents(writer); 155//this.RenderContents(writer); 156//this.Render(writer); 157 158} 159 160protectedoverridevoidCreateChildControls() 161{ 162//base.CreateChildControls(); 163this.Controls.Clear(); 164CreateControlHierarchy(); 165ClearChildViewState(); 166} 167 168///<summary></summary> 169///在Web开发中，用Table/TR/TD来表示图形输出 170/// 171protectedvirtualvoidCreateControlHierarchy() 172{ 173//最外层表格 174Tableouter=newTable(); 175TableRowouterRow=newTableRow(); 176outer.Rows.Add(outerRow); 177 178TableCellrulerCell=newTableCell(); 179outerRow.Cells.Add(rulerCell); 180BuildGaugeBar(rulerCell); 181 182//根据条件增加文本显示单元格 183TableCelltextCell=newTableCell(); 184if(!TextStyle.DisplayTextAtBottom) 185{ 186outerRow.Cells.Add(textCell); 187BuildLabel(textCell); 188} 189 190this.Controls.Add(outer); 191 192if(!TextStyle.RenderInsideTable&&TextStyle.DisplayTextAtBottom) 193{ 194BuildLabel(null); 195} 196} 197 198///<summary></summary> 199///用Label来呈现文本,如:{8/10} 200/// 201/// 202voidBuildLabel(TableCelltc) 203{ 204floatbuf=GetValueToRepresent(); 205stringmsg=GetTextToRepresent(); 206 207Labellbl=newLabel(); 208if(tcisTableCell) 209{ 210tc.Controls.Add(lbl); 211} 212else 213{ 214this.Controls.Add(lbl); 215} 216lbl.Text=String.Format(msg,buf,Maximum); 217} 218 219voidBuildGaugeBar(TableCelltc) 220{ 221Tablet=newTable(); 222TableRowtr=newTableRow(); 223t.Rows.Add(tr); 224 225BuildRuler(tr); 226 227if(TextStyle.RenderInsideTable) 228{ 229BuildLabelIntoTable(t); 230} 231tc.Controls.Add(t); 232} 233 234voidBuildRuler(TableRowruler) 235{ 236floatval=GetValueToRepresent(); 237floatvalueToRepresent=100f*val/Maximum; 238intnumOfSegments=GetNumOfSegments(); 239intsegmentWidth=100/numOfSegments; 240boolfinished=false; 241for(inti=1;inumOfSegments;i++) 242{ 243if(valueToRepresenti*segmentWidth) 244{ 245if(finished) 246{ 247TableCellstillToDo=newTableCell(); 248ruler.Cells.Add(stillToDo); 249stillToDo.Width=Unit.Percentage(segmentWidth); 250} 251else 252{ 253_intDividerCell=i-1; 254TableCellcell=newTableCell(); 255ruler.Cells.Add(cell); 256cell.Width=Unit.Percentage(segmentWidth); 257cell.Height=Unit.Percentage(100); 258 259//增加子表 260Tablechild=newTable(); 261child.Width=Unit.Percentage(100); 262child.Height=Unit.Percentage(100); 263cell.Controls.Add(child); 264child.CellPadding=0; 265child.CellSpacing=0; 266TableRowchildRow=newTableRow(); 267child.Rows.Add(childRow); 268 269floatfx=(100*(valueToRepresent-segmentWidth*(i-1))/segmentWidth); 270if(valueToRepresent>(i-1)*segmentWidth) 271{ 272TableCellleft=newTableCell(); 273childRow.Cells.Add(left); 274left.Width=Unit.Percentage(fx); 275} 276TableCellright=newTableCell(); 277childRow.Cells.Add(right); 278right.Width=Unit.Percentage(100-fx); 279finished=true; 280} 281} 282else 283{ 284TableCelldone=newTableCell(); 285ruler.Cells.Add(done); 286done.Width=Unit.Percentage(segmentWidth); 287} 288} 289} 290 291///<summary></summary> 292///创建最外Table的第二行,显示文本 293/// 294/// 295voidBuildLabelIntoTable(Tablet) 296{ 297floatbuf=GetValueToRepresent(); 298intnumOfSegments=GetNumOfSegments(); 299stringmsg=GetTextToRepresent(); 300if(TextStyle.DisplayTextAtBottom) 301{ 302TableRowlabel=newTableRow(); 303t.Rows.Add(label); 304TableCelllblCell=newTableCell(); 305label.Cells.Add(lblCell); 306 307lblCell.ColumnSpan=numOfSegments; 308lblCell.Text=String.Format(msg,buf,Maximum); 309} 310} 311 312privatestringGetTextToRepresent() 313{ 314returnthis.FormatString; 315} 316 317privateintGetNumOfSegments() 318{ 319returnthis.Segments; 320} 321 322privatefloatGetValueToRepresent() 323{ 324returnthis.Value; 325} 326 327///<summary></summary> 328
分享到：
发表评论
happmaoo
最新评论
|
](http://img.e-com-net.com/image/product/736af972efc14170bbba8d7c51a725e2.jpg)
评论