AndroidStudio实现长方体表面积计算器

package com.example.flyyu.four;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

import java.util.regex.Pattern;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_main);
 }
 @Override
 public void onClick(View v) {
 EditText a=(EditText)findViewById(R.id.editText);

 EditText b=(EditText)findViewById(R.id.editText2);

 EditText c=(EditText)findViewById(R.id.editText3);
 Intent it=new Intent(this,biapmianji.class);
 if (!isNumber(a.getText().toString())&&!isNumber(b.getText().toString())&&!isNumber(c.getText().toString())){
 it.putExtra("a",a.getText().toString());
 it.putExtra("b",b.getText().toString());
 it.putExtra("c",c.getText().toString());
 MainActivity.this.startActivity(it);
 }
 }
 public boolean isNumber(String s){

 String pattern = ".*\\D.*";

 boolean isMatch = Pattern.matches(pattern,s);
 if (isMatch||s.length()==0){
 Toast.makeText(this,"输入异常",Toast.LENGTH_SHORT).show();
 return true;
 }
 return isMatch;
 }
}

package com.example.flyyu.four;

import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.TextView;

public class biapmianji extends AppCompatActivity {

 @Override
 protected void onCreate(Bundle savedInstanceState) {
 super.onCreate(savedInstanceState);
 setContentView(R.layout.activity_biapmianji);
 TextView textView=(TextView)findViewById(R.id.textView4);
 Intent it=this.getIntent();
 float a=Float.valueOf(it.getStringExtra("a")) ;
 float b=Float.valueOf(it.getStringExtra("b")) ;
 float c=Float.valueOf(it.getStringExtra("c")) ;
 String s=(2*(a*b+a*c+b*c))+"";
 textView.setText("该长方体的表面积为:"+s);

// textView.setText("该长方体的表面积为:"+a);
 }


}

<&＃63;xml version="1.0" encoding="utf-8"&＃63;>


 

<&＃63;xml version="1.0" encoding="utf-8"&＃63;>