Pythontkinter控件全集之组合选择框ttk.ComboBox

听雨者

Tkinter标准库Tkinter是Python的标准GUI库，也是最常用的PythonGUI库之一，提供了丰富的组件和功能，包括窗口、按钮、标签、文本框、列表框、滚动条、画布、菜单等，方便开发者进行图形界面的开发。Tkinter库基于TkforUnix/Windows/macOS，由Tcl语言编写。使用Tkinter，可以快速创建桌面应用程序，并支持多平台Windows、macOS、Linux等。tkinter控件全集在python中导入tkinter库后，有18种控件(也称组件)：导入方式：importtkinterastkButton、Canvas、Checkbutton、Entry、Frame、Label、LabelFrame、Listbox、Menu、Menubutton、Message、OptionMenu、PanedWindow、Radiobutton、Scale、Scrollbar、Spinbox、Text最学见的按钮、文本框、标签、列表框等都在里边，唯独没看到组合框ComboBox。查过资料后才知道，tkinter库中还有一子模块tkinter.ttk，它包含有包括Combobox在内的20种控件：导入方式：from tkinterimport ttkButton、Checkbutton、Combobox、Entry、Frame、Label、LabelFrame、LabeledScale、Labelframe、Menubutton、Notebook、OptionMenu、PanedWindow、Progressbar、Radiobutton、Scale、Scrollbar、Separator、Sizegrip、Spinbox、Treeview请注意，某些控件在两个模块中都存在（如Button, Checkbutton, Entry等），但它们在外观和行为上可能会有所不同，ttk模块中的控件可以提供更加现代和可定制的外观。以Button为例，都以简单的方式表达，运行后的外观和行为都有些不同。        importtkinterastk         fromtkinterimportttk        button1=tk.Button(root,text="ClickMe",command=button_click)        button2=ttk.Button(root,text="ClickMe",command=button_click)如图所示：完整代码如下：importtkinterastkfromtkinterimportttkdefbutton_click():print("Buttonclicked!")if__name__=='__main__':root=tk.Tk()root.title("Buttonvsttk.Button")root.geometry("400x300")button1=tk.Button(root,text="ClickMe",command=button_click)button1.pack(pady=60)button2=ttk.Button(root,text="ClickMe",command=button_click)button2.pack(pady=20)root.mainloop()以下将介绍今天的主角：ttk.Combobox组合选择框。ComboBox组合选择框ComboBox将几个文本字段组合成为一个可弹出的选择列表。它的原版帮助有3万多字呢，以下挑一些主要的操作方法简单介绍一下：创建并设置选择项  values=["Option1","Option2","Option3","Option4"]  combobox=ttk.Combobox(root,values=values)  combobox.pack()绑定事件ComboboxSelected  combobox.bind("<>",on_select)获取当前选择项combobox.get()combobox.get()以上插图的代码如下：importtkinterastkfromtkinterimportttkdefon_select(event):label.config(text="当前选择为："+combobox.get())if__name__=='__main__':#创建主窗口root=tk.Tk()root.title("ComboboxExample")root.geometry("400x300")label=tk.Label(root,text="请点击下拉框选择：")label.pack()#创建多选下拉框values=["Option1","Option2","Option3","Option4"]combobox=ttk.Combobox(root,values=values)combobox.pack()combobox.bind("<>",on_select)#运行主循环root.mainloop()设置当前显示项combobox.set()combobox.set()自定义类 SelectCombobox把以上内容综合起来，自定义一个组合框类： importtkinterastkfromtkinterimportttkclassSelectCombobox(ttk.Combobox):def__init__(self,master=None,values=None):super().__init__(master,values=values)self.bind("<>",self.on_select)defon_select(self,event):label.config(text="当前选择为："+self.get())if__name__=='__main__':#创建主窗口root=tk.Tk()root.title("ComboboxExample")root.geometry("400x300")label=tk.Label(root,text="请点击下拉框选择：")label.pack()#创建多选下拉框values=["Option1","Option2","Option3","Option4"]combobox=SelectCombobox(root,values=values)combobox.pack()#运行主循环root.mainloop()扩展Combobox组合框拓展成多项选择Combobox本身不支持多项选择，变通方法：引入一个列表，用于存放已选项，奇数次选择一个项则存入列表、反之偶数次选择则移除。代码如下：importtkinterastkfromtkinterimportttkclassMultiSelectCombobox(ttk.Combobox):def__init__(self,master=None,values=None,**kwargs):super().__init__(master,values=values,**kwargs)self.bind("<>",self.on_select)self.selected_values=[]defon_select(self,event):selected_value=self.get()#使用get方法获取选中项的值ifselected_valueinself.selected_values:self.selected_values.remove(selected_value)#如果已选中，则移除该选项else:self.selected_values.append(selected_value)#如果未选中，则添加到已选项列表self.selected_values.sort()ifself.selected_values:text='、'.join(self.selected_values)else:text='空'label2.config(text="当前选择为："+text)if__name__=='__main__':#创建主窗口root=tk.Tk()root.title("Multi-SelectComboboxExample")root.geometry("400x300")label=tk.Label(root,text="请选择：")label.pack()#创建多选下拉框values=["Option1","Option2","Option3","Option4"]combobox=MultiSelectCombobox(root,values=values)combobox.pack()text="当前选择为：空"label2=tk.Label(root,text=text)label2.pack()#运行主循环root.mainloop()选项前添加符号Combobox本身不支持修改选择项，变通方法：在每次变更选项时都重建一个新的组合框，同时把所有的选项前都加上一个全角空格(\u3000)，对于已选中的选项，则把前面的全角空格替换成对勾符号(\u2713)。这样子可能更像一个多项选择框，如下图：代码如下：importtkinterastkfromtkinterimportttkdefon_select(event):selected_value=combobox.get()selected_value=selected_value.replace("\u2713","\u3000")ifselected_valueinselected_values:selected_values.remove(selected_value)else:selected_values.append(selected_value)selected_values.sort()ifselected_values:text='、'.join(selected_values).replace('tion','')else:text='空'label.config(text="当前选择为："+text)update_combobox_options()defupdate_combobox_options():globalcomboboxcombobox.grid_forget()new_values=[]forvinvalues:ifvinselected_values:new_values.append(v.replace("\u3000","\u2713"))else:new_values.append(v)combobox=ttk.Combobox(root,values=new_values,state='readonly')combobox.place(x=100,y=30)combobox.set('请点击选择：')combobox.bind("<>",on_select)if__name__=='__main__':#创建主窗口root=tk.Tk()root.title("Multi-SelectComboboxExample")root.geometry("400x300")#创建多选下拉框values=["Option1","Option2","Option3","Option4"]values=["\u3000"+vforvinvalues]selected_values=[]combobox=ttk.Combobox(root,values=values,state='readonly')combobox.place(x=100,y=30)combobox.set('请点击选择：')combobox.bind("<>",on_select)text="当前选择为：空"label=tk.Label(root,text=text)label.pack(side=tk.BOTTOM)#运行主循环root.mainloop()题外话以上这些是我自己瞎写的变通代码，可能有更好的办法来实现这些功能，也有可能ttk模块本身就有这些功能，只是我没发现而已。另外：如果选择项不至是四个而是有很多，最好能在最前面设置两个选项，全部选择和取消全选，它们不参与进入已选项列表，点击它们只为在其它选项上标注对勾同时填满或清空已选项列表。感兴趣的朋友，可以自己动手实现这两个功能。附件一Combobox英文帮助HelponclassComboboxinmoduletkinter.ttk:classCombobox(Entry) | Combobox(master=None,**kw) |  | TtkComboboxwidgetcombinesatextfieldwithapop-downlistofvalues. |  | Methodresolutionorder: |   Combobox |   Entry |   Widget |   tkinter.Entry |   tkinter.Widget |   tkinter.BaseWidget |   tkinter.Misc |   tkinter.Pack |   tkinter.Place |   tkinter.Grid |   tkinter.XView |   builtins.object |  | Methodsdefinedhere: |  | __init__(self,master=None,**kw) |   ConstructaTtkComboboxwidgetwiththeparentmaster. |    |   STANDARDOPTIONS |    |     class,cursor,style,takefocus |    |   WIDGET-SPECIFICOPTIONS |    |     exportselection,justify,height,postcommand,state, |     textvariable,values,width |  | current(self,newindex=None) |   Ifnewindexissupplied,setsthecomboboxvaluetothe |   elementatpositionnewindexinthelistofvalues.Otherwise, |   returnstheindexofthecurrentvalueinthelistofvalues |   or-1ifthecurrentvaluedoesnotappearinthelist. |  | set(self,value) |   Setsthevalueofthecomboboxtovalue. |  | ---------------------------------------------------------------------- | MethodsinheritedfromEntry: |  | bbox(self,index) |   Returnatupleof(x,y,width,height)whichdescribesthe |   boundingboxofthecharactergivenbyindex. |  | identify(self,x,y) |   Returnsthenameoftheelementatpositionx,y,orthe |   emptystringifthecoordinatesareoutsidethewindow. |  | validate(self) |   Forcerevalidation,independentoftheconditionsspecified |   bythevalidateoption.ReturnsFalseifvalidationfails,True |   ifitsucceeds.Setsorclearstheinvalidstateaccordingly. |  | ---------------------------------------------------------------------- | MethodsinheritedfromWidget: |  | instate(self,statespec,callback=None,*args,**kw) |   Testthewidget'sstate. |    |   Ifcallbackisnotspecified,returnsTrueifthewidgetstate |   matchesstatespecandFalseotherwise.Ifcallbackisspecified, |   thenitwillbeinvokedwith*args,**kwifthewidgetstate |   matchesstatespec.statespecisexpectedtobeasequence. |  | state(self,statespec=None) |   Modifyorinquirewidgetstate. |    |   WidgetstateisreturnedifstatespecisNone,otherwiseitis |   setaccordingtothestatespecflagsandthenanewstatespec |   isreturnedindicatingwhichflagswerechanged.statespecis |   expectedtobeasequence. |  | ---------------------------------------------------------------------- | Methodsinheritedfromtkinter.Entry: |  | delete(self,first,last=None) |   DeletetextfromFIRSTtoLAST(notincluded). |  | get(self) |   Returnthetext. |  | icursor(self,index) |   InsertcursoratINDEX. |  | index(self,index) |   Returnpositionofcursor. |  | insert(self,index,string) |   InsertSTRINGatINDEX. |  | scan_dragto(self,x) |   Adjusttheviewofthecanvasto10timesthe |   differencebetweenXandYandthecoordinatesgivenin |   scan_mark. |  | scan_mark(self,x) |   RememberthecurrentX,Ycoordinates. |  | select_adjust=selection_adjust(self,index) |  | select_clear=selection_clear(self) |  | select_from=selection_from(self,index) |  | select_present=selection_present(self) |  | select_range=selection_range(self,start,end) |  | select_to=selection_to(self,index) |  | selection_adjust(self,index) |   AdjusttheendoftheselectionnearthecursortoINDEX. |  | selection_clear(self) |   Cleartheselectionifitisinthiswidget. |  | selection_from(self,index) |   SetthefixedendofaselectiontoINDEX. |  | selection_present(self) |   ReturnTrueiftherearecharactersselectedintheentry,False |   otherwise. |  | selection_range(self,start,end) |   SettheselectionfromSTARTtoEND(notincluded). |  | selection_to(self,index) |   SetthevariableendofaselectiontoINDEX. |  | ---------------------------------------------------------------------- | Methodsinheritedfromtkinter.BaseWidget: |  | destroy(self) |   Destroythisandalldescendantswidgets. |  | ---------------------------------------------------------------------- | Methodsinheritedfromtkinter.Misc: |  | __getitem__=cget(self,key) |  | __repr__(self) |   Returnrepr(self). |  | __setitem__(self,key,value) |  | __str__(self) |   Returnthewindowpathnameofthiswidget. |  | after(self,ms,func=None,*args) |   Callfunctiononceaftergiventime. |    |   MSspecifiesthetimeinmilliseconds.FUNCgivesthe |   functionwhichshallbecalled.Additionalparameters |   aregivenasparameterstothefunctioncall. Return |   identifiertocancelschedulingwithafter_cancel. |  | after_cancel(self,id) |   CancelschedulingoffunctionidentifiedwithID. |    |   Identifierreturnedbyafterorafter_idlemustbe |   givenasfirstparameter. |  | after_idle(self,func,*args) |   CallFUNConceiftheTclmainloophasnoeventto |   process. |    |   Returnanidentifiertocanceltheschedulingwith |   after_cancel. |  | anchor=grid_anchor(self,anchor=None) |  | bell(self,displayof=0) |   Ringadisplay'sbell. |  | bind(self,sequence=None,func=None,add=None) |   BindtothiswidgetateventSEQUENCEacalltofunctionFUNC. |    |   SEQUENCEisastringofconcatenatedevent |   patterns.Aneventpatternisoftheform |   whereMODIFIERisone |   ofControl,Mod2,M2,Shift,Mod3,M3,Lock,Mod4,M4, |   Button1,B1,Mod5,M5Button2,B2,Meta,M,Button3, |   B3,Alt,Button4,B4,Double,Button5,B5Triple, |   Mod1,M1.TYPEisoneofActivate,Enter,Map, |   ButtonPress,Button,Expose,Motion,ButtonRelease |   FocusIn,MouseWheel,Circulate,FocusOut,Property, |   Colormap,GravityReparent,Configure,KeyPress,Key, |   Unmap,Deactivate,KeyReleaseVisibility,Destroy, |   LeaveandDETAIListhebuttonnumberforButtonPress, |   ButtonReleaseandDETAIListheKeysymforKeyPressand |   KeyRelease.Examplesare |   forpressingControlandmousebutton1or |   <<