Android遊戲開發學習筆記（四）：Camera圖像採集

一、爲相機添加權限。在AndroidManifest.xml文件的</application>之後，添加相機使用的權限：

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

二、編寫佈局文件main.xml，代碼如下：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    >
    <SurfaceView
        android:id="@+id/surfaceView"
        android:layout_width="320px"
        android:layout_height="240px"
        />
    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        >
        <Button
            android:id="@+id/btn1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="打開"
            />
        <Button
            android:id="@+id/btn2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="關閉"
            />
    </LinearLayout>
</LinearLayout>

package game.test;

import android.app.Activity;
import android.hardware.Camera;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity implements SurfaceHolder.Callback {
    Camera myCamera;
    SurfaceView mySurfaceView;
    SurfaceHolder mySurfaceHolder;
    Button btn1, btn2;
    boolean isPreview = false;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mySurfaceView = (SurfaceView) findViewById(R.id.surfaceView);
        btn1 = (Button) findViewById(R.id.btn1);
        btn2 = (Button) findViewById(R.id.btn2);
        mySurfaceHolder = mySurfaceView.getHolder();
        mySurfaceHolder.addCallback(this);
        mySurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
        btn1.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                initCamera();
            }
        });
        btn2.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                if (myCamera != null && isPreview) {
                    myCamera.stopPreview();
                    myCamera.release();
                    myCamera = null;
                    isPreview = false;
                }
            }
        });
    }

    public void initCamera() {
        if (!isPreview) {
            myCamera = Camera.open();
        }
        if (myCamera != null && !isPreview) {
            try {
                myCamera.setPreviewDisplay(mySurfaceHolder);
                myCamera.startPreview();
            } catch (Exception e) {
                e.printStackTrace();
            }
            isPreview = true;
        }
    }

    @Override
    public void surfaceCreated(SurfaceHolder holder) {
        // TODO Auto-generated method stub
    }

    @Override
    public void surfaceChanged(SurfaceHolder holder, int format, int width,
            int height) {
        // TODO Auto-generated method stub
    }

    @Override
    public void surfaceDestroyed(SurfaceHolder holder) {
        // TODO Auto-generated method stub
    }
}