轻巧级记事本的开发

      今天按计划没什么大事，所以去学习制作了一下记事本，有三种功能，可以添加文字、图文、视频+文字，还有删除功能。源码下载地址：http://download.csdn.net/detail/sdksdk0/9338679。

  首先看到MainActivity:

初始化界面

public void initView() {
		lv = (ListView) findViewById(R.id.list);
		textbtn = (Button) findViewById(R.id.text);
		imgbtn = (Button) findViewById(R.id.img);
		videobtn = (Button) findViewById(R.id.video);
		textbtn.setOnClickListener(this);
		imgbtn.setOnClickListener(this);
		videobtn.setOnClickListener(this);
		notesDB = new NoteDB(this);
		dbReader = notesDB.getReadableDatabase();
		lv.setOnItemClickListener(new OnItemClickListener() {

			@Override
			public void onItemClick(AdapterView<?> parent, View view,
					int position, long id) {
				cursor.moveToPosition(position);
				Intent i = new Intent(MainActivity.this, SelectAct.class);
				i.putExtra(NoteDB.ID,
						cursor.getInt(cursor.getColumnIndex(NoteDB.ID)));
				i.putExtra(NoteDB.CONTENT, cursor.getString(cursor
						.getColumnIndex(NoteDB.CONTENT)));
				i.putExtra(NoteDB.TIME,
						cursor.getString(cursor.getColumnIndex(NoteDB.TIME)));
				i.putExtra(NoteDB.PATH,
						cursor.getString(cursor.getColumnIndex(NoteDB.PATH)));
				i.putExtra(NoteDB.VIDEO,
						cursor.getString(cursor.getColumnIndex(NoteDB.VIDEO)));
				startActivity(i);
			}
		});
	}

三个按钮的点击，用1-3来表示三个按钮的响应code。

@Override
	public void onClick(View v) {
		i = new Intent(this, AddContent.class);
		switch (v.getId()) {
		case R.id.text:
			i.putExtra("flag", "1");
			startActivity(i);
			break;

		case R.id.img:
			i.putExtra("flag", "2");
			startActivity(i);
			break;

		case R.id.video:
			i.putExtra("flag", "3");
			startActivity(i);
			break;
		}
	}

在MyAdapter.java中，

获取文本内容：

public View getView(int position, View convertView, ViewGroup parent) {

		LayoutInflater inflater = LayoutInflater.from(context);
		layout = (LinearLayout) inflater.inflate(R.layout.cell, null);
		TextView contenttv = (TextView) layout.findViewById(R.id.list_content);
		TextView timetv = (TextView) layout.findViewById(R.id.list_time);
		ImageView imgiv = (ImageView) layout.findViewById(R.id.list_img);
		ImageView videoiv = (ImageView) layout.findViewById(R.id.list_video);
		cursor.moveToPosition(position);
		String content = cursor.getString(cursor.getColumnIndex("content"));
		String time = cursor.getString(cursor.getColumnIndex("time"));
		String url = cursor.getString(cursor.getColumnIndex("path"));
		String urlvideo = cursor.getString(cursor.getColumnIndex("video"));
		contenttv.setText(content);
		timetv.setText(time);
		videoiv.setImageBitmap(getVideoThumbnail(urlvideo, 200, 200,
				MediaStore.Images.Thumbnails.MICRO_KIND));
		imgiv.setImageBitmap(getImageThumbnail(url, 200, 200));
		return layout;
	}

得到拍照后图片的缩略图

public Bitmap getImageThumbnail(String uri, int width, int height) {
		Bitmap bitmap = null;
		BitmapFactory.Options options = new BitmapFactory.Options();
		options.inJustDecodeBounds = true;
		bitmap = BitmapFactory.decodeFile(uri, options);
		options.inJustDecodeBounds = false;
		int beWidth = options.outWidth / width;
		int beHeight = options.outHeight / height;
		int be = 1;
		if (beWidth < beHeight) {
			be = beWidth;
		} else {
			be = beHeight;
		}
		if (be <= 0) {
			be = 1;
		}
		options.inSampleSize = be;
		bitmap = BitmapFactory.decodeFile(uri, options);
		bitmap = ThumbnailUtils.extractThumbnail(bitmap, width, height,
				ThumbnailUtils.OPTIONS_RECYCLE_INPUT);
		return bitmap;
	}

得到摄像的视频的缩略图：

private Bitmap getVideoThumbnail(String uri, int width, int height, int kind) {
		Bitmap bitmap = null;
		bitmap = ThumbnailUtils.createVideoThumbnail(uri, kind);
		bitmap = ThumbnailUtils.extractThumbnail(bitmap, width, height,
				ThumbnailUtils.OPTIONS_RECYCLE_INPUT);

		return bitmap;
	}

在Select.java中：

删除功能：

if (getIntent().getStringExtra(NoteDB.PATH).equals("null")) {
			s_img.setVisibility(View.GONE);
		} else {
			s_img.setVisibility(View.VISIBLE);
		}
		if (getIntent().getStringExtra(NoteDB.VIDEO).equals("null")) {
			s_video.setVisibility(View.GONE);
		} else {
			s_video.setVisibility(View.VISIBLE);
		}

删除写的内容

public void deleteDate() {
		dbWriter.delete(NoteDB.TABLE_NAME,
				"_id=" + getIntent().getIntExtra(NoteDB.ID, 0), null);
	}

之后还有一些返回结果之内的东西，这里就不一一说明了，布局文件可以去看源码。记得在清单文件中添加权限哦！