一個通用的DataGridTableStyle的做法
2024-07-21 02:23:09
供稿：網友
一個通用的datagridtablestyle的做法
哈，這兩天都喜歡寫“通用”的東西。
這個類，可以實現自適應列寬、只讀、時分顯示、事件、任意位置加列、單擊單元格背景色設置等等，操作簡便。只是時間關系（明天要出去一趟），今天沒辦法完善。僅供參考，你可以加入別的東西。以下只列代碼了，不清楚的自己試用查資料就行了。
public class tablestyle
private m_datagridtablestyle as datagridtablestyle
private m_datagrid as datagrid
private m_datatable as datatable
'//添加事件處理，在此只考慮datagridtextboxcolumn雙擊事件
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
'//設置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()
'//判斷mdatagrid數據源類型
'//如果綁定的是dataset或dataviewmanager或沒有綁定任何數據源，則退出,
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
'//以下分別考慮兩種數據源，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
'//綁定到datatable的column
with mcolumnstyle
.mappingname = mdatacolumn.columnname
.headertext = mdatacolumn.columnname
end with
'//加入到datagridtablestyle
m_datagridtablestyle.gridcolumnstyles.add(mcolumnstyle)
next
'//將datagridtablestyle綁定到datagrid
m_datagrid.tablestyles.clear()
m_datagrid.tablestyles.add(m_datagridtablestyle)
end sub
'//自適應寬度
public sub autoextend()
if m_datagridtablestyle is nothing then exit sub
'取各字段的最大字節數，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
'參照datagrid的graphics賦實際寬度
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
'//不顯示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
'//如果是日期類型，顯示時間
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
'個別編輯,除邏輯類型外
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
'測試
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
