使用APi拍照

權限：

<uses-permission android:name="android.permission.CAMERA" />
<uses-feature android:name="android.hardware.camera" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.RECORD_AUDIO" />

預覽界面類：

package com.pas.camera.api;

import java.io.IOException;

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

/** A basic Camera preview class */
public class CameraPreview extends SurfaceView implements SurfaceHolder.Callback {
    private SurfaceHolder mHolder;
    private Camera mCamera;
    
    private static final String TAG="CameraPreview";
    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());
        }
    }
}

MAinAC：

package com.pas.camera.api;

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

import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
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.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.Button;
import android.widget.FrameLayout;
import android.widget.Toast;

public class MainActivity extends Activity {
    protected static final String TAG = "camera";
    private Camera mCamera;
    private CameraPreview mPreview;
    
    
    @Override
    protected void onCreate(Bundle savedInstanceState) {
	super.onCreate(savedInstanceState);
	setContentView(R.layout.activity_main);
	
	if(!checkCameraHardware(this))
	{
	    Toast.makeText(MainActivity.this, "無相機", Toast.LENGTH_SHORT).show();
	    return;
	}
	// 初始化相機
        mCamera = getCameraInstance();

        // 建立預覽界面並設置到activity中.
        FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
        mPreview = new CameraPreview(this, mCamera);
        
        preview.addView(mPreview);
        
        Button captureButton = (Button) findViewById(R.id.button_capture);
        captureButton.setOnClickListener(
            new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    // get an image from the camera
                    //自動對焦
                    mCamera.autoFocus(new AutoFocusCallback() {
		        
		        @Override
		        public void onAutoFocus(boolean success, Camera camera) {
		            
		            //若是要實現無聲拍照 除了主動刪除拍照音頻文件
		            //另外一種方法 就是不使用API快門 而是截圖
		            mCamera.takePicture(null, null, mPicture);
	                    Toast.makeText(MainActivity.this, "已保存", Toast.LENGTH_SHORT).show();
	                    mCamera.startPreview();
		        }
		    });
                   
                }
            }
        );
    }

    /**
     * 釋放相機資源
     */
    @Override
    protected void onDestroy() {
	if(mCamera!=null)
	{
	    mCamera.release();
	    mCamera=null;
	}
        super.onDestroy();
    }
    
    /** 一、檢查是否存在照相機 */
    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;
	}
    }

    /** 二、獲得照相機對象 */
    public static Camera getCameraInstance(){
        Camera c = null;
        try {
            c = Camera.open(); // attempt to get a Camera instance
        }
        catch (Exception e){
            // Camera is not available (in use or does not exist)
        }
        return c; // returns null if camera is unavailable
    }
    
    private PictureCallback mPicture = new PictureCallback() {

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

	        File pictureFile = new File(Environment.getExternalStorageDirectory()+"/"+System.currentTimeMillis()+".jpg");
	        try {
	            FileOutputStream fos = new FileOutputStream(pictureFile);
	            fos.write(data);
	            fos.close();
	        } catch (FileNotFoundException e) {
	            Log.d(TAG, "File not found: " + e.getMessage());
	        } catch (IOException e) {
	            Log.d(TAG, "Error accessing file: " + e.getMessage());
	        }
	    }
	};
}