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);
}