我正在使用android camera api构建自己的相机应用程序。我有一个工作的应用程序，但预览不如默认的相机应用程序。为什么会这样？以下是我的代码。
public class showCamera extends SurfaceView implements SurfaceHolder.Callback {
private static final int PICTURE_SIZE_MAX_WIDTH =640;
private static final int PREVIEW_SIZE_MAX_WIDTH = 640;
//private Camera theCamera;
private SurfaceHolder holdMe;
private Camera theCamera;
int h;
int w;
public showCamera (Context context,Camera camera,int w,int h)
{
super(context);
theCamera = camera;
holdMe = getHolder();
holdMe.addCallback(this);
this.h=h;
this.w=w;
}
public showCamera(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
// TODO Auto-generated constructor stub
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
// TODO Auto-generated method stub
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
try {
theCamera.setPreviewDisplay(holder);
//setDisplayOrientation(theCamera,90);
if( (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT ))
{ theCamera.setDisplayOrientation(90);
}
Camera.Parameters parameters = theCamera.getParameters();
Log.d(" " , " THIS IS THE FLASH MODE = " + parameters.getFlashMode()) ;
List<String> g= parameters.getSupportedFocusModes();
for(int j=0;j<g.size();j++)
{
Log.d(" " , " THIS IS focus modes =" + g.get(j)) ;
}
Size bestPreviewSize = determineBestPreviewSize(parameters);
Size bestPictureSize = determineBestPictureSize(parameters);
parameters.setPreviewSize(bestPreviewSize.width, bestPreviewSize.height);
parameters.setPictureSize(bestPictureSize.width, bestPictureSize.height);
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
theCamera.setParameters(parameters);
theCamera.startPreview();
} catch (IOException e) {
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
theCamera.stopPreview();
theCamera.release();
// TODO Auto-generated method stub
}
protected void setDisplayOrientation(Camera camera, int angle){
Method downPolymorphic;
try
{
downPolymorphic = camera.getClass().getMethod("setDisplayOrientation", new Class[] { int.class });
if (downPolymorphic != null)
downPolymorphic.invoke(camera, new Object[] { angle });
}
catch (Exception e1)
{
}
}
private Size determineBestPreviewSize(Camera.Parameters parameters) {
List<Size> sizes = parameters.getSupportedPreviewSizes();
return determineBestSize(sizes, PREVIEW_SIZE_MAX_WIDTH);
}
private Size determineBestPictureSize(Camera.Parameters parameters) {
List<Size> sizes = parameters.getSupportedPictureSizes();
return determineBestSize(sizes, PICTURE_SIZE_MAX_WIDTH);
}
protected Size determineBestSize(List<Size> sizes, int widthThreshold) {
Size bestSize = null;
for (Size currentSize : sizes) {
boolean isDesiredRatio = (currentSize.width / 4) == (currentSize.height / 3);
boolean isBetterSize = (bestSize == null || currentSize.width > bestSize.width);
boolean isInBounds = currentSize.width <= PICTURE_SIZE_MAX_WIDTH;
if (isDesiredRatio && isInBounds && isBetterSize) {
bestSize = currentSize;
}
}
if (bestSize == null) {
return sizes.get(0);
}
return bestSize;
}
AutoFocusCallback autoFocusCallback = new AutoFocusCallback() {
@Override
public void onAutoFocus(boolean success, Camera camera) {
Log.i("tag","this ran sdfgfhgjkldxbvnm,jhgfdkmn" );
}
};
}
MainActivity
public class MainActivity extends Activity implements OnClickListener {
private Camera cameraObject;
private showCamera showCamera;
int h;
int w = 1080;
LinearLayout Top, Buttom;
Button b;
public static Camera isCameraAvailiable() {
Camera object = null;
try {
object = Camera.open();
object.getParameters();
} catch (Exception e) {
}
return object;
}
AutoFocusCallback autoFocusCallback = new AutoFocusCallback() {
@Override
public void onAutoFocus(boolean success, Camera camera) {
Log.i("tag", "this ran sdfgfhgjkldxbvnm,jhgfdkmn");
}
};
private PictureCallback capturedIt = new PictureCallback() {
@Override
public void onPictureTaken(byte[] data, Camera camera) {
Bitmap bitmap = BitmapFactory.decodeByteArray(data, 0, data.length);
if (bitmap == null) {
Toast.makeText(getApplicationContext(), "not taken",
Toast.LENGTH_SHORT).show();
} else {
File pictureFile = MediaOutput();
if (pictureFile == null) {
Log.d("",
"Error creating media file, check storage permissions: ");
return;
}
try {
FileOutputStream fos = new FileOutputStream(pictureFile);
fos.write(data);
MediaStore.Images.Media.insertImage(getContentResolver(),
bitmap, "testing ", "");
Toast.makeText(getApplicationContext(), "taken",
Toast.LENGTH_SHORT).show();
fos.close();
} catch (FileNotFoundException e) {
Log.d("", "File not found: " + e.getMessage());
} catch (IOException e) {
Log.d("", "Error accessing file: " + e.getMessage());
}
}
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.camlay);
Top = (LinearLayout) findViewById(R.id.top_bar);
Buttom = (LinearLayout) findViewById(R.id.but_bar);
b = (Button) findViewById(R.id.but_pic);
b.setOnClickListener(this);
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
int height = size.y;
h = (int) Math.round(0.8 * height);
Log.d(" ", " height " + h);
Log.d(" ", " width " + width);
Top.setLayoutParams(new LinearLayout.LayoutParams(width, (int) Math
.round(0.10 * height)));
Buttom.setLayoutParams(new LinearLayout.LayoutParams(width, (int) Math
.round(0.10 * height)));
cameraObject = isCameraAvailiable();
showCamera = new showCamera(this, cameraObject, width, h);
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(showCamera, new FrameLayout.LayoutParams(width, h));
// preview.addView(showCamera);
}
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
switch (v.getId()) {
case R.id.but_pic:
// cameraObject.takePicture(null, null,capturedIt);
// parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
Camera.Parameters parameters = cameraObject.getParameters();
parameters.setFocusMode(Camera.Parameters.FOCUS_MODE_AUTO);
cameraObject.setParameters(parameters);
cameraObject.autoFocus(autoFocusCallback);
// cameraObject.stopPreview();
break;
}
}
private static File MediaOutput() {
File mediaStorageDir = new File(
Environment
.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
"MyCameraApp");
if (!mediaStorageDir.exists()) {
if (!mediaStorageDir.mkdirs()) {
Log.d("MyCameraApp", "failed to create directory");
return null;
}
}
String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss")
.format(new Date());
File mediaFile;
mediaFile = new File(mediaStorageDir.getPath() + File.separator
+ "IMG_" + timeStamp + ".jpg");
return mediaFile;
}
}
如果你可以指出我的方向很好。
答案 0 :(得分：0)
您是否曾尝试在showCamera类中增加这些值：
private static final int PICTURE_SIZE_MAX_WIDTH = 640;
private static final int PREVIEW_SIZE_MAX_WIDTH = 640;