一：Notification的使用

使用步驟：

流程模組：

第一步：
建立一個通知欄的Builder構造類 （Create a Notification Builder）
第二步：
定義通知欄的Action （Define the Notification’s Action）
第三步：
設定通知欄點選事件 （Set the Notification’s Click Behavior）
第四步：
通知 （Issue the Notification）

notification案例：

                   //1，獲取notificationManager
                    myManager = (NotificationManager) context.getSystemService
 
(NOTIFICATION_SERVICE);
                    //3.定義一個PendingIntent，點選Notification後啟動一個Broadcast
//                    PendingIntent intent = PendingIntent.getBroadcast(
//                            context,
//                            100,
//                            new Intent(context, NotificationClickReceiver.class
 
),
//                            PendingIntent.FLAG_CANCEL_CURRENT
//                    );
                    //3.定義一個PendingIntent，點選Notification後啟動一個Activity

                    PendingIntent intent = PendingIntent.getActivity(context, 100,
                            new Intent(context, NotificationActivity.class
 
),
                            PendingIntent.FLAG_UPDATE_CURRENT);

                    //2.通過Notification.Builder來建立通知
                    Notification.Builder myBuilder = new Notification.Builder(context);
                    myBuilder.setContentTitle("檔案下載")
                            .setContentText("下載的檔案是：" + keyName + sky)
                            .setTicker("您收到新的訊息")
                            //設定狀態列中的小圖片，尺寸一般建議在24×24，這個圖片同樣也是在下拉狀態列中所顯示
                            .setSmallIcon(R.drawable.ic_launcher)
                            //設定預設聲音和震動
                            .setDefaults(Notification.DEFAULT_SOUND | Notification.DEFAULT_VIBRATE)
                            .setAutoCancel(true)//點選後取消
                            .setWhen(System.currentTimeMillis())//設定通知時間
                            //android5.0加入了一種新的模式Notification的顯示等級，共有三種：
                            //VISIBILITY_PUBLIC  只有在沒有鎖屏時會顯示通知
                            //VISIBILITY_PRIVATE 任何情況都會顯示通知
                            //VISIBILITY_SECRET  在安全鎖和沒有鎖屏的情況下顯示通知
                            .setContentIntent(intent);  //3.關聯PendingIntent
                    myNotification = myBuilder.build();
                    //4.通過通知管理器來發起通知，ID區分通知
                    myManager.notify(0, myNotification);

接受到通知，響應點選事件

二：Intent開啟各種檔案：

直接看程式碼：

package com.zte.meeting.ui.notification;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.FragmentActivity;
import android.view.View;
import android.widget.ImageButton;
import android.widget.TextView;

import com.zte.meeting.R;
import com.zte.meeting.util.SharePreferenceUtil;

import java.io.File;

/**
 * Created by lovelin on 2017/4/17.
 */

public class NotificationActivity extends FragmentActivity {
    private final String[][] MIME_MapTable = {     //{字尾名，MIME型別}
            {".3gp", "video/3gpp"},
            {".apk", "application/vnd.android.package-archive"},
            {".asf", "video/x-ms-asf"},
            {".avi", "video/x-msvideo"},
            {".bin", "application/octet-stream"},
            {".bmp", "image/bmp"},
            {".c", "text/plain"},
            {".class", "application/octet-stream"},
            {".conf", "text/plain"},
            {".cpp", "text/plain"},
            {".doc", "application/msword"},
            {".docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document"},
            {".xls", "application/vnd.ms-excel"},
            {".xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"},
            {".exe", "application/octet-stream"},
            {".gif", "image/gif"},
            {".gtar", "application/x-gtar"},
            {".gz", "application/x-gzip"},
            {".h", "text/plain"},
            {".htm", "text/html"},
            {".html", "text/html"},
            {".jar", "application/java-archive"},
            {".java", "text/plain"},
            {".jpeg", "image/jpeg"},
            {".jpg", "image/jpeg"},
            {".js", "application/x-JavaScript"},
            {".log", "text/plain"},
            {".m3u", "audio/x-mpegurl"},
            {".m4a", "audio/mp4a-latm"},
            {".m4b", "audio/mp4a-latm"},
            {".m4p", "audio/mp4a-latm"},
            {".m4u", "video/vnd.mpegurl"},
            {".m4v", "video/x-m4v"},
            {".mov", "video/quicktime"},
            {".mp2", "audio/x-mpeg"},
            {".mp3", "audio/x-mpeg"},
            {".mp4", "video/mp4"},
            {".mpc", "application/vnd.mpohun.certificate"},
            {".mpe", "video/mpeg"},
            {".mpeg", "video/mpeg"},
            {".mpg", "video/mpeg"},
            {".mpg4", "video/mp4"},
            {".mpga", "audio/mpeg"},
            {".msg", "application/vnd.ms-outlook"},
            {".ogg", "audio/ogg"},
            {".pdf", "application/pdf"},
            {".png", "image/png"},
            {".pps", "application/vnd.ms-powerpoint"},
            {".ppt", "application/vnd.ms-powerpoint"},
            {".pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation"},
            {".prop", "text/plain"},
            {".rc", "text/plain"},
            {".rmvb", "audio/x-pn-realaudio"},
            {".rtf", "application/rtf"},
            {".sh", "text/plain"},
            {".tar", "application/x-tar"},
            {".tgz", "application/x-compressed"},
            {".txt", "text/plain"},
            {".wav", "audio/x-wav"},
            {".wma", "audio/x-ms-wma"},
            {".wmv", "audio/x-ms-wmv"},
            {".wps", "application/vnd.ms-works"},
            {".xml", "text/plain"},
            {".z", "application/x-compress"},
            {".zip", "application/x-zip-compressed"},
            {"", "*/*"}
    };
    private String path;
    private TextView tv_notii_file;
    private ImageButton break_;
    private TextView tvTitle;
    private String type;
    private String currentType;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_notification);
        path = (String) SharePreferenceUtil.get(this, SharePreferenceUtil.NOTIFICATION_PATCH, SharePreferenceUtil.NOTIFICATION_DEFFOUR);
        initView();
        responseListener();
    }

    private void initView() {
        tv_notii_file = (TextView) findViewById(R.id.tv_notii_file);
        break_ = (ImageButton) findViewById(R.id.break_);
        tvTitle = (TextView) findViewById(R.id.tvTitle);
        initDate();
    }

    private void initDate() {
        setDownFileName();
        break_.setVisibility(View.VISIBLE);
        tvTitle.setText("當前下載檔案");
    }

    private void responseListener() {
        tv_notii_file.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                openFile(new File(path).getAbsoluteFile());
            }
        });

        break_.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                finish();
            }
        });
    }


    /**
     * 設定大部分檔案的通俗名
     */
    private void setDownFileName() {
        int i = path.lastIndexOf("/");
        String substring = path.substring(i, path.length());
        int i1 = substring.lastIndexOf(".");
        currentType = substring.substring(i1, substring.length());
        switch (currentType) {
            case ".doc":   //文件
                tv_notii_file.setText("當前下載是:" + "(" + "World文件" + ")" + "檔案");
                break;
            case ".docx":
                tv_notii_file.setText("當前下載是:" + " (" + "World文件" + ")" + " 檔案");
                break;
            case ".xls":   //表格
                tv_notii_file.setText("當前下載是:" + " (" + "Excel表格" + ")" + " 檔案");

                break;
            case ".xlsx":
                tv_notii_file.setText("當前下載是:" + " (" + "Excel表格" + ")" + " 檔案");
                break;
            case ".ppt":   //文件
                tv_notii_file.setText("當前下載是:" + "(" + "PPT" + ")" + "檔案");
                break;
            case ".pptx":   //文件
                tv_notii_file.setText("當前下載是:" + "(" + "PPT" + ")" + "檔案");
                break;
            case ".png":  //圖片
                tv_notii_file.setText("當前下載是:" + " (" + ".png圖片" + ")" + " 檔案");

                break;
            case ".jpg":
                tv_notii_file.setText("當前下載是:" + " (" + ".jpg圖片" + ")" + " 檔案");

                break;
            case ".mp3":  //音樂
                tv_notii_file.setText("當前下載是:" + " (" + ".mp3音樂" + ")" + " 檔案");

                break;
            case ".mp4":
                tv_notii_file.setText("當前下載是:" + " (" + ".mp4音樂" + ")" + " 檔案");

                break;
            case ".avi":  //視訊
                tv_notii_file.setText("當前下載是:" + " (" + ".avi視訊" + ")" + " 檔案");

                break;
            default:
                tv_notii_file.setText("當前下載是:" + " (" + currentType + ")" + " 檔案");
                break;
        }
    }

    /**
     * 開啟檔案
     *
     * @param file
     */
    private void openFile(File file) {

        Intent intent = new Intent();
        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
        //設定intent的Action屬性
        intent.setAction(Intent.ACTION_VIEW);
        //獲取檔案file的MIME型別
        type = getMIMEType(file);
        //設定intent的data和Type屬性。
        intent.setDataAndType(/*uri*/Uri.fromFile(file), type);
        //跳轉
        startActivity(intent); //這裡最好try一下，有可能會報錯。 //比如說你的MIME型別是開啟郵箱，但是你手機裡面沒裝郵箱客戶端，就會報錯。

    }

    /**
     * 根據檔案字尾名獲得對應的MIME型別。
     *
     * @param file
     */
    private String getMIMEType(File file) {

        String type = "*/*";
        String fName = file.getName();
        //獲取字尾名前的分隔符"."在fName中的位置。
        int dotIndex = fName.lastIndexOf(".");
        if (dotIndex < 0) {
            return type;
        }
        /* 獲取檔案的字尾名*/
        String end = fName.substring(dotIndex, fName.length()).toLowerCase();
        if (end == "") return type;
        //在MIME和檔案型別的匹配表中找到對應的MIME型別。
        for (int i = 0; i < MIME_MapTable.length; i++) { //MIME_MapTable??在這裡你一定有疑問，這個MIME_MapTable是什麼？
            if (end.equals(MIME_MapTable[i][0]))
                type = MIME_MapTable[i][1];
        }
        return type;
    }

}

最後：註釋程式碼都有自己看