Assets

package com.hanqi.testapp3;

import android.content.SharedPreferences;
import android.content.res.AssetManager;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Environment;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.PrintStream;

public class MainActivity extends AppCompatActivity {

ImageView iv_1;

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);

iv_1 = (ImageView)findViewById(R.id.iv_1);

}

//保存资产文件到内部存储
public void bt4_OnClick(View v)
{
//操作assets目录的文件

//1、得到assetsManager
AssetManager am = getAssets();

try {
//2、操作资产目录，边读边写入
//1）读文件到内存  inputstream
InputStream is = am.open("qiyi.png");

//2)写文件到目录  outputsteam
FileOutputStream fos = openFileOutput("text.png",MODE_PRIVATE);

//先读后写
byte[] b = new byte[1024];
int i = 0;

while ((i=is.read(b)) > 0)
{
fos.write(b,0,i);
}

fos.close();
is.close();

Toast.makeText(MainActivity.this, "保存文件成功", Toast.LENGTH_SHORT).show();

}
catch (Exception ex)
{
Toast.makeText(MainActivity.this, "保存文件出错", Toast.LENGTH_SHORT).show();
}

}

//设置图片指向内部存储
public void bt5_OnClick(View v)
{
//1、得到文件路径
String path = getFilesDir().getAbsolutePath() + "/text.png";

Toast.makeText(MainActivity.this, "path = " + path, Toast.LENGTH_SHORT).show();

//2、从内部存储的图片得到 Bitmap,BitmapFactory.decodeFile("文件路径");
Bitmap bm = BitmapFactory.decodeFile(path);

//3、设置图片视图的图片来源
iv_1.setImageBitmap(bm);
}
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.hanqi.testapp3.MainActivity"
android:orientation="vertical">

<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="保存资产文件到内部存储"
android:onClick="bt4_OnClick"/>

<ImageView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="@+id/iv_1"
android:src="@drawable/apu"/>

<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="设置图片指向内部存储"
android:onClick="bt5_OnClick"/>
</LinearLayout>