Android調用相機並將照片存儲到sd卡上

Android中實現拍照有兩種方法，一種是調用系統自帶的相機，然後使用其返回的照片數據。 還有一種是自己用Camera類和其他相關類實現相機功能，這種方法定制度比較高，洗染也比較復雜，一般平常的應用只需使用第一種即可。

用Intent啟動相機的代碼：

Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(intent, 1);拍完照後就可以在onActivityResult(int requestCode, int resultCode, Intent data)中獲取到Bitmap對象了。 Bitmap bitmap = (Bitmap) data.getExtras().get("data");
要將圖像存儲到sd卡之前最好先檢查一下sd卡是否可用
    String sdStatus = Environment.getExternalStorageState();
            if (!sdStatus.equals(Environment.MEDIA_MOUNTED)) { // 檢測sd是否可用
                Log.v("TestFile",
                        "SD card is not avaiable/writeable right now.");
                return;
            }
以下代碼可以實現將圖像文件存到“sdcard/myImage/”文件夾下，名稱為“111.jpg”

            File file = new File("/sdcard/myImage/");
            file.mkdirs();// 創建文件夾
            String fileName = "/sdcard/myImage/111.jpg";

            try {
                b = new FileOutputStream(fileName);
                bitmap.compress(Bitmap.CompressFormat.JPEG, 100, b);// 把數據寫入文件
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } finally {
                try {
                    b.flush();
                    b.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

另外要注意的是讀寫sd卡文件必須首先要在Mainifest.xml文件中配置權限：
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.MOUNT_UNMOUNT_FILESYSTEMS" />
一個demo，實現調用系統相機拍照，將其顯示在屏幕上，並且存到sd卡。

完整代碼如下：

MyCaremaActivity.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)) { // 檢測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");// 獲取相機返回的數據，並轉換為Bitmap圖片格式
            FileOutputStream b = null;
            File file = new File("/sdcard/myImage/");
            file.mkdirs();// 創建文件夾
            String fileName = "/sdcard/myImage/111.jpg";

            try {
                b = new FileOutputStream(fileName);
                bitmap.compress(Bitmap.CompressFormat.JPEG, 100, b);// 把數據寫入文件
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            } finally {
                try {
                    b.flush();
                    b.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }

            ((ImageView) findViewById(R.id.imageView)).setImageBitmap(bitmap);// 將圖片顯示在ImageView裡
        }
    }
}

main.xml

<?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="點擊啟動相機" />

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

</LinearLayout>

AndroidMainifest.xml

<?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>