个人android笔记(三)

1、代码片段：获得最新通话记录的时长,格式为HH:mm:ss

public String getFormattedTime() {
		long duration = 0;
		Cursor cursor = getContentResolver().query(CallLog.Calls.CONTENT_URI,
				new String[] { CallLog.Calls.DURATION }, null, null,
				CallLog.Calls.DEFAULT_SORT_ORDER);

		if (cursor != null) {
			cursor.moveToPosition(0);//最新的一条
			duration = cursor.getLong(0);
		}
		String pattern = "mm:ss";
		if (duration > 3600) {
			pattern = "HH:mm:ss";
		}
		SimpleDateFormat format = new SimpleDateFormat(pattern);
		return format.format(new Date((long) duration * 1000));
	}

2、颜色的使用。
在android是可以是使用Android.Graphics.Color类的Color.BLACK、Color.RED等来设置颜色的，但这样的做法，不符合MVC将模块与资源分开的思想，故强烈建议使用在res/values/color.xml中定义color变量

<resources>
    <color name="my_red">#00ffff00</color>
</resources>

然后引用

int color = getResources().getColor(R.color.my_red);
tv.setColor(color);

3、gallery简单应用：

private Gallery gallery;
	private int[] myImage = {android.R.drawable.alert_dark_frame,
							android.R.drawable.arrow_up_float,
							android.R.drawable.btn_default_small,
							android.R.drawable.checkbox_on_background};
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		// TODO Auto-generated method stub
		super.onCreate(savedInstanceState);
		setContentView(R.layout.ch3_15);
		gallery = (Gallery)findViewById(R.id.ch3_15_gallery);
		gallery.setAdapter(new ImageAdapter(this));		
	}
	
	private class ImageAdapter extends BaseAdapter{
		Context context;
		public ImageAdapter(Context context){
			this.context = context;
		}
		@Override
		public int getCount() {
			// TODO Auto-generated method stub
			return myImage.length;
		}
		@Override
		public Object getItem(int position) {
			// TODO Auto-generated method stub
			return position;
		}
		@Override
		public long getItemId(int position) {
			// TODO Auto-generated method stub
			return position;
		}
		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			// TODO Auto-generated method stub
			ImageView iv = new ImageView(this.context);
			iv.setImageResource(myImage[position]);
			iv.setScaleType(ImageView.ScaleType.FIT_XY);
			iv.setLayoutParams(new Gallery.LayoutParams(120,120));
			return iv;
			
		}
		
	}