Android學習筆記-GDD02 解題

package COM.TQC.GDD02;
import android.app.Activity;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class GDD02 extends Activity {
 public static final String PREF_NAME = "GDD02_PREF";
 public static final String key01 = "key01";
 public static final String key02 = "key02";
 public static final String key03 = "key03";

 // 加入以下的  constant
 public static final int  MODE_WORLD_WRITTABLE = 0;

 private EditText EditText01;
 private EditText EditText02;
 private EditText EditText03;

 // 多加入一個 button 宣告
 private Button bt;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
       
      // 取出所有元件 
EditText01 = (EditText) findViewById(R.id.editText1);
EditText02 = (EditText) findViewById(R.id.editText2);
EditText03 = (EditText) findViewById(R.id.editText3);
bt  = (Button) findViewById(R.id.button1);
// 由  SharedPreferencs 取出內容,
SharedPreferences st = getSharedPreferences(PREF_NAME,0);
String value01 = st.getString(key01, "");
String value02 = st.getString(key02, "");
String value03 = st.getString(key03, "");

// Assigne 至  EditText 內
EditText01.setText(value01);
EditText02.setText(value02);
EditText03.setText(value03);
       
// button 指定 OnClickListener
// 背下這個語法
bt.setOnClickListener(new Button.OnClickListener()
{
 // 沒有  @Override
 // 記得用  public void
 public void onClick(View v)
 {
  finish();
 }

}
);
      
    }

  
    // 記得用  @Override
    // 得要用  protected void
    // 同時要作 super.onStop();
    @Override
 protected void onStop() {
   
     super.onStop();
     SharedPreferences st = getSharedPreferences(PREF_NAME,MODE_WORLD_WRITTABLE);
   
     SharedPreferences.Editor editor = st.edit();
   
     editor.putString(key01, "" + EditText01.getText());
     editor.putString(key02, "" + EditText02.getText());
     editor.putString(key03, "" + EditText03.getText());
     editor.commit();
 }
}