android - android中的外部存储问题

Question

我正在使用路径"/mnt/sdcard/myfolder/myfile"将我的文件存储在 android 应用程序中。当应用程序在没有任何 sdcard 插槽的手机（像 Nexus S 的手机）上运行时，它会给出任何错误吗？

Answer 1

您必须检查外部存储是否可用

private static boolean isExternalStorageAvailable() {
    String extStorageState = Environment.getExternalStorageState();
    if (Environment.MEDIA_MOUNTED.equals(extStorageState)) {
        return true;
    }
    return false;
}

演示

Answer 2

请检查此链接：

boolean mExternalStorageAvailable = false;
boolean mExternalStorageWriteable = false;
String state = Environment.getExternalStorageState();

if (Environment.MEDIA_MOUNTED.equals(state)) {
    // We can read and write the media
    mExternalStorageAvailable = mExternalStorageWriteable = true;
} else if (Environment.MEDIA_MOUNTED_READ_ONLY.equals(state)) {
    // We can only read the media
    mExternalStorageAvailable = true;
    mExternalStorageWriteable = false;
} else {
    // Something else is wrong. It may be one of many other states, but all we need
    //  to know is we can neither read nor write
    mExternalStorageAvailable = mExternalStorageWriteable = false;
}