Anroid Studio 用简单代码实现BMI计算器并且将应用安装到手机上

【Anroid Studio 用简单代码实现BMI计算器并且将应用安装到手机上】第一步：创建工程：
第二步：编写前端页面：找到content_main.xml:
具体代码如下：第三步：编写后端：找到MainActivity类：里面需要注意编写的每一个组件的id需要一致。
package com.example.myapplication777;import android.icu.text.Edits;import android.os.Bundle;import com.google.android.material.snackbar.Snackbar;import androidx.appcompat.app.AppCompatActivity;import android.util.Log;import android.view.View;import androidx.navigation.NavController;import androidx.navigation.Navigation;import androidx.navigation.ui.AppBarConfiguration;import androidx.navigation.ui.NavigationUI;import com.example.myapplication777.databinding.ActivityMainBinding;import android.view.Menu;import android.view.MenuItem;import android.widget.EditText;import android.widget.TextView;public class MainActivity extends AppCompatActivity {private AppBarConfiguration appBarConfiguration;private ActivityMainBinding binding;//计算publicfloat height=0f;publicfloat weight=0f;publicfloat result=0f;//输入框的属性EditText editText1=null;EditText editText2=null;TextViewtextView =null;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);binding = ActivityMainBinding.inflate(getLayoutInflater());setContentView(binding.getRoot());setSupportActionBar(binding.toolbar);//实例化//身高体重editText1=(EditText)findViewById(R.id.editTextTextPersonName);editText2=(EditText)findViewById(R.id.editTextTextPersonName2);//显示结果textView=(TextView)findViewById(R.id.textView4);NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment_content_main);appBarConfiguration = new AppBarConfiguration.Builder(navController.getGraph()).build();NavigationUI.setupActionBarWithNavController(this, navController, appBarConfiguration);binding.fab.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View view) {Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG).setAction("Action", null).show();}});}//计算publicvoid onClick(View view){Log.d("TAG","--------点击了计算按钮-------");height= Float.parseFloat(editText1.getText().toString());height=height/100f;weight= Float.parseFloat(editText2.getText().toString());result=weight/(height*height);textView.setText("您的BMI值为："+result);}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.menu_main, menu);return true;}@Overridepublic boolean onOptionsItemSelected(MenuItem item) {// Handle action bar item clicks here. The action bar will// automatically handle clicks on the Home/Up button, so long// as you specify a parent activity in AndroidManifest.xml.int id = item.getItemId();//noinspection SimplifiableIfStatementif (id == R.id.action_settings) {return true;}return super.onOptionsItemSelected(item);}@Overridepublic boolean onSupportNavigateUp() {NavController navController = Navigation.findNavController(this, R.id.nav_host_fragment_content_main);return NavigationUI.navigateUp(navController, appBarConfiguration)|| super.onSupportNavigateUp();}} 第四步：调试
如果因为gradle版本的问题可以看前面一期。
第五步：安装到手机
进行安装即可，出现安卓手机版本问题需要调一下sdk 。最后手机上安装成功。