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/cache
File 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();
    }
}