0915Android基礎攝像頭

通過Camera進行拍照

調用系統內部camera進行簡單拍照實例

　　權限

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

　　使用Intent隱式啓動相機並告訴相機保存照片位置

  mBtnCamera.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent();
                intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE);//隱式啓動相機
                file=new File(Environment.getExternalStorageDirectory(),System.currentTimeMillis()+".jpg");
                try {
                    file.createNewFile();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(file));//告訴系統相機將照片保存的位置
                startActivityForResult(intent,0x23);
            }
        });

　　將相片壓縮顯示在頁面上

   @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode==0x23){
            if (resultCode==RESULT_OK){
                ZipImage zip=new ZipImage();//得到壓縮類的對象
                zip.zipImage(file.getAbsolutePath());//壓縮圖片，有的手機不顯示特別大的圖片，所以要壓縮，480*960
                mImageView.setImageURI(Uri.fromFile(file));//得到圖片
            }
        }
    }

　　通過按鍵點擊開始按鈕調出系統相機，拍照完成後點擊確定將照片保存在ImageView中。
　　壓縮的類

class ZipImage{
    public void zipImage(String savePath) {
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(savePath, options);
        options.inSampleSize = computeInitialSampleSize(options, 480, 480 * 960);
        options.inJustDecodeBounds = false;
        Bitmap bitmap = BitmapFactory.decodeFile(savePath, options);
        try {
            FileOutputStream fos = new FileOutputStream(savePath);
            bitmap.compress(Bitmap.CompressFormat.JPEG, 90, fos);
            fos.flush();
            fos.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        bitmap.recycle();
        bitmap = null;
        System.gc();
    }
    public int computeSampleSize(BitmapFactory.Options options,
                                 int minSideLength, int maxNumOfPixels) {
        int initialSize = computeInitialSampleSize(options, minSideLength,
                maxNumOfPixels);
        int roundedSize;
        if (initialSize <= 8) {
            roundedSize = 1;
            while (roundedSize < initialSize) {
                roundedSize <<= 1;
            }
        } else {
            roundedSize = (initialSize + 7) / 8 * 8;
        }
        return roundedSize;
    }

    private int computeInitialSampleSize(BitmapFactory.Options options,
                                         int minSideLength, int maxNumOfPixels) {
        double w = options.outWidth;
        double h = options.outHeight;
        int lowerBound = (maxNumOfPixels == -1) ? 1 : (int) Math.ceil(Math
                .sqrt(w * h / maxNumOfPixels));
        int upperBound = (minSideLength == -1) ? 128 : (int) Math.min(
                Math.floor(w / minSideLength), Math.floor(h / minSideLength));
        if (upperBound < lowerBound) {
            // return the larger one when there is no overlapping zone.
            return lowerBound;
        }
        if ((maxNumOfPixels == -1) && (minSideLength == -1)) {
            return 1;
        } else if (minSideLength == -1) {
            return lowerBound;
        } else {
            return upperBound;
        }
    }
}

　　活動代碼

//佈局
<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:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:orientation="vertical"
    android:gravity="center"
    tools:context=".MainActivity">

   <Button
       android:id="@+id/btn_camera"
       android:layout_width="match_parent"
       android:layout_height="wrap_content"
       android:text="打開系統相機"/>
    <ImageView
        android:id="@+id/tv_camera"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />

</LinearLayout>


//活動
package com.example.laowang.mycarema;

import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Environment;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;

import java.io.File;
import java.io.IOException;

public class MainActivity extends Activity {
    private Button mBtnCamera;
    private ImageView mImageView;
    private File file;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mBtnCamera= (Button) findViewById(R.id.btn_camera);
        mImageView= (ImageView) findViewById(R.id.tv_camera);

        mBtnCamera.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent=new Intent();
                intent.setAction(MediaStore.ACTION_IMAGE_CAPTURE);//隱式啓動相機
                file=new File(Environment.getExternalStorageDirectory(),System.currentTimeMillis()+".jpg");
                try {
                    file.createNewFile();
                } catch (IOException e) {
                    e.printStackTrace();
                }
                intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(file));//告訴系統相機將照片保存的位置
                startActivityForResult(intent,0x23);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode==0x23){
            if (resultCode==RESULT_OK){
                mImageView.setImageURI(Uri.fromFile(file));//得到圖片
            }
        }
    }
}

打開相冊並且選取其中的圖片

參考http://blog.csdn.net/to_be_designer/article/details/48500201#t1