calculator widgets for android

(Edittext.gettext (). toString ()));//Save the value of the display area and calculate}Save the operator you clicked onLastcommand = Inputcommand;Clearflag = true;//Because I've already entered the operator here,}}}Method of calculationprivate void Calculate (Double x) {if (lastcommand.equals ("+")) {result + = x;} else if (Lastcommand.equals ("-")) {Result-= x;} else if (Lastcommand.equals ("*")) {Result *= x;} else if (Lastcommand.equals ("/")) {Result/= x;} else if (lastcommand.equals ("="))

2017.4.1Today the layout interface is basically complete and now writes a bit of event binding. The plan is to use dynamic bindings and change them at any time. About the layout, yesterday to get very late, because the layout of the use of errors, with the own, not carefully read, preview without problems, but the real machine debugging error. is a compatibility issue, many Android systems do not support Constrainlayout (6.0 does not support do not as

Reprint Please specify source: http://blog.csdn.net/qq_32059827/article/details/51707931From today onwards, this column continues to update the Android Simple Combat blog post. Unlike previous columns, this column has only instances. Each instance as far as possible according to the knowledge points corresponding to the content of the corresponding chapter to write, step-by. Some instances may have duplicate articles with another column.The first simp

())-Float.parsefloat (Medittext1.gettext ( ). ToString ()); } if (operation== "*") {temp=float.parsefloat (Medittext.gettext (). toString ()) * Float.parsefloat (Medittext1.gettext ( ). ToString ()); } if (operation== "/") {Temp=float.parsefloat (Medittext.gettext (). toString ())/Float.parsefloat (Medittext1.gettext ( ). ToString ()); } experssion=medittext.gettext (). ToString () +operation+medittext1.gettext (). ToString () + "=" +temp.tostring (); return experssion; The public void Confirm

Algorithm used: expression evaluation (infix expression to suffix expression, suffix expression evaluation value)Not how to design the interface, there is time to beautify!Mainactivity.javaPackage Com.example.calculator;import Java.util.hashmap;import Java.util.linkedlist;import java.util.List;import Java.util.map;import Android.app.activity;import Android.os.bundle;import Android.view.menu;import Android.view.view;import Android.widget.button;import Android.widget.textview;import Android.widget

1.activity_main.xml File Layout　　2.mainfest.xml settingsThe writing of 3.color.xml4.drawable Create White_bg.xml as EditText white background　　①②③④Android Calculator maker 1. Layout

; Android:layout_height= "Wrap_content"Android:layout_weight= "1"Android:text= "9"/> Android:layout_height= "Wrap_content"Android:layout_weight= "1"Android:text= "x"/> Android:layout_height= "Wrap_content"Android:layout_weight= "1"Android:text= "4"/> Android:layout_height= "Wrap_content"Android:layout_weight= "1"Android:text= "5"/> Android:layout_height= "Wrap_content"Android:layout_weight= "1"Android:text= "6"/> Android:layout_height= "Wrap_content"Android:layout_weight= "1"Android:text= "-"/>