一个通用的DataGridTableStyle的做法
2024-07-21 02:23:09
供稿：网友
一个通用的datagridtablestyle的做法
哈，这两天都喜欢写“通用”的东西。
这个类，可以实现自适应列宽、只读、时分显示、事件、任意位置加列、单击单元格背景色设置等等，操作简便。只是时间关系（明天要出去一趟），今天没办法完善。仅供参考，你可以加入别的东西。以下只列代码了，不清楚的自己试用查资料就行了。
public class tablestyle
private m_datagridtablestyle as datagridtablestyle
private m_datagrid as datagrid
private m_datatable as datatable
'//添加事件处理，在此只考虑datagridtextboxcolumn双击事件
public delegate sub clickeventhandler(byval sender as object, byval e as system.eventargs)
public event gridtextboxdoubleclickevent as clickeventhandler
public sub gridtextbox_doubleclick(byval sender as object, byval e as system.eventargs)
raiseevent gridtextboxdoubleclickevent(sender, e)
end sub
'//设置datagrid
public property [datagrid]() as datagrid
get
return m_datagrid
end get
set(byval value as datagrid)
m_datagrid = value
end set
end property
'//返回模板
public readonly property [datagridtablestyle]() as datagridtablestyle
get
return m_datagridtablestyle
end get
end property
'//初始化
public sub initialize()
'//判断mdatagrid数据源类型
'//如果绑定的是dataset或dataviewmanager或没有绑定任何数据源，则退出,
if typeof m_datagrid.datasource is system.data.dataset orelse _
typeof m_datagrid.datasource is system.data.dataviewmanager orelse _
m_datagrid.datasource is nothing then exit sub
'//以下分别考虑两种数据源，一是dataview,一是datatable
if typeof m_datagrid.datasource is system.data.dataview then
m_datatable = ctype(m_datagrid.datasource, dataview).table
else
m_datatable = ctype(m_datagrid.datasource, datatable)
end if
m_datagridtablestyle = new datagridtablestyle
m_datagridtablestyle.mappingname = m_datatable.tablename
'//加columnstyle
dim mdatacolumn as datacolumn
dim mcolumnstyle as datagridcolumnstyle
for each mdatacolumn in m_datatable.columns
select case mdatacolumn.datatype.name
case "boolean"
mcolumnstyle = new datagridboolcolumn
case else
mcolumnstyle = new datagridtextboxcolumn
addhandler ctype(mcolumnstyle, datagridtextboxcolumn).textbox.doubleclick, addressof gridtextbox_doubleclick
end select
'//绑定到datatable的column
with mcolumnstyle
.mappingname = mdatacolumn.columnname
.headertext = mdatacolumn.columnname
end with
'//加入到datagridtablestyle
m_datagridtablestyle.gridcolumnstyles.add(mcolumnstyle)
next
'//将datagridtablestyle绑定到datagrid
m_datagrid.tablestyles.clear()
m_datagrid.tablestyles.add(m_datagridtablestyle)
end sub
'//自适应宽度
public sub autoextend()
if m_datagridtablestyle is nothing then exit sub
'取各字段的最大字节数，包括字段名和值
dim mrow as datarow
dim mcolumn as datacolumn
for each mcolumn in m_datatable.columns
m_datagridtablestyle.gridcolumnstyles(mcolumn.columnname).width = getcolumnmaxwidth(0, mcolumn.columnname)
next
for each mrow in m_datatable.rows
for each mcolumn in m_datatable.columns
if not isdbnull(mrow(mcolumn.columnname)) then
m_datagridtablestyle.gridcolumnstyles(mcolumn.columnname).width = _
getcolumnmaxwidth(m_datagridtablestyle.gridcolumnstyles(mcolumn.columnname).width, mrow(mcolumn.columnname).tostring)
end if
next
next
'参照datagrid的graphics赋实际宽度
for each mcolumnstyle as datagridcolumnstyle in m_datagridtablestyle.gridcolumnstyles
mcolumnstyle.width = columnwidth(mcolumnstyle.width)
next
end sub
private function getcolumnmaxwidth(byval maxwidth as integer, byval mstring as string) as integer
dim mlength as integer
mlength = system.text.encoding.default.getbytes(mstring).length()
if maxwidth < mlength then
return mlength
else
return maxwidth
end if
end function
private function columnwidth(byval maxwidth as integer) as integer
dim mgraphics as graphics = m_datagrid.creategraphics
dim mcolwidth as single
mcolwidth = mgraphics.measurestring(new string(ctype("a", char), maxwidth), m_datagrid.font).width + 2
return ctype(mcolwidth, integer)
end function
'//在某列后添加一列
public sub addcolumn(byval poscolumnname as string, byval columnname as string)
if m_datagridtablestyle is nothing then exit sub
if not m_datatable.columns.contains(poscolumnname) then exit sub
if m_datatable.columns.contains(columnname) then exit sub
dim tmpstyle as new datagridtablestyle
for each mcolumnstyle as datagridcolumnstyle in m_datagridtablestyle.gridcolumnstyles
tmpstyle.gridcolumnstyles.add(mcolumnstyle)
if mcolumnstyle.headertext.equals(poscolumnname) then
dim tmptextcolumn as new datagridtextboxcolumn
m_datatable.columns.add(columnname)
tmptextcolumn.headertext = columnname
tmptextcolumn.mappingname = columnname
tmpstyle.gridcolumnstyles.add(tmptextcolumn)
end if
next
m_datagrid.tablestyles.clear()
tmpstyle.mappingname = m_datagridtablestyle.mappingname
m_datagridtablestyle = tmpstyle
m_datagrid.tablestyles.add(m_datagridtablestyle)
end sub
'//不显示null
public writeonly property notshownull() as boolean
set(byval value as boolean)
for each mcolumnstyle as datagridcolumnstyle in m_datagridtablestyle.gridcolumnstyles
if value then
mcolumnstyle.nulltext = ""
else
mcolumnstyle.nulltext = "(null)"
end if
next
end set
end property
'//如果是日期类型，显示时间
public writeonly property showtimeformat() as boolean
set(byval value as boolean)
for each mcolumnstyle as datagridcolumnstyle in m_datagridtablestyle.gridcolumnstyles
if not mcolumnstyle.mappingname = "" andalso m_datatable.columns(mcolumnstyle.mappingname).datatype.name.indexof("date") <> -1 then
if value then
ctype(mcolumnstyle, datagridtextboxcolumn).format = "yyyy-mm-dd hh:mm:ss"
else
ctype(mcolumnstyle, datagridtextboxcolumn).format = "yyyy-mm-dd"
end if
end if
next
end set
end property
'个别编辑,除逻辑类型外
public readonly property textcolumnstyle(byval columnname as string) as datagridtextboxcolumn
get
if not m_datatable.columns(columnname) is nothing andalso not m_datatable.columns(columnname).datatype.name.equals("boolean") then
return ctype(m_datagridtablestyle.gridcolumnstyles(columnname), datagridtextboxcolumn)
else
return nothing
end if
end get
end property
end class
'测试
dim mytablestyle as new tablestyle
private sub button1_click(byval sender as system.object, byval e as system.eventargs) handles button1.click
dim ds as new dataset
me.sqlconnection1.open()
me.sqldataadapter1.fill(ds)
me.sqlconnection1.close()
me.datagrid1.datasource = ds.tables(0)
addhandler mytablestyle.gridtextboxdoubleclickevent, addressof
end sub
private sub button2_click(byval sender as system.object, byval e as system.eventargs) handles button2.click
with mytablestyle
.datagrid = me.datagrid1
.initialize()
end with
me.datagridtextcolumn_doubleclick
end sub
private sub button3_click(byval sender as system.object, byval e as system.eventargs) handles button3.click
mytablestyle.notshownull = true
mytablestyle.showtimeformat = true
end sub
private sub button4_click(byval sender as system.object, byval e as system.eventargs) handles button4.click
mytablestyle.notshownull = false
mytablestyle.showtimeformat = false
end sub
private sub button5_click(byval sender as system.object, byval e as system.eventargs) handles button5.click
mytablestyle.datagridtablestyle.gridcolumnstyles(2).readonly = true
end sub
private sub button6_click(byval sender as system.object, byval e as system.eventargs) handles button6.click
mytablestyle.addcolumn("姓名", "hello")
mytablestyle.autoextend()
end sub
private sub button7_click(byval sender as system.object, byval e as system.eventargs) handles button7.click
mytablestyle.textcolumnstyle("姓名").width=0
end sub
private sub datagridtextcolumn_doubleclick(byval sender as object, byval e as system.eventargs)
dim mtextbox as textbox = ctype(sender, textbox)
mtextbox.backcolor = system.drawing.color.blue
msgbox(mtextbox.text)
end sub
