在輸入性別 , 身高及體重後 , 按下計算按鈕 , 在Activity 中運用Intent傳遞資訊並啟動另一個Activity , 並計算BMI值 , 這題重點在兩個Activity的資料傳遞 , 記得要在AndroidManifest.xml 宣告另一支Activity, 以下是程式碼。
package COM.TQC.GDD01;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.RadioButton;
public class GDD01 extends Activity
{
private EditText etheight , etweight;
private RadioButton rb1 , rb2;
final int RequestCode = 0;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
etheight = (EditText) findViewById(R.id.editText1);
etweight = (EditText) findViewById(R.id.editText2);
rb1 = (RadioButton) findViewById(R.id.radioButton1);
rb1.setChecked(true);
rb2 = (RadioButton) findViewById(R.id.radioButton2);
Button b1 = (Button) findViewById(R.id.button1);
b1.setOnClickListener(new Button.OnClickListener()
{
public void onClick(View v)
{
Bundle bundle = new Bundle();
if(rb1.isChecked()) bundle.putString("Sex", "M");
else bundle.putString("Sex", "F");
bundle.putDouble("height", Double.parseDouble(etheight.getText().toString()));
bundle.putDouble("weight", Double.parseDouble(etweight.getText().toString()));
Intent intent = new Intent();
intent.setClass(GDD01.this, GDD01_child.class);
intent.putExtras(bundle);
GDD01.this.startActivityForResult(intent, RequestCode);
/*
從輸入介面中取出了的身高、體重值，要將身高、體重值傳送給 child_Activity 後作計算
這些附加在 Intent 上的訊息都儲存在 Bundle 物件中
透過「intent.putExtras(bundle)」敘述，將「bundle」 物件附加在 Intent 上，
隨著 Intent 送出而送出
*/
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
switch (resultCode)
{
case RESULT_OK:
Bundle bundle = data.getExtras();
String Sex = bundle.getString("Sex");
double height = bundle.getDouble("height");
double weight = bundle.getDouble("weight");
etheight.setText("" + height);
etweight.setText("" + weight);
if(Sex.equals("M"))
{
rb1.setChecked(true);
}else
{
rb2.setChecked(true);
}
break;
default:
break;
}
}
}
另一個Activity
package COM.TQC.GDD01 ;
import java.text.DecimalFormat;
import java.text.NumberFormat;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
public class GDD01_child extends Activity
{
Bundle bundle;
Intent intent;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.mylayout);
intent=this.getIntent();
bundle = intent.getExtras();
String Sex = bundle.getString("Sex");
double height = bundle.getDouble("height");
double weight = bundle.getDouble("weight");
String BMI_result = this.getBMI(height,weight);
String BMI_advice = this.getAdvice(Sex,height,weight);
TextView tvBMI = (TextView) findViewById(R.id.tvBMI);
tvBMI.setText("BMI 結果" + BMI_result);
TextView tvAdvice = (TextView) findViewById(R.id.tvAdvice);
tvAdvice.setText(BMI_advice);
Button b1 = (Button) findViewById(R.id.button1);
b1.setOnClickListener(new Button.OnClickListener()
{
public void onClick(View v)
{
GDD01_child.this.setResult(RESULT_OK, intent);
GDD01_child.this.finish();
}
});
}
//BMI值格式化
private String format(double num)
{
NumberFormat NF = new DecimalFormat(".##");
return NF.format(num);
}
//取得BMI值
private String getBMI (double height, double weight)
{
double BMI = weight / Math.pow(height, 2);
return format(BMI);
}
//依BMI值取得建議
private String getAdvice (String Sex, double height, double weight)
{
double doubleBMI = Double.parseDouble(getBMI(height,weight));
String Advice;
if(Sex.equals("m"))
{
if(doubleBMI>25) Advice = (String) getText(R.string.advice_heavy);
else if(doubleBMI<20) Advice = (String) getText(R.string.advice_light);
else Advice = (String) getText(R.string.advice_average);
}
else
{
if(doubleBMI>22) Advice = (String) getText(R.string.advice_heavy);
else if(doubleBMI<18) Advice = (String) getText(R.string.advice_light);
else Advice = (String) getText(R.string.advice_average);
}
return Advice;
}
}
main.xml
mylayout.xml
最後是AndroidManifest.xml
P.S. 題目中所要求的Variable和Method皆會保留 , 也會根據題目所要求的流程去實作 , 縱使題目要求繞遠路....
