安卓 照相機 app 學習筆記

文檔

MainActivity文件

package com.tang.customerCamera;

import java.io.File;
import java.io.FileOutputStream;

import android.app.Activity;
import android.app.ActionBar;
import android.app.Fragment;
import android.content.Context;
import android.content.pm.PackageManager;
import android.hardware.Camera;
import android.hardware.Camera.AutoFocusCallback;
import android.hardware.Camera.PictureCallback;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.Toast;
import android.os.Build;

public class MainActivity extends Activity {
    private Camera mCamera;
    private CameraPreview mPreview;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
        // 建立一個實例
        mCamera = getCameraInstance();
        System.out.println(mCamera);
        //建立一個預覽
        mPreview = new CameraPreview(this, mCamera);
        FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
        preview.addView(mPreview);
        Button captureButton = (Button) findViewById(R.id.button_capture);
        captureButton.setOnClickListener(
            new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                	//讓其自動對焦
                    mCamera.autoFocus(new AutoFocusCallback() {
						public void onAutoFocus(boolean arg0, Camera arg1) {
							 mCamera.takePicture(null, null, mPicture);
						}
					});
                }
            }
        );
	}
	/** 檢查設備是否有照相機*/
	private boolean checkCameraHardware(Context context) {
	    if (context.getPackageManager().hasSystemFeature(PackageManager.FEATURE_CAMERA)){
	        // this device has a camera
	        return true;
	    } else {
	        // no camera on this device
	        return false;
	    }
	}
	
	/** 得到照相機實例. */
	public static Camera getCameraInstance(){
	    Camera c = null;
	    try {
	        c = Camera.open(); // 是前置攝像頭；仍是後置
	    }
	    catch (Exception e){
	        // Camera is not available (in use or does not exist)
	    }
	    return c; // returns null if camera is unavailable
	}
	
	/*拍照回調方法*/
	private PictureCallback mPicture = new PictureCallback() {

	    @Override
	    public void onPictureTaken(byte[] data, Camera camera) {

	        File file = new File("/sdcard/0000"+System.currentTimeMillis()+".jpg");
	        try {
	            FileOutputStream fos = new FileOutputStream(file);
	            fos.write(data);
	            fos.close();
	        } catch (Exception e) {
	        	Toast.makeText(MainActivity.this, "xxa", Toast.LENGTH_SHORT).show();
	        }
	    }
	};
	/*釋放照相機*/ 
	protected void onDestroy() {
		
		if(mCamera != null){
			mCamera.release();
			mCamera = null;
		}
	};
}

預覽類 CameraPreview

package com.tang.customerCamera;

import java.io.IOException;

import android.content.Context;
import android.hardware.Camera;
import android.util.Log;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

/**一個基本的圖片預覽類 */
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
    private static final String TAG = "CameraPreview";
	private SurfaceHolder mHolder;
    private Camera mCamera;

    public CameraPreview(Context context, Camera camera) {
        super(context);
        mCamera = camera;

        // Install a SurfaceHolder.Callback so we get notified when the
        // underlying surface is created and destroyed.
        mHolder = getHolder();
        mHolder.addCallback(this);
        // deprecated setting, but required on Android versions prior to 3.0
        mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
    }

    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, now tell the camera where to draw the preview.
        try {
            mCamera.setPreviewDisplay(holder);
            mCamera.startPreview();
        } catch (IOException e) {
            Log.d(TAG, "Error setting camera preview: " + e.getMessage());
        }
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        // empty. Take care of releasing the Camera preview in your activity.
    }

    public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
        // If your preview can change or rotate, take care of those events here.
        // Make sure to stop the preview before resizing or reformatting it.

        if (mHolder.getSurface() == null){
          // preview surface does not exist
          return;
        }

        // stop preview before making changes
        try {
            mCamera.stopPreview();
        } catch (Exception e){
          // ignore: tried to stop a non-existent preview
        }

        // set preview size and make any resize, rotate or
        // reformatting changes here

        // start preview with new settings
        try {
            mCamera.setPreviewDisplay(mHolder);
            mCamera.startPreview();

        } catch (Exception e){
            Log.d(TAG, "Error starting camera preview: " + e.getMessage());
        }
    }
}

##佈局文件

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="horizontal"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
  <FrameLayout
    android:id="@+id/camera_preview"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:layout_weight="1"
    />

  <Button
    android:id="@+id/button_capture"
    android:text="Capture"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="center"
    />
</LinearLayout>

清單配置

<activity
            android:screenOrientation="landscape"
            android:name="com.tang.customerCamera.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>