android可行代码小记

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创建sdcard：在cmd命令行进入android-sdk安装目录下的tools文件夹下，再输入类似代码：mksdcard -l sdcard 200M d:/android/tools/mysdcard/sdcard.img

一.activity中代码

获取sdcard路径：android.os.Environment.getExternalStorageDirectory().getAbsolutePath();

1.oncreat方法部分可重用代码：

记得先声明private Button startGameButton = null;

setContentView(R.layout.main);//设置布局
startGameButton = (Button)findViewById(R.id.startGameButton);//设置按钮组件

startGameButton.setOnClickListener(new startGameButtonListener());//设置监听

class startGameButtonListener implements OnClickListener{//编写触摸监听类

  @Override
  public void onClick(View v) {
   // TODO Auto-generated method stub
   Intent intent = new Intent(); //调用别的activity方法
   intent.putExtra("startGameMode", "1");

//第一个activity-StartChildToyRead转为第二个activity-ChildToyReadActivity
intent.setClass(StartChildToyRead.this, ChildToyReadActivity.class);

StartChildToyRead.this.startActivity(intent);
}
}

2.消息机制

public void creatMessage(String message){
    System.out.println("得到消息:"+message);
    Looper looper = Looper.myLooper();
  MyHandler mHandler = new MyHandler(looper);
    mHandler.removeMessages(0);
    Message m = mHandler.obtainMessage(1, 1, 1, message);
    mHandler.sendMessage(m);
    }

private class MyHandler extends Handler {
  public MyHandler(Looper looper) {
   super(looper);
  }

  @Override
  public void handleMessage(Message msg) { //编写一系列接受到消息msg后的处理
   // TODO Auto-generated method stub
   super.handleMessage(msg);
   String m = msg.obj.toString();
   if (m.equals("begin")) {
    conf = new Configure();
    interf = new HttpInterface();
    initDataBindings init = new initDataBindings(DlgDownload.this,
      interf);
    init.start();
   } else if (m.equals("end")) {
    edlButton.setVisibility(View.VISIBLE);
   }
  }
}

3.音频播放

public static void Play(String path) throws Exception{
    MediaPlayer mp = null;
  mp = new MediaPlayer();
  mp.setDataSource(path);
  mp.prepare();
  mp.start();
  mp.setOnCompletionListener(new OnCompletionListener(){     此处可用消息机制，这样后面的while循环可以省略
            @Override
            public void onCompletion(MediaPlayer mp) {

mp.release();

}

         });
  while(mp.isPlaying()){}
    }

4.AlertDialog.Builder组件使用方法

AlertDialog.Builder builder = new AlertDialog.Builder(类名.this);

builder.setTitle("警告").setIcon(R.drawable.ic_launcher).
setCancelable(false).setMessage("您选择的路径不对，缺少相关文件").setNegativeButton("确定", new OKButton());
dialog = builder.show();

class OKButton implements DialogInterface.OnClickListener{

  @Override
  public void onClick(DialogInterface dialog, int which) {
   // TODO Auto-generated method stub
   dialog.dismiss();
  }
}

5.关闭AlertDialog.Builder方法

AlertDialog.Builder builder = new AlertDialog.Builder(this);
Dialog dialog = builder.show();
dialog.dismiss();

二.布局文件一些代码

1.组件不可见

在布局文件中添加：android:visibility="gone"

要显示，在activity中运行：组件名.setVisibility(View.VISIBLE);

2.组件的排列

android:orientation="horizontal"//横向

android:orientation="vertical"//纵向

3.组件的标示

android:checked="true"设置RadioButton被选中

android:layout_width="30dp"设置宽度，也即对EditText定长度

android:maxLength="4"用于设置EditText输入字符长度

<requestFocus />强制在EditText中显示输入光标

三.AndroidManifest.xml中相关内容

1.文件下载到sdcard，及读写sdcard文件，记得在AndroidManifest.xml中添加权限

<uses-permission android:name="android.permission.INTERNET" />

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>

2.申明主activity次activity实例

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity             //次activity
            android:screenOrientation="landscape"
            android:name=".ttsDemo"
            android:label="@string/tts"
            android:theme="@android:style/Theme.Dialog"/>   //小窗口显示activity
        <activity             //次activity
            android:name=".DownLoadStory"
            android:label="@string/sg"
        />
     </application>

四.java调试用语句：

写日志：例如hwano.util.file.Log.printError("text","c:\\jilu\\text.txt");