安卓小案例收集一

收集一

电话拨号

    //1.创建意图    Intent intent = new Intent();    //2.把动作封装至意图中    intent.setAction(Intent.ACTION_CALL);    //3.打电话打给谁    intent.setData(Uri.parse("tel:" + number));    //4.告诉系统，我的动作    startActivity(intent);

点击事件的几种触发方式

//第一种bt_iq.setOnClickListener(new OnClickListener() {            //v：触发该方法执行的组件对象            @Override            public void onClick(View v) {                System.out.println("智商已-10");            }        });//第二种public void click1(View v){        //获取组件的资源id        int id = v.getId();        switch (id) {        case R.id.bt1:            System.out.println("按钮1");            break;        case R.id.bt2:            System.out.println("按钮2");            break;        case R.id.bt3:            System.out.println("按钮3");            break;        }    }//第三种，实现OnclickListener的接口

发送短信：

    //直接使用发送短信的api，无需启动系统的短信应用    SmsManager sm = SmsManager.getDefault();        //把长短信截成若干条短短信    ArrayList<String> sms = sm.divideMessage(content);          for (String string : sms) {             //arg0:目标号码        //arg1:短信中心号码，null表示使用默认        //arg2:短信正文        sm.sendTextMessage(phone, null, string, null, null);    }      }

读写内存文件

//写//返回一个File对象，封装的路径是data/data/com.itheima.rwinrom/cacheFile file = new File(getCacheDir(), "info.txt");try {    FileOutputStream fos = new FileOutputStream(file);    //把账号密码写入本地文件    fos.write((name + "&&" + pass).getBytes());    fos.close();    } catch (Exception e) {    // TODO Auto-generated catch block    e.printStackTrace();}//读File file = new File(getCacheDir(), "info.txt");if(file.exists()){    try {        FileInputStream fis = new FileInputStream(file);        //把字节流转换成字符流        BufferedReader br = new BufferedReader(new InputStreamReader(fis));        //读取文件中的文本        String text = br.readLine();        String s[] = text.split("&&");        //给输入框设置文本        et_name.setText(s[0]);        et_pass.setText(s[1]);    } catch (Exception e) {        // TODO Auto-generated catch block        e.printStackTrace();    }}

读写外存（sd卡）

写

public void login(View v){    //获取用户输入的账号密码    String name = et_name.getText().toString();    String pass = et_pass.getText().toString();    CheckBox cb = (CheckBox) findViewById(R.id.cb);    //判断选框是否选中    if(cb.isChecked()){//          File file = new File("sdcard/info.txt");        //MEDIA_REMOVED：sd卡不存在        //MEDIA_UNMOUNTED：sd卡存在，但是没有挂载        //MEDIA_CHECKING：sd卡正在遍历        //MEDIA_MOUNTED：sd卡可用        //MEDIA_MOUNTED_READ_ONLY：sd卡可用，但是只读        if(Environment.getExternalStorageState().equals(Environment.MEDIA_MOUNTED)){            //返回一个File对象，封装了外部存储的真实路径            File file = new File(Environment.getExternalStorageDirectory(), "info.txt");            try {                FileOutputStream fos = new FileOutputStream(file);                //把账号密码写入本地文件                fos.write((name + "&&" + pass).getBytes());                fos.close();            } catch (Exception e) {                // TODO Auto-generated catch block                e.printStackTrace();            }        }        else{            Toast.makeText(this, "SD卡不可用哟亲(づ￣ 3￣づ", 0).show();        }    }//      System.out.println("登录成功");    //创建吐司对话框    Toast t = Toast.makeText(this, "登录成功", 0);    //显示对话框    t.show();   }

读

private void readAccount() {//      File file = new File("sdcard/info.txt");    File file = new File(Environment.getExternalStorageDirectory(), "info.txt");    if(file.exists()){        try {            FileInputStream fis = new FileInputStream(file);            //把字节流转换成字符流            BufferedReader br = new BufferedReader(new InputStreamReader(fis));            //读取文件中的文本            String text = br.readLine();                    String s[] = text.split("&&");              //给输入框设置文本            et_name.setText(s[0]);            et_pass.setText(s[1]);        } catch (Exception e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }}

获取SD卡剩余容量

protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    File path = Environment.getExternalStorageDirectory();    StatFs stat = new StatFs(path.getPath());    long blockSize;    long totalBlocks;    long availableBlocks;    //判断当前版本是否是4.3或以上    if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN_MR2){         blockSize = stat.getBlockSizeLong();         totalBlocks = stat.getBlockCountLong();         availableBlocks = stat.getAvailableBlocksLong();    }    else{         blockSize = stat.getBlockSize();         totalBlocks = stat.getBlockCount();         availableBlocks = stat.getAvailableBlocks();    }           String text = formatSize(availableBlocks * blockSize);    TextView tv = (TextView) findViewById(R.id.tv);     tv.setText(text);}private String formatSize(long size) {       return Formatter.formatFileSize(this, size);}

设置文件访问权限

可读可写权限已经过时，官方不推荐

public void click1(View v){        //路径默认为data/data/com.itheima.permission/files        try {            FileOutputStream fos = openFileOutput("info1.txt", MODE_PRIVATE);            fos.write("hahaha".getBytes());        } catch (Exception e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }    public void click2(View v){        //路径默认为data/data/com.itheima.permission/files        try {            @SuppressWarnings("deprecation")            FileOutputStream fos = openFileOutput("info2.txt", MODE_WORLD_READABLE);            fos.write("lalala".getBytes());        } catch (Exception e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }    public void click3(View v){        //路径默认为data/data/com.itheima.permission/files        try {            @SuppressWarnings("deprecation")            FileOutputStream fos = openFileOutput("info3.txt", MODE_WORLD_WRITEABLE | MODE_WORLD_READABLE);            fos.write("ohohohohoho".getBytes());        } catch (Exception e) {            // TODO Auto-generated catch block            e.printStackTrace();        }    }

SharedPreference一个保存数据的对象

private void readAccount() {        //获取sharedpreference        SharedPreferences sp = getSharedPreferences("info", MODE_PRIVATE);         String name = sp.getString("name", "");        String pass = sp.getString("pass", "");        et_name.setText(name);        et_pass.setText(pass);    }    public void login(View v){        //获取用户输入的账号密码        String name = et_name.getText().toString();        String pass = et_pass.getText().toString();        CheckBox cb = (CheckBox) findViewById(R.id.cb);        //判断选框是否选中        if(cb.isChecked()){            //获取sharedpreference            SharedPreferences sp = getSharedPreferences("info", MODE_PRIVATE);             //获取编辑器            Editor ed = sp.edit();            ed.putString("name", name);            ed.putString("pass", pass);            //提交            ed.commit();        }        //创建吐司对话框        Toast t = Toast.makeText(this, "登录成功", 0);        //显示对话框        t.show();    }

生成XML文件

//sms是自定义类public void click(View v){    //获取xml序列化器    XmlSerializer xs = Xml.newSerializer();    File file = new File("sdcard/sms2.xml");    FileOutputStream fos;    try {        fos = new FileOutputStream(file);        //初始化        //xml文件中什么编码生成        xs.setOutput(fos, "utf-8");        //开始生成xml文件        //生成头结点        xs.startDocument("utf-8", true);        //生成开始标签        xs.startTag(null, "smss");        for (Sms sms : smsList) {            xs.startTag(null, "sms");                       xs.startTag(null, "body");            xs.text(sms.getBody() + "<body>");            xs.endTag(null, "body");                        xs.startTag(null, "type");            xs.text(sms.getType() + "");            xs.endTag(null, "type");            xs.startTag(null, "date");            xs.text(sms.getDate() + "");            xs.endTag(null, "date");            xs.startTag(null, "address");            xs.text(sms.getAddress());            xs.endTag(null, "address");            xs.endTag(null, "sms");        }               //生成结束标签        xs.endTag(null, "smss");                //告知序列化器生成xml结束        xs.endDocument();    } catch (Exception e) {        // TODO Auto-generated catch block        e.printStackTrace();    }}

XML解析

public void click(View v){    //获取天气信息xml文件    InputStream is = getClassLoader().getResourceAsStream("weather.xml");    //获取xmlpull解析器    XmlPullParser xp = Xml.newPullParser();    try {        //初始化        xp.setInput(is, "gbk");        //获取当前节点的事件类型        int type = xp.getEventType();        City city = null;        while(type != XmlPullParser.END_DOCUMENT){            switch (type) {            case XmlPullParser.START_TAG:                                //获取当前节点的名字                if("weather".equals(xp.getName())){                    cityList = new ArrayList<City>();                }                else if("city".equals(xp.getName())){                    city = new City();                }                else if("name".equals(xp.getName())){                                    //获取下一个节点的文本                    String name = xp.nextText();                    city.setName(name);                }                else if("temp".equals(xp.getName())){                    //获取下一个节点的文本，把指针移动至当前节点的结束节点                    String temp = xp.nextText();                    city.setTemp(temp);                }                else if("pm25".equals(xp.getName())){                    //获取下一个节点的文本                    String pm25 = xp.nextText();                    city.setPm25(pm25);                }                break;            case XmlPullParser.END_TAG:                if("city".equals(xp.getName())){                    cityList.add(city);                }                break;            }            //把指针移动至下一个节点，并返回该节点的事件类型            type = xp.next();        }    } catch (Exception e) {        // TODO Auto-generated catch block        e.printStackTrace();    }    for (City city : cityList) {        System.out.println(city.toString());    }}

测试类写法

权限

<instrumentation         android:name="android.test.InstrumentationTestRunner"        android:targetPackage="com.itheima.junit"></instrumentation>

test类代码：

public class Test extends AndroidTestCase {    public void test(){        int result = Tools.damage(8, 5);        //断言：检测预期和实际结果是否一致        assertEquals(3, result);    }    public void test2(){        Tools.showTeXiao();    }}