我的Android笔记（五）——调用相机并将照片存储到sd卡上

Android中实现拍照有两种方法，一种是调用系统自带的相机，然后使用其返回的照片数据。 还有一种是自己用Camera类和其他相关类实现相机功能，这种方法定制度比较高，洗染也比较复杂，一般平常的应用只需使用第一种即可。

用Intent启动相机的代码：

[java]
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, 1);
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, 1);
拍完照后就可以在onActivityResult(int requestCode, int resultCode, Intent data)中获取到Bitmap对象了。

[java]
Bitmap bitmap = (Bitmap) data.getExtras().get("data");
Bitmap bitmap = (Bitmap) data.getExtras().get("data");


要将图像存储到sd卡之前最好先检查一下sd卡是否可用


[java]
String sdStatus = Environment.getExternalStorageState();
if (!sdStatus.equals(Environment.MEDIA_MOUNTED)) { // 检测sd是否可用
Log.v("TestFile",
"SD card is not avaiable/writeable right now.");
return;
}
String sdStatus = Environment.getExternalStorageState();
if (!sdStatus.equals(Environment.MEDIA_MOUNTED)) { // 检测sd是否可用
Log.v("TestFile",
"SD card is not avaiable/writeable right now.");
return;
}
以下代码可以实现将图像文件存到“sdcard/myImage/”文件夹下，名称为“111.jpg”


[java]
File file = new File("/sdcard/myImage/");
file.mkdirs();// 创建文件夹
String fileName = "/sdcard/myImage/111.jpg";

try {
b = new FileOutputStream(fileName);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, b);// 把数据写入文件
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally {
try {
b.flush();
b.close();
} catch (IOException e) {
e.printStackTrace();
}
}
File file = new File("/sdcard/myImage/");
file.mkdirs();// 创建文件夹
String fileName = "/sdcard/myImage/111.jpg";

try {
b = new FileOutputStream(fileName);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, b);// 把数据写入文件
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally {
try {
b.flush();
b.close();
} catch (IOException e) {
e.printStackTrace();
}
}另外要注意的是读写sd卡文件必须首先要在Mainifest.xml文件中配置权限：


[html]
<uses-permission Android:name="Android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission Android:name="Android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
<uses-permission Android:name="Android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission Android:name="Android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />

-----------------------------------------------------------------------------------------------------

一个demo，实现调用系统相机拍照，将其显示在屏幕上，并且存到sd卡。

完整代码如下：

MyCaremaActivity.java



[java]
package barry.Android.c;

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

import Android.app.Activity;
import Android.content.Intent;
import Android.graphics.Bitmap;
import Android.os.Bundle;
import Android.os.Environment;
import Android.provider.MediaStore;
import Android.util.Log;
import Android.view.View;
import Android.view.View.OnClickListener;
import Android.widget.Button;
import Android.widget.ImageView;

public class MyCaremaActivity extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

Button button = (Button) findViewById(R.id.button);

button.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, 1);
}
});
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);

if (resultCode == Activity.RESULT_OK) {

String sdStatus = Environment.getExternalStorageState();
if (!sdStatus.equals(Environment.MEDIA_MOUNTED)) { // 检测sd是否可用
Log.v("TestFile",
"SD card is not avaiable/writeable right now.");
return;
}

Bundle bundle = data.getExtras();
Bitmap bitmap = (Bitmap) bundle.get("data");// 获取相机返回的数据，并转换为Bitmap图片格式
FileOutputStream b = null;
File file = new File("/sdcard/myImage/");
file.mkdirs();// 创建文件夹
String fileName = "/sdcard/myImage/111.jpg";

try {
b = new FileOutputStream(fileName);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, b);// 把数据写入文件
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally {
try {
b.flush();
b.close();
} catch (IOException e) {
e.printStackTrace();
}
}

((ImageView) findViewById(R.id.imageView)).setImageBitmap(bitmap);// 将图片显示在ImageView里
}
}
}
package barry.Android.c;

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

import Android.app.Activity;
import Android.content.Intent;
import Android.graphics.Bitmap;
import Android.os.Bundle;
import Android.os.Environment;
import Android.provider.MediaStore;
import Android.util.Log;
import Android.view.View;
import Android.view.View.OnClickListener;
import Android.widget.Button;
import Android.widget.ImageView;

public class MyCaremaActivity extends Activity {

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);

Button button = (Button) findViewById(R.id.button);

button.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View v) {
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, 1);
}
});
}

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);

if (resultCode == Activity.RESULT_OK) {

String sdStatus = Environment.getExternalStorageState();
if (!sdStatus.equals(Environment.MEDIA_MOUNTED)) { // 检测sd是否可用
Log.v("TestFile",
"SD card is not avaiable/writeable right now.");
return;
}

Bundle bundle = data.getExtras();
Bitmap bitmap = (Bitmap) bundle.get("data");// 获取相机返回的数据，并转换为Bitmap图片格式
FileOutputStream b = null;
File file = new File("/sdcard/myImage/");
file.mkdirs();// 创建文件夹
String fileName = "/sdcard/myImage/111.jpg";

try {
b = new FileOutputStream(fileName);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, b);// 把数据写入文件
} catch (FileNotFoundException e) {
e.printStackTrace();
} finally {
try {
b.flush();
b.close();
} catch (IOException e) {
e.printStackTrace();
}
}

((ImageView) findViewById(R.id.imageView)).setImageBitmap(bitmap);// 将图片显示在ImageView里
}
}
}
main.xml[html]
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:Android="http://schemas.Android.com/apk/res/Android"
Android:layout_width="fill_parent"
Android:layout_height="fill_parent"
Android:orientation="vertical" >


<Button
Android:id="@+id/button"
Android:layout_width="fill_parent"
Android:layout_height="wrap_content"
Android:text="点击启动相机" />

<ImageView
Android:id="@+id/imageView"
Android:layout_width="fill_parent"
Android:layout_height="fill_parent"
Android:background="#999999" />

</LinearLayout>
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:Android="http://schemas.Android.com/apk/res/Android"
Android:layout_width="fill_parent"
Android:layout_height="fill_parent"
Android:orientation="vertical" >


<Button
Android:id="@+id/button"
Android:layout_width="fill_parent"
Android:layout_height="wrap_content"
Android:text="点击启动相机" />

<ImageView
Android:id="@+id/imageView"
Android:layout_width="fill_parent"
Android:layout_height="fill_parent"
Android:background="#999999" />

</LinearLayout>

AndroidMainifest.xml


[html]
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:Android="http://schemas.Android.com/apk/res/Android"
package="barry.Android.c"
Android:versionCode="1"
Android:versionName="1.0" >

<uses-sdk Android:minSdkVersion="7" />

<uses-permission Android:name="Android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission Android:name="Android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />

<application
Android:icon="@drawable/ic_launcher"
Android:label="@string/app_name" >
<activity
Android:label="@string/app_name"
Android:name=".MyCaremaActivity" >
<intent-filter >
<action Android:name="Android.intent.action.MAIN" />

<category Android:name="Android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

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

<uses-sdk Android:minSdkVersion="7" />

<uses-permission Android:name="Android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission Android:name="Android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />

<application
Android:icon="@drawable/ic_launcher"
Android:label="@string/app_name" >
<activity
Android:label="@string/app_name"
Android:name=".MyCaremaActivity" >
<intent-filter >
<action Android:name="Android.intent.action.MAIN" />

<category Android:name="Android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
</application>

</manifest>



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代码.zip (110.49KB)