Assets

 1 package com.hanqi.testapp3;
 2
 3 import android.content.SharedPreferences;
 4 import android.content.res.AssetManager;
 5 import android.graphics.Bitmap;
 6 import android.graphics.BitmapFactory;
 7 import android.os.Bundle;
 8 import android.os.Environment;
 9 import android.support.v7.app.AppCompatActivity;
10 import android.view.View;
11 import android.widget.EditText;
12 import android.widget.ImageView;
13 import android.widget.TextView;
14 import android.widget.Toast;
15
16 import java.io.File;
17 import java.io.FileInputStream;
18 import java.io.FileOutputStream;
19 import java.io.InputStream;
20 import java.io.PrintStream;
21
22 public class MainActivity extends AppCompatActivity {
23
24     ImageView iv_1;
25
26     @Override
27     protected void onCreate(Bundle savedInstanceState) {
28         super.onCreate(savedInstanceState);
29         setContentView(R.layout.activity_main);
30
31         iv_1 = (ImageView)findViewById(R.id.iv_1);
32
33     }
34
35 //保存资产文件到内部存储
36     public void bt4_OnClick(View v)
37     {
38         //操作assets目录的文件
39
40         //1、得到assetsManager
41         AssetManager am = getAssets();
42
43         try {
44             //2、操作资产目录，边读边写入
45             //1）读文件到内存  inputstream
46             InputStream is = am.open("qiyi.png");
47
48             //2)写文件到目录  outputsteam
49             FileOutputStream fos = openFileOutput("text.png",MODE_PRIVATE);
50
51             //先读后写
52             byte[] b = new byte[1024];
53             int i = 0;
54
55             while ((i=is.read(b)) > 0)
56             {
57                 fos.write(b,0,i);
58             }
59
60             fos.close();
61             is.close();
62
63             Toast.makeText(MainActivity.this, "保存文件成功", Toast.LENGTH_SHORT).show();
64
65         }
66         catch (Exception ex)
67         {
68             Toast.makeText(MainActivity.this, "保存文件出错", Toast.LENGTH_SHORT).show();
69         }
70
71     }
72
73
74
75     //设置图片指向内部存储
76     public void bt5_OnClick(View v)
77     {
78         //1、得到文件路径
79         String path = getFilesDir().getAbsolutePath() + "/text.png";
80
81         Toast.makeText(MainActivity.this, "path = " + path, Toast.LENGTH_SHORT).show();
82
83         //2、从内部存储的图片得到 Bitmap,BitmapFactory.decodeFile("文件路径");
84         Bitmap bm = BitmapFactory.decodeFile(path);
85
86         //3、设置图片视图的图片来源
87         iv_1.setImageBitmap(bm);
88     }
89 }

 1 <?xml version="1.0" encoding="utf-8"?>
 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
 3     xmlns:tools="http://schemas.android.com/tools"
 4     android:layout_width="match_parent"
 5     android:layout_height="match_parent"
 6     android:paddingBottom="@dimen/activity_vertical_margin"
 7     android:paddingLeft="@dimen/activity_horizontal_margin"
 8     android:paddingRight="@dimen/activity_horizontal_margin"
 9     android:paddingTop="@dimen/activity_vertical_margin"
10     tools:context="com.hanqi.testapp3.MainActivity"
11     android:orientation="vertical">
12
13     <Button
14         android:layout_width="match_parent"
15         android:layout_height="wrap_content"
16         android:text="保存资产文件到内部存储"
17         android:onClick="bt4_OnClick"/>
18
19     <ImageView
20         android:layout_width="wrap_content"
21         android:layout_height="wrap_content"
22         android:id="@+id/iv_1"
23         android:src="@drawable/apu"/>
24
25     <Button
26         android:layout_width="match_parent"
27         android:layout_height="wrap_content"
28         android:text="设置图片指向内部存储"
29         android:onClick="bt5_OnClick"/>
30 </LinearLayout>