accessing file from sdcard???

Development Platform & Builds Mobile
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1

whole day i was trying to get access of a file “t.txt” that i had put in my sdcard:


FString InPath="/mnt/sdcard/t.txt";
FString InPath="/sdcard/t.txt";
FString InPath="./t.txt";

FPaths::FileExists(InPath)

then i tried to check its existence with FPaths::FileExists(InPath).
but it always was returning false.

what InPath value I should have use to get proper address?

note:
i also have added read permission under:
project settings->android->extra permissions:
android.permission.WRITE_EXTERNAL_STORAGE
android.permission.READ_EXTERNAL_STORAGE

3

i figured out that i have to use something like this:

FString myfile= GFilePathBase + FString(TEXT("/t.txt") ;

GFilePathBase defination can be found in “Runtime\Launch\Private\Android\AndroidJNI.cpp”

// Cache path to external storage
jclass EnvClass = Env->FindClass("android/os/Environment");
jmethodID getExternalStorageDir = Env->GetStaticMethodID(EnvClass, "getExternalStorageDirectory", "()Ljava/io/File;");
jobject externalStoragePath = Env->CallStaticObjectMethod(EnvClass, getExternalStorageDir, nullptr);
jmethodID getFilePath = Env->GetMethodID(Env->FindClass("java/io/File"), "getPath", "()Ljava/lang/String;");
jstring pathString = (jstring)Env->CallObjectMethod(externalStoragePath, getFilePath, nullptr);
const char *nativePathString = Env->GetStringUTFChars(pathString, 0);
// Copy that somewhere safe 
GFilePathBase = FString(nativePathString);

but problem is how to access "GFilePathBase ";?

4

can somebody from epic’s android department answer how to get the correct path for c++ as string?
there should be simple a simple answer of this.
the whole process is now pending because of this silly issue.

5

You can access GFilePathBase by adding an extern FString GFilePathBase; if you know you are on Android (use #if PLATFORM_ANDROID / #endif around the code that uses it).