android-data storage of the internal phone file storage

I. Basic outline

1. Description:

1> application operation requires some large data or images can be stored inside the phone

2> file Type: arbitrary

3> Path:/data/data/packagename/files/

4> Delete this data file when uninstalling an app

5> can also set permissions for manipulating data files (same as sharedpreferences)

Second, practice

1>fileinputstream fis=openfileinput ("logo.png"); Read file

2>fileoutputstream fos=openfileoutput ("Logo.png", mode_private); Save File

3>file Filesdir=getfilesdir (); Get Files Folder object

4> the file under Operation asserts:

. Context.getassets () gets Assetmanager

.  InputStream open (filename); Read file

5> Loading picture files:

Bitmap bitmap=bitmapfactory.decodefile (String pathName); (drawable: Indicates that a picture object can be drawn)

　　

Save diagram File:

1> get InputStream: Read assets under Logo.png

Assetmanager manager=getassets ();

2> reading files

InputStream Is=manager.open ("logo.png");

3> Get OutputStream:/data/data/packagename/files/logo.png

FileOutputStream fos=openfileoutput ("Logo.png", context.mode_private);

4> Read Side write:

Byte[] Buffer=new byte[1024];

int len=-1;

while ((Len=is.read (buffer))!=-1) {

Fos.write (Buffer,0,len);

}

Fos.close ();

Is.close ();

To read a picture:

1> Get picture path:/data/data/packagename/files

String Filespath=getfiledir (). GetAbsolutePath ();

String imgpath=filespath+ "/logo.png";

2> loading picture file to get Bitmap object:

Bitmap Bitmap=bitmapfactory.decodefile (Imgpath);

3> set it to ImageView display:

Iv_if.setimagebitmap (bitmap);

Third, the source code

Save Picture:

Assetmanager manager=getassets ();
InputStream Is=manager.open ("logo.png");
FileOutputStream fos= openfileoutput ("Logo.png", context.mode_private);
Byte[] Buffer=new byte[1024];
int len=-1;
while ((Len=is.read (buffer))!=-1) {
Fos.write (buffer, 0, Len);
}
Fos.close ();
Is.close ();
Toast.maketext (Mainactivity.this, "saved successfully", Toast.length_short). Show ();

To read a picture:

android-data storage of the internal phone file storage