体重测仪器

package irdc.ex03_11;

/* import相关class */
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 EX03_11 extends Activity 
{
  private EditText et;
  private RadioButton rb1;
  private RadioButton rb2;
    
  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) 
  {
    super.onCreate(savedInstanceState);
    /* 载入main.xml Layout */
    setContentView(R.layout.main);
    
    /* 以findViewById()取得Button对象，并添加onClickListener */
    Button b1 = (Button) findViewById(R.id.button1);
    b1.setOnClickListener(new Button.OnClickListener()
    {
      public void onClick(View v)
      {
        /*取得输入的身高*/
        et = (EditText) findViewById(R.id.height);
        double height=Double.parseDouble(et.getText().toString());
        /*取得选择的性别*/
        String sex="";
        rb1 = (RadioButton) findViewById(R.id.sex1);
        rb2 = (RadioButton) findViewById(R.id.sex2);
        if(rb1.isChecked())
        {
          sex="M";
        }
        else
        {
          sex="F";
        }    
        
        /*new一个Intent对象，并指定class*/
        Intent intent = new Intent();
        intent.setClass(EX03_11.this,EX03_11_1.class);
        
        /*new一个Bundle对象，并将要传递的数据传入*/
        Bundle bundle = new Bundle();
        bundle.putDouble("height",height);
        bundle.putString("sex",sex);
      
        /*将Bundle对象assign给Intent*/
        intent.putExtras(bundle);
      
        /*调用Activity EX03_11_1*/
        startActivityForResult(intent,0);
      }
    });
  }
  
  /* 覆盖 onActivityResult()*/
  @Override
  protected void onActivityResult(int requestCode, int resultCode,
                                  Intent data)
  {
    switch (resultCode)
    { 
      case RESULT_OK:
        /* 取得来自Activity2的数据，并显示于画面上 */  
        Bundle bunde = data.getExtras();
        String sex = bunde.getString("sex");
        double height = bunde.getDouble("height");
        
        et.setText(""+height);
        if(sex.equals("M"))
        {
          rb1.setChecked(true);
        }
        else
        {
          rb2.setChecked(true);
        }
        break;
      default:
        break;
     } 
   } 
}

package irdc.ex03_11;

/* import相关class */
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 EX03_11_1 extends Activity 
{
  Bundle bunde;
  Intent intent;
  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) 
  {
    super.onCreate(savedInstanceState);
    /* 载入mylayout.xml Layout */
    setContentView(R.layout.myalyout);
    
    /* 取得Intent中的Bundle对象 */
    intent=this.getIntent();
    bunde = intent.getExtras();
    
    /* 取得Bundle对象中的数据 */
    String sex = bunde.getString("sex");
    double height = bunde.getDouble("height");
    
    /* 判断性别 */
    String sexText="";
    if(sex.equals("M"))
    {
      sexText="男性";
    }
    else
    {
      sexText="女性";
    }
    
    /* 取得标准体重 */
    String weight=this.getWeight(sex, height);
    
    /* 设置输出文字 */
    TextView tv1=(TextView) findViewById(R.id.text1);
    tv1.setText("你是一位"+sexText+"\n你的身高是"+height+
                   "厘米\n你的标准体重是"+weight+"公斤");
    
    /* 以findViewById()取得Button对象，并添加onClickListener */
    Button b1 = (Button) findViewById(R.id.button1);
    b1.setOnClickListener(new Button.OnClickListener()
    {
      public void onClick(View v)
      {          
        /* 返回result回上一个activity */
        EX03_11_1.this.setResult(RESULT_OK, intent);
        
        /* 结束这个activity */
        EX03_11_1.this.finish();
      }
    });
  }
  
  /* 四舍五入的method */
  private String format(double num)
  {
    NumberFormat formatter = new DecimalFormat("0.00");
    String s=formatter.format(num);
    return s;
  }

  /* 以findViewById()取得Button对象，并添加onClickListener */  
  private String getWeight(String sex,double height)
  {
    String weight="";
    if(sex.equals("M"))
    {
      weight=format((height-80)*0.7);
    }
    else
    {
      weight=format((height-70)*0.6);
    }  
    return weight;
  }
}

 这段代码用来返回上一个activity

Button b1 = (Button) findViewById(R.id.button1);
    b1.setOnClickListener(new Button.OnClickListener()
    {
      public void onClick(View v)
      {         
        /* 返回result回上一个activity */
        EX03_11_1.this.setResult(RESULT_OK, intent);
       
        /* 结束这个activity */
        EX03_11_1.this.finish();
      }
    });

设置EditText显示或隐藏密码.

在CheckBox的onCheckedChanged()方法中, 判断是否选中.

if (isChecked) {
			System.out.println("checked");
			// 显示密码
			password_edit.setInputType(InputType.TYPE_TEXT_VARIATION_VISIBLE_PASSWORD); 
		} else {
			System.out.println("not checked");
			// 隐藏密码
			password_edit.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);
		}