以标准体重计算器为例演示

为例演示"/>

以标准体重计算器为例演示

页面设计：

 

页面布局：

在标准体重计算器中，点击所属性别，输入身高，按计算根据性别进行标准体重计算。并在另一个页面中显示计算结果。

activity_main.xml

<LinearLayout xmlns:android=""xmlns:tools=""android:layout_width="fill_parent"android:layout_height="fill_parent"android:orientation="vertical"android:background="@drawable/ic_picture"tools:context=".MainActivity" ><TextViewandroid:layout_width="wrap_content"android:layout_height="wrap_content"android:text="@string/title" /><TextViewandroid:id="@+id/xingbie"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="@string/xingbie" /><RadioGroupandroid:id="@+id/radioGroup1"android:layout_width="wrap_content"android:layout_height="122dp" ><RadioButtonandroid:id="@+id/man"android:layout_width="wrap_content"android:layout_height="wrap_content"            android:text="@string/man" /><RadioButtonandroid:id="@+id/woman"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="@string/woman" /></RadioGroup><TextViewandroid:id="@+id/shengao"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="@string/high" /><EditTextandroid:id="@+id/height"android:layout_width="fill_parent"android:layout_height="wrap_content"android:ems="10" ></EditText><Buttonandroid:id="@+id/button_count"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="@string/click" /></LinearLayout>

activity_second_main.xml:

<LinearLayout xmlns:android=""xmlns:tools=""android:layout_width="fill_parent"android:layout_height="fill_parent"    android:orientation="vertical"android:background="@drawable/ic_picture"tools:context=".SecondMainActivity" ><TextViewandroid:id="@+id/answer"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="@string/text" /><Buttonandroid:id="@+id/back"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="@string/back" /></LinearLayout>

string.xml:

<?xml version="1.0" encoding="utf-8"?>
<resources><string name="app_name">标准体重计算器</string><string name="action_settings">Settings</string><string name="title">计算你的标准体重</string><string name="xingbie">性别：</string><string name="man">男性</string><string name="woman">女性</string><string name="high">身高：</string><string name="click">计 算</string><string name="title_activity_second_main">标准体重计算器</string><string name="text"></string><string name="back">返 回</string></resources>

代码实现：

MainActivity.java

package bzu.weight_calculator;import android.os.Bundle;import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.RadioGroup;
import android.widget.RadioGroup.OnCheckedChangeListener;public class MainActivity extends Activity {private Button calculator;private EditText high;private RadioGroup radioGroup;private RadioButton man,woman;String sex;String height;private int h;private double w;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_main);initialComponents();Intent intent=getIntent();sex=intent.getStringExtra("sex");height=intent.getStringExtra("height");if(sex!=null && sex.equals("男性")){man.setChecked(true);}if(sex!=null && sex.equals("女性")){woman.setChecked(true);}if(height!=null){high.setText(height);}		radioGroup.setOnCheckedChangeListener(new OnCheckedChangeListener() {@Overridepublic void onCheckedChanged(RadioGroup group, int checkedId) {switch (checkedId) {case R.id.man:sex=man.getText().toString();break;case R.id.woman:sex=woman.getText().toString();break;				}				}});calculator.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubString str=high.getText().toString();h=Integer.parseInt(str);if(man.equals("男性")){w=(h-80)*0.7;IntentBundle();//Toast.makeText(MainActivity.this, "你是一名"+man.getText().toString()+"性\n你的身高是"+str+"\n 你的标准体重为"+w+"公斤",Toast.LENGTH_LONG ).show();}else{w=(h-70)*0.6;IntentBundle();//Toast.makeText(MainActivity.this, "你是一名"+woman.getText().toString()+"性\n 你的身高是"+str+"\n 你的标准体重为"+w+"公斤",Toast.LENGTH_LONG ).show();}}});}private void initialComponents(){calculator=(Button) this.findViewById(R.id.button_count);high=(EditText) this.findViewById(R.id.height);radioGroup=(RadioGroup) this.findViewById(R.id.radioGroup1);man=(RadioButton) this.findViewById(R.id.man);woman=(RadioButton) this.findViewById(R.id.woman);}private void IntentBundle(){Intent intent=new Intent();		intent.putExtra("sex", sex);intent.putExtra("height", h);intent.putExtra("weight", w);intent.setClass(MainActivity.this, SecondMainActivity.class);startActivity(intent);//finish();}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.main, menu);return true;}
}

SecondMainActivity.java:

package bzu.weight_calculator;import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;public class SecondMainActivity extends Activity {private TextView answer;private Button back;Intent intent;String sex;private int height;double weight;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.activity_second_main);answer=(TextView) this.findViewById(R.id.answer);back=(Button) this.findViewById(R.id.back);intent=getIntent();Bundle bundle=intent.getExtras();sex=bundle.getString("sex");height=bundle.getInt("height");double weight=bundle.getDouble("weight");answer.setText("你是一名"+sex+"\n您的身高为："+height+"\n你的标准体重为："+weight+"公斤！");back.setOnClickListener(new OnClickListener() {@Overridepublic void onClick(View v) {// TODO Auto-generated method stubIntent intent=new Intent();intent.setClass(SecondMainActivity.this, MainActivity.class);intent.putExtra("sex", sex);intent.putExtra("height", height);startActivity(intent);//finish();}});}@Overridepublic boolean onCreateOptionsMenu(Menu menu) {// Inflate the menu; this adds items to the action bar if it is present.getMenuInflater().inflate(R.menu.second_main, menu);return true;}
}

心得体会：
在制作标准体重计算器时，简单的制作成功了计算的功能，其后在返回主页面时出现错误，没有保存数据，点击计算时起身高传的时传null。检查后时RadioGroup出现错误，制定了默认的值。 EditText中的id定义的与java文件里的不一致忠造成的。