1. BMI App (Bio Mass Index)

 

App Manifest:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools">

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:supportsRtl="true"
        android:theme="@style/Theme.BMIApp"
        tools:targetApi="31">
        <activity
            android:name=".MainActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
    </application>

</manifest>

1. Java Code: 

package com.example.bmiapp;

import static com.example.bmiapp.R.color.colorO;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.LinearLayout;
import android.widget.TextView;

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        EditText edtWeight, edtHeightFt, edtHeightIn;
        Button btnCalculate;
        TextView txtResult;
        LinearLayout llMain;

        edtWeight = findViewById(R.id.edtWeight);
        edtHeightFt = findViewById(R.id.edtHeightFt);
        edtHeightIn = findViewById(R.id.edtHeightIn);
        btnCalculate = findViewById(R.id.btnCalculate);
        txtResult = findViewById(R.id.txtResult);
        llMain = findViewById(R.id.llMain);

        btnCalculate.setOnClickListener(new View.OnClickListener(){

            @Override
            public void onClick(View v) {
                int wt = Integer.parseInt(edtWeight.getText().toString());
                int ft = Integer.parseInt(edtHeightFt.getText().toString());
                int in = Integer.parseInt(edtHeightIn.getText().toString());


                int totalIn = ft*12 + in;
                double totalcm = totalIn*2.53;
                double totalM = totalcm/100;
                double bmi = wt/(totalM*totalM);

                if(bmi>25){
                    txtResult.setText("You'r OverWeight!");
                    llMain.setBackgroundColor(getResources().getColor(R.color.colorO));
                } else if (bmi<18) {
                    txtResult.setText("You'r underWeight!");
                    llMain.setBackgroundColor(getResources().getColor(R.color.colorU));
                }else {
                    txtResult.setText("You'r Healthy!");
                    llMain.setBackgroundColor(getResources().getColor(R.color.colorH));
                }
            }
        });
    }
}

2. XML Layout Code:

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center"
    android:id="@+id/llMain"
    tools:context=".MainActivity">

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:hint="@string/hint_wt"
        android:id="@+id/edtWeight"
        android:inputType="number"/>

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:hint="@string/hint_hF"
        android:id="@+id/edtHeightFt"
        android:inputType="number"/>

    <EditText
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:ems="10"
        android:hint="@string/hint_hI"
        android:id="@+id/edtHeightIn"
        android:inputType="number"/>

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="11dp"
        android:text="Calculate BMI"
        android:id="@+id/btnCalculate"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id="@+id/txtResult"
        android:text="Result"
        android:textSize="21sp"
        android:textStyle="bold"
        android:layout_marginTop="11dp"/>

    <TextView
        android:id="@+id/txtResult"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="11dp"
        android:gravity="bottom"
        android:text="Sadam Hussain Mahar"
        android:textSize="28sp"
        android:textStyle="bold" />

</LinearLayout>