练手小项目（5）安全卫士_利用内容提供者进行短信备份

通过点击button来备份短信  索性直接写成工具类得了

①第一点 初始化布局 Initview(context);

private static void Initview(Context context) {pd = new ProgressDialog(context);pd.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);pd.setMessage("正在备份数据");pd.show();}

②得到一个SD卡路径进行读取，因为要按照一定的格式写入，所以使用XML  注意加权限

File file = new File(Environment.getExternalStorageDirectory(),"backup.xml");FileOutputStream fos = new FileOutputStream(file);

③ 通过内容提供者得到 短信的发件人 内容 类型 ，日期

ContentResolver resolver = context.getContentResolver();Uri uri = Uri.parse("content://sms/");Cursor cursor = resolver.query(uri, new String[] { "body", "address","type", "date" }, null, null, null);

④通过pull解析组装xml 输出到SD卡中

XmlSerializer serializer = Xml.newSerializer();// 初始化生成器serializer.setOutput(fos, "utf-8");serializer.startDocument("utf-8", true);serializer.startTag(null, "smss");serializer.attribute(null, "max", max + "");int process = 0;while (cursor.moveToNext()) {Thread.sleep(500);String body = cursor.getString(0);String address = cursor.getString(1);String type = cursor.getString(2);String date = cursor.getString(3);serializer.startTag(null, "sms");serializer.startTag(null, "body");serializer.text(body);serializer.endTag(null, "body");serializer.startTag(null, "address");serializer.text(address);serializer.endTag(null, "address");serializer.startTag(null, "type");serializer.text(type);serializer.endTag(null, "type");serializer.startTag(null, "date");serializer.text(date);serializer.endTag(null, "date");serializer.endTag(null, "sms");// 备份过程中，增加进度process++;// pb.setProgress(process);pd.setProgress(process);}cursor.close();serializer.endTag(null, "smss");serializer.endDocument();fos.close();// pd.dismiss();}

在 activity中掉用 也简单

@Overridepublic void onClick(View v) {try {SmsUtils.backupSms(this);Toast.makeText(SmsActivity.this, "备份成功", Toast.LENGTH_SHORT);} catch (Exception e) {Toast.makeText(SmsActivity.this, "备份失败", Toast.LENGTH_SHORT);e.printStackTrace();}}

这一节不是很好,有点小bug，在下一节  我将用接口回调解耦