无废话Android之smartimageview使用、android多线程下载、显式意图激活另外一个activity,检查网络是否可用定位到网络的位置、隐式意图激活另外一个activity、隐式意图的配置，自定义隐式意图、在不同activity之间数据传递（5）

1.smartimageview使用

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:orientation="vertical"

    tools:context=".MainActivity" >

    <com.loopj.android.image.SmartImageView

        android:id="@+id/iv_beauty"

        android:layout_width="match_parent"

        android:layout_height="match_parent"

        android:layout_weight="100" />

    <EditText

        android:id="@+id/et_path"

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:singleLine="true"

        android:text="http://a.hiphotos.baidu.com/album/w%3D2048/sign=0a938b00d53f8794d3ff4f2ee6230cf4/faedab64034f78f06fe0f24b78310a55b2191c9a.jpg" />

    <Button

        android:layout_width="match_parent"

        android:layout_height="wrap_content"

        android:onClick="watch"

        android:text="浏览" />

</LinearLayout>

public class MainActivity extends Activity {

private EditText et_path;

@Override

protected void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

this.et_path = (EditText) this.findViewById(R.id.et_path);

}

public void watch(View view) {

String url = this.et_path.getText().toString().trim();

SmartImageView siv = (SmartImageView) this.findViewById(R.id.iv_beauty);

siv.setImageUrl(url, R.drawable.ic_launcher, R.drawable.ic_launcher);

}

}

<uses-permission android:name="android.permission.INTERNET"/>

2.android多线程下载

public class MainActivity extends Activity {

    protected static final int SERVER_ERROR = 1;

    protected static final int DOWN_LOAD_ERROR = 2;

    protected static final int DOWN_LOAD_SUCCESS = 3;

    protected static final int UPDATE_TEXT = 4;

    private EditText et_path;

    private ProgressBar pb_download;

    private TextView tv_process;

    private static int threadCount = 3;

    private static int runningThread = threadCount;

    private static int currentProgress = 0;

    private static String resource = "/mnt/sdcard/oracle.pptx";

    private static String path = "http://110.65.99.66:8080/oracle.pptx";

    private static String mode = "rwd";

    private Handler handler = new Handler() {

        @Override

        public void handleMessage(Message msg) {

            switch (msg.what) {

            case SERVER_ERROR:

                Toast.makeText(MainActivity.this,

                        "服务器错误，错误码：" + (String) msg.obj, 0).show();

                break;

            case DOWN_LOAD_ERROR:

                Toast.makeText(MainActivity.this, "下载失败", 0).show();

                break;

            case DOWN_LOAD_SUCCESS:

                Toast.makeText(MainActivity.this, "文件下载完毕，临时文件被删除!", 0).show();

                break;

            case UPDATE_TEXT:

                tv_process.setText("当前进度：" + pb_download.getProgress() * 100

                        / pb_download.getMax());

                break;

            }

        }

    };

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        this.et_path = (EditText) this.findViewById(R.id.et_path);

        this.pb_download = (ProgressBar) this.findViewById(R.id.pb_download);

        this.tv_process = (TextView) this.findViewById(R.id.tv_process);

    }

    public void download(View view) {

        new Thread() {

            public void run() {

                try {

                    // 连接服务器获取一个文件，在本地创建一个和它相同大小的临时文件

                    URL url = new URL(path);

                    HttpURLConnection conn = (HttpURLConnection) url

                            .openConnection();

                    conn.setRequestMethod("GET");

                    conn.setConnectTimeout(5000);

                    int code = conn.getResponseCode();

                    if (code == 200) {

                        // 服务器返回的数据长度，实际上就是文件的长度

                        int length = conn.getContentLength();

                        System.out.println("文件的长度 ：" + length);

                        // 设置进度条的最大值

                        pb_download.setMax(length - 1);

                        // 在本地创建一个大小跟服务器文件一样大小的临时文件

                        RandomAccessFile raf = new RandomAccessFile(resource,

                                mode);

                        // 指定文件的长度

                        raf.setLength(length);

                        raf.close();

                        // 假设是3个线程去下载资源

                        // 计算平均每个线程下载的文件大小

                        int blockSize = length / threadCount;

                        // 标记正在运行子线程的个数

                        runningThread = threadCount;

                        // 下载进度归零

                        currentProgress = 0;

                        // 下载进度条归零

                        pb_download.setProgress(0);

                        System.out.println("blockSize = " + blockSize);

                        for (int threadId = 1; threadId <= threadCount; threadId++) {

                            // 线程的开始和结束位置

                            int startIndex = (threadId - 1) * blockSize;

                            int endIndex = threadId * blockSize - 1;

                            if (threadId == threadCount) {

                                endIndex = length - 1;

                            }

                            System.out.println("线程：" + threadId + "下载："

                                    + startIndex + "--->" + endIndex);

                            new DownLoadThread(threadId, startIndex, endIndex,

                                    path).start();

                        }

                    } else {

                        Message msg = new Message();

                        msg.what = SERVER_ERROR;

                        msg.obj = code + "";

                        handler.sendMessage(msg);

                    }

                } catch (Exception e) {

                    e.printStackTrace();

                    Message msg = new Message();

                    msg.what = DOWN_LOAD_ERROR;

                    handler.sendMessage(msg);

                }

            };

        }.start();

    }

    public class DownLoadThread extends Thread {

        private int threadId;

        private int startIndex;

        private int endIndex;

        private String path;

        private String tempFileUrl;

        public DownLoadThread(int threadId, int startIndex, int endIndex,

                String path) {

            this.threadId = threadId;

            this.startIndex = startIndex;

            this.endIndex = endIndex;

            this.path = path;

            tempFileUrl = "/mnt/sdcard/" + threadId + ".txt";

        }

        @Override

        public void run() {

            try {

                // 检查是否存在记录下载长度的文件，如果存在读取这个文件的数据

                File tempFile = new File(tempFileUrl);

                if (tempFile.exists() && tempFile.length() > 0) {

                    FileInputStream fis = new FileInputStream(tempFile);

                    byte[] buffer = new byte[1024];

                    int length = fis.read(buffer);

                    String downloadLength = new String(buffer, 0, length);

                    int downloadLenInt = Integer.parseInt(downloadLength);

                    int alreayDownloadInt = downloadLenInt - startIndex;

                    currentProgress += alreayDownloadInt;// 计算上次断点下载到的进度

                    // 修改下载的真实开始位置

                    startIndex = downloadLenInt;

                    fis.close();

                }

                System.out.println("线程真正开始的位置 ：" + threadId + "下载："

                        + startIndex + "--->" + endIndex);

                URL url = new URL(path);

                HttpURLConnection conn = (HttpURLConnection) url

                        .openConnection();

                conn.setRequestMethod("GET");

                conn.setConnectTimeout(5000);

                // 请求服务器下载部分文件，指定文件的位置

                conn.setRequestProperty("Range", "bytes=" + startIndex + "-"

                        + endIndex);

                conn.setConnectTimeout(60000);

                // 200表示从服务器请求全部资源，206表示从服务器请求部分资源

                int code = conn.getResponseCode();

                if (code == 206) {

                    // 已经设置了请求的位置，返回的是当前文件位置对应的文件的输入流

                    InputStream is = conn.getInputStream();

                    // 此类的实例支持对随机访问文件的读取和写入

                    RandomAccessFile raf = new RandomAccessFile(resource, mode);

                    // 定位文件

                    raf.seek(startIndex);

                    int length = 0;

                    byte[] buffer = new byte[1024];

                    int total = 0;// 实时记录已经下载的长度

                    // 一阵狂读

                    while ((length = is.read(buffer)) != -1) {

                        RandomAccessFile file = new RandomAccessFile(

                                tempFileUrl, mode);

                        raf.write(buffer, 0, length);

                        total += length;

                        // 记录当前线程下载的数据位置

                        file.write((total + startIndex - 1 + "").getBytes());

                        file.close();

                        synchronized (MainActivity.this) {

                            // 获取所有线程下载的总进度

                            currentProgress += length;

                            // 更改界面上progressbar的进度(progressbar和progressdialog可以在子线程里修改UI)

                            pb_download.setProgress(currentProgress);

                            Message msg = Message.obtain();

                            msg.what = UPDATE_TEXT;

                            handler.sendMessage(msg);

                        }

                    }

                    raf.close();

                    is.close();

                    System.out.println("线程 ： " + threadId + "下载完毕。。。。。");

                    runningThread--;

                } else {

                    System.out.println("线程 ： " + threadId + "下载失败。。。。。");

                }

            } catch (Exception e) {

                e.printStackTrace();

                System.out.println("线程 ： " + threadId + "  抛出异常！");

                runningThread = threadCount;

            } finally {

                System.out.println("runningThread = " + runningThread);

                if (runningThread == 0) {

                    for (int i = 1; i <= threadCount; i++) {

                        File deleteFile = new File("/mnt/sdcard/" + i + ".txt");

                        deleteFile.delete();

                    }

                    Message msg = new Message();

                    msg.what = DOWN_LOAD_SUCCESS;

                    handler.sendMessage(msg);

                }

            }

        }

    }

}

3.显式意图激活另外一个activity,检查网络是否可用定位到网络的位置

<intent-filter>

    <action android:name="android.intent.action.MAIN" />

    <category android:name="android.intent.category.LAUNCHER" />

</intent-filter>

这段代码的作用是告诉系统在桌面创建一个快捷图标

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"

    xmlns:tools="http://schemas.android.com/tools"

    android:layout_width="match_parent"

    android:layout_height="match_parent"

    android:paddingBottom="@dimen/activity_vertical_margin"

    android:paddingLeft="@dimen/activity_horizontal_margin"

    android:paddingRight="@dimen/activity_horizontal_margin"

    android:paddingTop="@dimen/activity_vertical_margin"

    tools:context=".MainActivity" >

    <Button

        android:id="@+id/button1"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignParentLeft="true"

        android:layout_alignParentTop="true"

        android:onClick="click1"

        android:text="跳转到第二个界面1" />

    <Button

        android:id="@+id/button2"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignRight="@+id/button1"

        android:layout_below="@+id/button1"

        android:layout_marginTop="24dp"

        android:onClick="click2"

        android:text="跳转到第二个界面2" />

    <Button

        android:id="@+id/button3"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignLeft="@+id/button2"

        android:layout_below="@+id/button2"

        android:layout_marginLeft="44dp"

        android:layout_marginTop="27dp"

        android:onClick="click3"

        android:text="检查手机网络状态" />

    <Button

        android:id="@+id/button4"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignLeft="@+id/button2"

        android:layout_below="@+id/button3"

        android:layout_marginLeft="16dp"

        android:layout_marginTop="37dp"

        android:onClick="click4"

        android:text="跳转到图库" />

</RelativeLayout>

public class MainActivity extends Activity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

    }

    public void click1(View view) {

        Intent intent = new Intent();

        intent.setClassName(this, "com.itheima.explicitintent.SecondActivity");

        this.startActivity(intent);

    }

    public void click2(View view) {

        Intent intent = new Intent(this, SecondActivity.class);

        this.startActivity(intent);

    }

    public void click3(View view) {

        ConnectivityManager manager = (ConnectivityManager) this

                .getSystemService(Context.CONNECTIVITY_SERVICE);

        NetworkInfo info = manager.getActiveNetworkInfo();

        if (info != null && info.isAvailable()) {

            Toast.makeText(this, "网络可用", 0).show();

        } else {

            Toast.makeText(this, "网络不可用", 0).show();

            Intent intent = new Intent();

            intent.setClassName("com.android.phone",

                    "com.android.phone.MiuiSettings");

            this.startActivity(intent);

        }

    }

    public void click4(View view) {

        Intent intent = new Intent();

        intent.setClassName("com.miui.gallery", "com.miui.gallery.app.Gallery");

        this.startActivity(intent);

    }

}

<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

4.隐式意图激活另外一个activity，即打开另外一个app的activity

    public void click(View view) {

        Intent intent = new Intent();

        intent.setAction(Intent.ACTION_VIEW);

        intent.setData(Uri.parse("http://www.baidu.com"));

        this.startActivity(intent);

    }

    public void send(View view) {

        Intent intent = new Intent();

        intent.setAction(Intent.ACTION_SENDTO);

        intent.setData(Uri.parse("sms:10086"));

        intent.addCategory("android.intent.category.DEFAULT");

        this.startActivity(intent);

    }

.隐式意图的配置，自定义隐式意图

第一个activity启动第二个activity

第一个Activity

public class MainActivity extends Activity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

    }

    public void click(View view) {

        Intent intent = new Intent();

        intent.setAction("com.itheima.secondActivity");

        // 额外信息，提供一些执行的环境参数

        intent.addCategory("android.intent.category.DEFAULT");

        intent.setDataAndType(Uri.parse("itheima:jerry"),

                "vnd.android.cursor.item/mp3");

        this.startActivity(intent);

    }

}

第二个Activity

public class SecondActivity extends Activity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_second);

        Intent intent = this.getIntent();

        Uri uri = intent.getData();

        String data = uri.toString();

        String type = intent.getType();

        Toast.makeText(this, "data = " + data + " , type = " + type, 0).show();

    }

}

<activity

    android:name=".SecondActivity"

    android:label="@string/app_name" >

    <intent-filter>

        <action android:name="com.itheima.secondActivity"/>

        <category android:name="android.intent.category.DEFAULT"/>

        <data android:scheme="itheima" android:mimeType="vnd.android.cursor.item/mp3"/>

    </intent-filter>

</activity>

.隐式意图和显示意图的使用场景

同一个应用程序里面，自己激活自己的东西，推荐使用显示意图，效率高

不同的应用程序里面，激活别人的应用，或者是让自己的某一个界面希望被别人激活，推荐使用隐式意图。

7.在不同activity之间数据传递

public void click(View view) {

        String name = this.et_name.getText().toString().trim();

        if (TextUtils.isEmpty(name)) {

            Toast.makeText(this, "姓名不能为空", 0).show();

            return;

        }

        Intent intent = new Intent(this, ResultActivity.class);

        intent.putExtra("name", name);

        this.startActivity(intent);

    }

接收数据

protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_result);

        TextView tv_result = (TextView) this.findViewById(R.id.tv_result);

        Intent intent = this.getIntent();

        String name = intent.getStringExtra("name");

        Random random = new Random();

        int rp = random.nextInt(101);

        tv_result.setText(name + "的人品为：" + rp);

}