Android之使用RatingBar設置遊戲難度並保存 – Android移動開發技術文章_手機開發 Android移動開發教學課程

最近在學習遊戲開發，在遊戲中常常需要設置遊戲的難度，在Android中我們可以使用RatingBar來實現。具體看下面的代碼：

效果圖如下：

package com.cloay.pt.ui; 
 
import java.io.FileNotFoundException; 
import java.io.IOException; 
 
import android.content.ContentResolver; 
import android.content.Intent; 
import android.content.SharedPreferences; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.net.Uri; 
import android.os.Bundle; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.ImageView; 
import android.widget.RatingBar; 
import android.widget.RatingBar.OnRatingBarChangeListener; 
import android.widget.TextView; 
 
import com.cloay.pt.BasicActivity; 
import com.cloay.pt.R; 
import com.cloay.pt.constants.Constant; 
import com.cloay.pt.utils.ImageUtil; 
 
/**
 * 遊戲設置類,遊戲難度等
 * @author Cloay
 * 2011-12-23
 * 下午05:21:41
 */ 
public class SettingsActivity extends BasicActivity{ 
    private SharedPreferences settings;  //保存設置  
    private RatingBar ratingBar; 
    private TextView defaultPicture; 
    private TextView picture; 
    private ImageView previewImage; 
    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
        super.onCreate(savedInstanceState); 
        setContentView(R.layout.settings); 
        BasicActivity.allActivity.add(this); 
        //初始化數據  
        initData(); 
    } 
     
    /**
     * 初始化數據
     */ 
    private void initData() { 
        settings = getSharedPreferences("settings", 0); 
        ratingBar = (RatingBar) findViewById(R.id.rating); 
        //遊戲默認圖片  
        defaultPicture = (TextView) findViewById(R.id.def); 
        //從圖庫中選擇圖片，自定義  
        picture = (TextView) findViewById(R.id.picture); 
        previewImage = (ImageView)findViewById(R.id.preview); 
        if("".equals(settings.getString("picture", ""))) { 
            previewImage.setImageResource(R.drawable.def); 
        }else{ 
            previewImage.setImageBitmap(ImageUtil.getBitmapFromSDCard(settings.getString("picture", ""))); 
        } 
        //設置難度選擇監聽  
        ratingBar.setOnRatingBarChangeListener(new OnRatingBarChangeListener() { 
            @Override 
            public void onRatingChanged(RatingBar ratingBar, float rating, 
                    boolean fromUser) { 
                settings.edit().putInt("level", (int)rating).commit();   //保存用戶設置後的遊戲難度  
                showToast(SettingsActivity.this, (int)rating); 
            } 
        }); 
        //設置圖片選擇監聽  
        defaultPicture.setOnClickListener(new OnClickListener() { 
            @Override 
            public void onClick(View v) { 
                settings.edit().putString("picture", "").commit(); 
                previewImage.setImageResource(R.drawable.def); 
            } 
        }); 
        picture.setOnClickListener(new OnClickListener() { 
            @Override 
            public void onClick(View v) { 
                Intent intent = new Intent();   
                /* 開啟Pictures畫面Type設定為image */   
                intent.setType("image/*");   
                /* 使用Intent.ACTION_GET_CONTENT這個Action */   
                intent.setAction(Intent.ACTION_GET_CONTENT);  
                /* 取得相片後返回本畫面 */   
                startActivityForResult(intent, 1); 
            } 
        }); 
         
    } 
     
    @Override 
    protected void onActivityResult(int requestCode, int resultCode, Intent data) { 
        if (resultCode == RESULT_OK) {   
            Uri uri = data.getData();   
            ContentResolver cr = this.getContentResolver();   
            try {   
                Bitmap bitmap = BitmapFactory.decodeStream(cr.openInputStream(uri));   
                try { 
                    saveBitmap("cloay", bitmap); 
                } catch (IOException e) { 
                    e.printStackTrace(); 
                } 
                settings.edit().putString("picture", Constant.picPath + "cloay.png").commit(); 
                previewImage.setImageBitmap(bitmap); 
            } catch (FileNotFoundException e) {   
                settings.edit().putString("picture", "").commit(); 
                previewImage.setImageResource(R.drawable.def); 
            }   
        }  
        super.onActivityResult(requestCode, resultCode, data); 
    } 
} 
package com.cloay.pt.ui;

import java.io.FileNotFoundException;
import java.io.IOException;

import android.content.ContentResolver;
import android.content.Intent;
import android.content.SharedPreferences;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ImageView;
import android.widget.RatingBar;
import android.widget.RatingBar.OnRatingBarChangeListener;
import android.widget.TextView;

import com.cloay.pt.BasicActivity;
import com.cloay.pt.R;
import com.cloay.pt.constants.Constant;
import com.cloay.pt.utils.ImageUtil;

/**
 * 遊戲設置類,遊戲難度等
 * @author Cloay
 * 2011-12-23
 * 下午05:21:41
 */
public class SettingsActivity extends BasicActivity{
 private SharedPreferences settings;  //保存設置
 private RatingBar ratingBar;
 private TextView defaultPicture;
 private TextView picture;
 private ImageView previewImage;
 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.settings);
  BasicActivity.allActivity.add(this);
  //初始化數據
  initData();
 }
 
 /**
  * 初始化數據
  */
 private void initData() {
  settings = getSharedPreferences("settings", 0);
  ratingBar = (RatingBar) findViewById(R.id.rating);
  //遊戲默認圖片
  defaultPicture = (TextView) findViewById(R.id.def);
  //從圖庫中選擇圖片，自定義
  picture = (TextView) findViewById(R.id.picture);
  previewImage = (ImageView)findViewById(R.id.preview);
  if("".equals(settings.getString("picture", ""))) {
   previewImage.setImageResource(R.drawable.def);
  }else{
   previewImage.setImageBitmap(ImageUtil.getBitmapFromSDCard(settings.getString("picture", "")));
  }
  //設置難度選擇監聽
  ratingBar.setOnRatingBarChangeListener(new OnRatingBarChangeListener() {
   @Override
   public void onRatingChanged(RatingBar ratingBar, float rating,
     boolean fromUser) {
    settings.edit().putInt("level", (int)rating).commit();   //保存用戶設置後的遊戲難度
    showToast(SettingsActivity.this, (int)rating);
   }
  });
  //設置圖片選擇監聽
  defaultPicture.setOnClickListener(new OnClickListener() {
   @Override
   public void onClick(View v) {
    settings.edit().putString("picture", "").commit();
    previewImage.setImageResource(R.drawable.def);
   }
  });
  picture.setOnClickListener(new OnClickListener() {
   @Override
   public void onClick(View v) {
    Intent intent = new Intent(); 
                /* 開啟Pictures畫面Type設定為image */ 
                intent.setType("image/*"); 
                /* 使用Intent.ACTION_GET_CONTENT這個Action */ 
                intent.setAction(Intent.ACTION_GET_CONTENT);
                /* 取得相片後返回本畫面 */ 
                startActivityForResult(intent, 1);
   }
  });
  
 }
 
 @Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
  if (resultCode == RESULT_OK) { 
            Uri uri = data.getData(); 
            ContentResolver cr = this.getContentResolver(); 
            try { 
                Bitmap bitmap = BitmapFactory.decodeStream(cr.openInputStream(uri)); 
                try {
     saveBitmap("cloay", bitmap);
    } catch (IOException e) {
     e.printStackTrace();
    }
    settings.edit().putString("picture", Constant.picPath + "cloay.png").commit();
    previewImage.setImageBitmap(bitmap);
            } catch (FileNotFoundException e) { 
             settings.edit().putString("picture", "").commit();
             previewImage.setImageResource(R.drawable.def);
            } 
        }
  super.onActivityResult(requestCode, resultCode, data);
 }
}

通過設置setOnRatingBarChangeListener監聽器來獲取用戶選擇RatingBar的值，獲取之後往往需要保存，通常使用SharedPrefence即可，也可選用SQLite等。SharedPrefence的使用詳細請看: Android SharedPreferences的使用/kf/201203/125000.html 
 

摘自  Cloay的專欄