在sdCard存图

1、在AndroidManifest清单文件中添加sdCard权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.MOUNT_FORMAT_FILESYSTEMS"/>

2、存图片的方法

public void savePicture(Bitmap b,String picture){
File file=new File(PATH);
if (!file.exists()) {
//不存在文件就创建文件夹
file.mkdir();
}
//图片路径的file对象
File file1=new File(PATH+picture);
try {
//编写文件流对象
BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream(file1));
//将图片进行压缩
b.compress(CompressFormat.PNG, 80, bos);
bos.flush();
bos.close();
Toast.makeText(MainActivity.this, "保存成功", Toast.LENGTH_SHORT).show();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}

3、读图片的方法

public void getPicture(Bitmap b,ImageView iv){
//图片存储的路径
File file=new File(PATH+picture);
if (file.exists()) {
b=BitmapFactory.decodeFile(PATH+picture);
iv.setImageBitmap(b);
}else {
Toast.makeText(MainActivity.this, "找不到图片", Toast.LENGTH_SHORT).show();
}
}

整体代码

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.sdcard"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.example.sdcard.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />

<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>
<!-- 存储sd卡的权限 -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/> <uses-permission android:name="android.permission.MOUNT_FORMAT_FILESYSTEMS"/>

</manifest>
activity_main.xml

<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:orientation="vertical"
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=".MainActivity" >

<Button
android:id="@+id/get_sd"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="获取sd卡" />
<Button
android:id="@+id/set_sd"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="存入sd卡" />
<ImageView
android:id="@+id/get_picture"
android:layout_width="250dp"
android:layout_height="250dp"
android:layout_gravity="center"/>
</LinearLayout>

package com.example.sdcard;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Bitmap.CompressFormat;
import android.graphics.BitmapFactory;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.Environment;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends Activity implements OnClickListener{
private Button btnSet,btnGet;
private ImageView iv;
//要存入图片在sd卡的路径
private final static String PATH=Environment.getExternalStorageDirectory()+"/savePicture/";
//要存储的图片的名称
private String picture="myicon.png";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btnSet=(Button) findViewById(R.id.set_sd);
btnGet=(Button) findViewById(R.id.get_sd);
btnSet.setOnClickListener(this);
btnGet.setOnClickListener(this);
iv=(ImageView) findViewById(R.id.get_picture);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}

@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.set_sd:
//获取图片对象
Drawable drawable=MainActivity.this.getResources().getDrawable(R.drawable.ic_launcher);
//实现bitmap和drawable直接转换
BitmapDrawable bd=(BitmapDrawable)drawable;
Bitmap b=bd.getBitmap();
//调用自定子存图方法
savePicture(b, picture);
break;
case R.id.get_sd:
//读取图片对象
//
Bitmap b1=null;
getPicture(b1,iv);
break;
default:
break;
}
}
//存图片的方法
public void savePicture(Bitmap b,String picture){
File file=new File(PATH);
if (!file.exists()) {
//不存在文件就创建文件夹
file.mkdir();
}
//图片路径的file对象
File file1=new File(PATH+picture);
try {
//编写文件流对象
BufferedOutputStream bos=new BufferedOutputStream(new FileOutputStream(file1));
//将图片进行压缩
b.compress(CompressFormat.PNG, 80, bos);
bos.flush();
bos.close();
Toast.makeText(MainActivity.this, "保存成功", Toast.LENGTH_SHORT).show();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void getPicture(Bitmap b,ImageView iv){
//图片存储的路径
File file=new File(PATH+picture);
if (file.exists()) {
b=BitmapFactory.decodeFile(PATH+picture);
iv.setImageBitmap(b);
}else {
Toast.makeText(MainActivity.this, "找不到图片", Toast.LENGTH_SHORT).show();
}
}
}