我正在开发一个应用程序，它可以在服务器调用时获取图像并将该图像发送到服务器。下面是我在CameraSurfaceView类中定义的一些代码。
private SurfaceHolder holder;
private Camera camera;
private Bitmap osb;
public void takeImage(){
Camera camera = this.getCamera();
CameraSurfaceView.HandlePictureStorage c = this.new HandlePictureStorage();
camera.takePicture(null, null, c);
}
public byte[] getImage(String type) {
if (osb==null) {
System.err.println("Camera.getImage: osb NULL");
return null;
}
CompressFormat format = CompressFormat.JPEG;
if (type.equals("PNG")) {
format = CompressFormat.PNG;
}
ByteArrayOutputStream out = new ByteArrayOutputStream();
try {
System.err.println("Camera.getImage: decoded");
osb.compress(format, 100, out);
System.err.println("Camera.getImage: compressed");
try {
out.close();
} catch (IOException e) {
e.printStackTrace();
}
} finally {
//lock.unlock();
}
byte[] bytes = out.toByteArray();
return bytes;
}
public void saveImage(byte[] picture) {
System.err.println("saveImage");
osb = BitmapFactory.decodeByteArray(picture, 0, picture.length);
}
内部类实现
@Override
public void onPictureTaken(byte[] picture, Camera camera)
{
CameraSurfaceView.this.saveImage(picture);
}
当我从外部调用
HandlePictureStorage函数，然后从外部调用PictureCallBack函数时，我希望takeImage()类的getImage()上的代码将在onPictureTaken(byte[] picture, Camera camera)之后执行以保存图像，在HandlePictureStorage之前执行，因此takeImage()有数据可供检索。不幸的是，当我在logcat上看到时，
getImage()函数在getImage()之后和getImage()之前运行。因此，很明显takeImage()只能获得空数据，因为之前没有保存图片。如果再次运行
onPictureTaken()和takeImage，函数takeImage()将返回上一个快照的图片。 最佳答案
CameraProjectActivity.java ----> main activity
public class CameraProjectActivity extends Activity
{
public static ImageView image;
private Button btn_camera;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
image = (ImageView) findViewById(R.id.image);
btn_camera = (Button) findViewById(R.id.btn_camera);
btn_camera.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View v)
{
Intent i = new Intent(CameraProjectActivity.this,CameraView.class);
startActivityForResult(i, 999);
}
});
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent intent)
{
if(requestCode==999)
{
if(resultCode==585)
{
//Intent Works
}
else
{
alert("Picture not Captured!");
}
}
}
private void alert(String string)
{
AlertDialog.Builder alert=new AlertDialog.Builder(CameraProjectActivity.this);
alert.setMessage(string);
alert.setTitle("Alert");
alert.setNeutralButton("Ok",null);
alert.show();
}
}
CameraView.java
public class CameraView extends Activity implements SurfaceHolder.Callback, OnClickListener
{
private static final String TAG = "CameraTest";
Camera mCamera;
boolean mPreviewRunning = false;
public void onCreate(Bundle icicle)
{
super.onCreate(icicle);
Log.e(TAG, "onCreate");
getWindow().setFormat(PixelFormat.TRANSLUCENT);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.cameraview);
mSurfaceView = (SurfaceView) findViewById(R.id.surface_camera);
mSurfaceView.setOnClickListener(this);
mSurfaceHolder = mSurfaceView.getHolder();
mSurfaceHolder.addCallback(this);
mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
@Override
protected void onRestoreInstanceState(Bundle savedInstanceState)
{
super.onRestoreInstanceState(savedInstanceState);
}
Camera.PictureCallback mPictureCallback = new Camera.PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
// TODO Auto-generated method stub
if (data != null)
{
//Intent mIntent = new Intent();
//mIntent.putExtra("image",imageData);
mCamera.stopPreview();
mPreviewRunning = false;
mCamera.release();
try
{
BitmapFactory.Options opts = new BitmapFactory.Options();
Bitmap bitmap= BitmapFactory.decodeByteArray(data, 0, data.length,opts);
bitmap = Bitmap.createScaledBitmap(bitmap, 480, 480, false);
CameraProjectActivity.image.setImageBitmap(bitmap);
}
catch(Exception e)
{
e.printStackTrace();
}
//StoreByteImage(mContext, imageData, 50,"ImageName");
//setResult(FOTO_MODE, mIntent);
setResult(585);
finish();
}
}
};
protected void onResume()
{
Log.e(TAG, "onResume");
super.onResume();
}
protected void onSaveInstanceState(Bundle outState)
{
super.onSaveInstanceState(outState);
}
protected void onStop()
{
Log.e(TAG, "onStop");
super.onStop();
}
public void surfaceCreated(SurfaceHolder holder)
{
Log.e(TAG, "surfaceCreated");
mCamera = Camera.open();
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
Log.e(TAG, "surfaceChanged");
// XXX stopPreview() will crash if preview is not running
if (mPreviewRunning)
{
mCamera.stopPreview();
}
Camera.Parameters p = mCamera.getParameters();
p.setPreviewSize(w, h);
mCamera.setParameters(p);
try
{
mCamera.setPreviewDisplay(holder);
}
catch (Exception e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
mCamera.startPreview();
mPreviewRunning = true;
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
Log.e(TAG, "surfaceDestroyed");
//mCamera.stopPreview();
//mPreviewRunning = false;
//mCamera.release();
}
private SurfaceView mSurfaceView;
private SurfaceHolder mSurfaceHolder;
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
mCamera.takePicture(null, mPictureCallback, mPictureCallback);
}
}
cameraview.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">
<SurfaceView android:id="@+id/surface_camera"
android:layout_width="fill_parent" android:layout_height="10dip"
android:layout_weight="1">
</SurfaceView>
</LinearLayout>
main.xml
<?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">
<Button android:id="@+id/btn_camera"
android:text="Take a Picture from Camera"
android:layout_height="wrap_content"
android:layout_width="wrap_content"
android:gravity="center"
>
</Button>
<ImageView
android:layout_height="480px"
android:layout_width="480px"
android:scaleType="fitXY"
android:id="@+id/image"
android:src="@drawable/android"
/>
</LinearLayout>
// Dont forgot to add the below code in AndroidManifest.xml
// <uses-permission android:name="android.permission.CAMERA"></uses-permission>
// <uses-feature android:name="android.hardware.camera" />
// <uses-feature android:name="android.hardware.camera.autofocus" />