Android的 - 无法找到文件，虽然它在数据文件夹中存在？

问题描述

我想SQLite数据库从数据文件夹复制使用模拟器到SD卡，我用下面code，我发现here.

I am trying to copy the SQLite database from the data folder to SDCard using Emulator, i am using below code, which i found here.

try {
    File sd = Environment.getExternalStorageDirectory();
    File data = Environment.getDataDirectory();

    if (sd.canWrite()) {
        String currentDBPath = "\\data\\PackageName\\databases\\myDB.db";
        String backupDBPath = "myDB.db";
        File currentDB = new File(data, currentDBPath);
        File backupDB = new File(sd, backupDBPath);

        if (currentDB.exists())
        {
           // code to copy from currentDB  to backupDB
        }
    }
} catch (Exception e) {
}

有关写权限下面也被添加到清单文件：

For write permission below is also added to manifest file:

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

问题

的问题是，currentDB.exists（）返回FALSE 。

在currentDB.getAbsolutePath（）返回，这是数据\\数据\\ PACKAGENAME \\ \\数据库myDB.db

The "currentDB.getAbsolutePath()" returns the path which is "data\data\PackageName\databases\myDB.db"

这是数据库的正确位置，因为我可以找到使用它的Eclipse >> DDMS透视图>>文件浏览器

This is the correct location of the database, because i can find it using Eclipse >> DDMS perspective >> File Explorer

有人可以帮我找到问题为什么currentDB.exists（）返回FALSE？

Can somebody help me find the issue why the "currentDB.exists()" returns FALSE?

感谢您的宝贵时间和放大器;帮助。

Thanks for your valuable time & help.

推荐答案

好，大家好我只是删除了 .db的扩展名和放大器;它的工作原理吧！
请参阅更新的code以下：

Well guys i just removed the ".db" extension & it works now!See the updated code below:

try
 {
    File sd = Environment.getExternalStorageDirectory();
    File data = Environment.getDataDirectory();

    if (sd.canWrite()) {
        String currentDBPath = "\\data\\PackageName\\databases\\myDB";
        String backupDBPath = "myDB";
        File currentDB = new File(data, currentDBPath);
        File backupDB = new File(sd, backupDBPath);

        if (currentDB.exists())
        {
           // code to copy from currentDB  to backupDB
        }
    }
} catch (Exception e) {
}

myDB.db替换为 MYDB

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