手把手教你如何扩展GridView之自带CheckBox

      我们在使用GridView的时候,很多时候需要使用CheckBox列,比如批量删除,批量审批,但是每每都需要记住繁琐的实现方法。多麻烦呀!再次给GridView做个手术,让它自己就能产生CheckBox岂不爽死了。以后您就有权利忘记怎么实现CheckBox列了。哈哈,作咱们这行的,就要学的慢慢退化,什么事情都记着,累也累死了。
      下面谈谈我这实现的思路:
      因为GridView是基于模板的,Columns也不能在后台添加,所以排除通过添加Column来实现,而采用在GridView创建行的时候动态创建表单元格,在表头行上添加一个全选CheckBox,数据行上添加选择框,点击全选,通过向页面注册的脚本来实现全选。
   下面就看看关键的代码:
    为了增加灵活性,添加了一个属性,控制是否显示CheckBox列  

   //是否显示全选
        [
      Description(
"显示全选列"),
      Category(
"扩展"),
        DefaultValue(
false)
      ]
        
public virtual bool ShowCheckAll
        
{
            
get
            
{
                
object obj2 = this.ViewState["ShowCheckAll"];
                
if (obj2 != null)
                
{
                    
return (bool)obj2;
                }

                
return false;

            }

            
set
            
{
                
bool aShowCheckAll = this.ShowCheckAll;
                
if (value != aShowCheckAll)
                
{
                    
this.ViewState["ShowCheckAll"= value;
                    
if (base.Initialized)
                    
{
                        
base.RequiresDataBinding = true;
                    }

                }

            }

        }

用于控制选择列是添加到表的左端还是右端的属性

 public enum CheckColumnAlign
    
{
        Left, Right
    }


   
//是否显示全选
        [
      Description(
"全选列的位置"),
      Category(
"扩展"),
      DefaultValue(CheckColumnAlign.Left)
      ]
        
public virtual CheckColumnAlign CheckColumnAlign
        
{
            
get
            
{
                
object obj2 = this.ViewState["CheckColumnAlign"];
                
if (obj2 != null)
                
{
                    
return (CheckColumnAlign)obj2;
                }

                
return CheckColumnAlign.Left;
            }

            
set
            
{
                CheckColumnAlign aCheckColumnAlign 
= this.CheckColumnAlign;
                
if (value != aCheckColumnAlign)
                
{
                    
this.ViewState["CheckColumnAlign"= value;
                    
if (base.Initialized)
                    
{
                        
base.RequiresDataBinding = true;
                    }

                }

            }

        }

在页面加载的时候,注册全选脚本

 StringBuilder sb = new StringBuilder();
            sb.Append(
" <script type=\"text/javascript\">");
            sb.Append(
"function CheckAll(oCheckbox)");
            sb.Append(
"{");
            sb.Append(
"var GridView2 = document.getElementById(\"" + this.ClientID + "\");");
            sb.Append(
" for(i = 1;i < GridView2.rows.length; i++)");
            sb.Append(
"{");
            sb.Append(
"var inputArray = GridView2.rows[i].getElementsByTagName(\"INPUT\");");
            sb.Append(
"for(var j=0;j<inputArray.length;j++)");
            sb.Append(
"{ if(inputArray[j].type=='checkbox')");
            sb.Append(
"{if(inputArray[j].id.indexOf('ItemCheckBox',0)>-1){inputArray[j].checked =oCheckbox.checked; }}  }");
            sb.Append(
"}");
            sb.Append(
" }");
            sb.Append(
"</script>");
            ScriptManager.RegisterClientScriptBlock(
thisthis.GetType(), "CheckFun", sb.ToString(), false);

在GridView的RowCreate事件中,添加如下代码,用于创建CheckBox列

   if (ShowCheckAll)
                
{
                    GridViewRow row 
= e.Row;
                    
if (row.RowType == DataControlRowType.Header)
                    
{
                        TableCell cell 
= new TableCell();
                        cell.Wrap 
= Wrap;
                        cell.Width 
= Unit.Pixel(50);
                        cell.Text 
= " <input id='Checkbox2' type='checkbox' onclick='CheckAll(this)'/><label>全选</label>";
                        
if (CheckColumnAlign == CheckColumnAlign.Left)
                        
{
                            row.Cells.AddAt(
0, cell);
                        }

                        
else
                        
{
                            
int index = row.Cells.Count;
                            row.Cells.AddAt(index, cell);
                        }

                    }

                    
else if (row.RowType == DataControlRowType.DataRow)
                    
{
                        TableCell cell 
= new TableCell();
                        cell.Wrap 
= Wrap;
                        CheckBox cb 
= new CheckBox();
                        cell.Width 
= Unit.Pixel(50);
                        cb.ID 
= "ItemCheckBox";
                        cell.Controls.Add(cb);
                        
if (CheckColumnAlign == CheckColumnAlign.Left)
                        
{
                            row.Cells.AddAt(
0, cell);
                        }

                        
else
                        
{
                            
int index = row.Cells.Count;
                            row.Cells.AddAt(index, cell);
                        }

                    }

                }

用于记录CheckBox的ID的属性

 public string CheckBoxID
        
{
            
get
            
{
                
return "ItemCheckBox";
            }

        }

使用的时候,只需要设置扩展GridView的ShowCheckAll=True,设置CheckColumnAlign为Left,CheckBox列在最左边,Right在最右面,注意因为没有添加Columns,所以Columns并没有因为因为添加了CheckBox列而变化,在Column的索引中,CheckBox列不在计算范围。
在扩展的GridView的OnRowDataBound事件中,就可以通过
CheckBox cb = e.Row.FindControl(gridView.CheckBoxID) as CheckBox;
if(cb!=null)

    if(cb.Checked)
   {
        //...
   }
}
来获取是否已经选中此行。
上篇文章:手把手教你如何扩展GridView之自动排序篇
 

posted @ 2007-06-07 20:48 Robin Zhang 阅读(...) 评论(...) 编辑 收藏