我是一名学生,我正在Android 2.2上开发一个项目。对于我的测试和应用程序执行,我使用的是HTC Desire HD(使用Android 2.2)。
我只是想创建一个合成器(类)来用移动设备拍照。我有一个Android类,我用于getOptimalPreviewSize()方法(此方法在ApiDemos 2.2中)。此方法用于修复此类错误:
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): java.lang.RuntimeException: Fail to connect to camera service
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.hardware.Camera.native_setup(Native Method)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.hardware.Camera.<init>(Camera.java:118)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.hardware.Camera.open(Camera.java:91)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at com.example.android.apis.graphics.Preview.surfaceCreated(CameraPreview.java:69)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.view.SurfaceView.updateWindow(SurfaceView.java:540)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.view.SurfaceView.dispatchDraw(SurfaceView.java:339)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.view.ViewGroup.drawChild(ViewGroup.java:1660)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1389)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.view.View.draw(View.java:6764)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.widget.FrameLayout.draw(FrameLayout.java:352)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.view.ViewGroup.drawChild(ViewGroup.java:1662)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1389)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.view.View.draw(View.java:6764)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.widget.FrameLayout.draw(FrameLayout.java:352)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1887)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.view.ViewRoot.draw(ViewRoot.java:1422)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.view.ViewRoot.performTraversals(ViewRoot.java:1167)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.view.ViewRoot.handleMessage(ViewRoot.java:1744)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.os.Handler.dispatchMessage(Handler.java:99)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.os.Looper.loop(Looper.java:143)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at android.app.ActivityThread.main(ActivityThread.java:5068)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at java.lang.reflect.Method.invokeNative(Native Method)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at java.lang.reflect.Method.invoke(Method.java:521)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
02-14 21:38:05.818: ERROR/AndroidRuntime(2884): at dalvik.system.NativeStart.main(Native Method)
所以,我用这段代码解决了这个问题:
public class CameraView extends Activity implements SurfaceHolder.Callback {
private SurfaceView mSurfaceView = null;
private SurfaceHolder mSurfaceHolder = null;
private Camera mCamera = null;
private boolean mPreviewRunning = false;
public void onCreate(Bundle icicle) {
super.onCreate(icicle);
getWindow().setFormat(PixelFormat.TRANSLUCENT);
//requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.camera_surface);
mSurfaceView = (SurfaceView) findViewById(R.id.surface_camera);
mSurfaceHolder = mSurfaceView.getHolder();
mSurfaceHolder.addCallback(this);
mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
if (!(android.os.Environment.getExternalStorageState().equals(
android.os.Environment.MEDIA_MOUNTED)))
{
Toast
.makeText(CameraView.this, R.string.msgNoSdCard, Toast.LENGTH_LONG)
.show();
}
else
{
Toast
.makeText(CameraView.this, R.string.msgPressBackBt, Toast.LENGTH_LONG)
.show();
}
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
// TODO Auto-generated method stub
mCamera = Camera.open();
try {
mCamera.setPreviewDisplay(holder);
} catch (IOException exception) {
mCamera.release();
mCamera = null;
// TODO: add more exception handling logic here
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
mCamera.stopPreview();
mPreviewRunning = false;
mCamera.release();
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
//Handle the back button
if ((keyCode == KeyEvent.KEYCODE_DPAD_CENTER) || (keyCode == KeyEvent.KEYCODE_CAMERA)){
mCamera.takePicture(shutterCallback, rawCallback, jpegCallback);
return true;
}
else {
return super.onKeyDown(keyCode, event);
}
}
ShutterCallback shutterCallback = new ShutterCallback() {
public void onShutter() {
}
};
/** Handles data for raw picture */
PictureCallback rawCallback = new PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera) {
}
};
/** Handles data for jpeg picture */
PictureCallback jpegCallback = new PictureCallback() {
public void onPictureTaken(byte[] data, Camera camera) {
FileOutputStream outStream = null;
try {
// write to local sandbox file system
//outStream =
//CameraView.this.openFileOutput(String.format("%d.jpg",
//System.currentTimeMillis()), 0);
// Or write to sdcard
long fileName = System.currentTimeMillis();
outStream = new FileOutputStream(String.format(
"/sdcard/%d.jpg", fileName));
outStream.write(data);
outStream.close();
Intent resultIntent = new Intent();
String imageFileName = String.format("/sdcard/%d.jpg", fileName);
resultIntent.putExtra("MyAvatar", imageFileName);
setResult(Activity.RESULT_OK, resultIntent);
} catch (FileNotFoundException e) {
e.printStackTrace();
}
catch (IOException e) {
e.printStackTrace();
}
finally {
}
}
};
private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
final double ASPECT_TOLERANCE = 0.05;
double targetRatio = (double) w / h;
if (sizes == null) return null;
Size optimalSize = null;
double minDiff = Double.MAX_VALUE;
int targetHeight = h;
// Try to find an size match aspect ratio and size
for (Size size : sizes) {
double ratio = (double) size.width / size.height;
if (Math.abs(ratio - targetRatio) > ASPECT_TOLERANCE) continue;
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
// Cannot find the one match the aspect ratio, ignore the requirement
if (optimalSize == null) {
minDiff = Double.MAX_VALUE;
for (Size size : sizes) {
if (Math.abs(size.height - targetHeight) < minDiff) {
optimalSize = size;
minDiff = Math.abs(size.height - targetHeight);
}
}
}
return optimalSize;
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// Now that the size is known, set up the camera parameters and begin
// the preview.
Camera.Parameters parameters = mCamera.getParameters();
List<Size> sizes = parameters.getSupportedPreviewSizes();
Size optimalSize = getOptimalPreviewSize(sizes, w, h);
parameters.setPreviewSize(optimalSize.width, optimalSize.height);
mCamera.setParameters(parameters);
mCamera.startPreview();
}
}
最后一个问题是:如果设备显示摄像机视图,设备完全迷失方向。如果我将相机指向房间的顶部(拍摄的场景),屏幕会向左移动,如果我将相机放到地面,屏幕就会向右移动。横向屏幕的高度和宽度错误以及摄像机方向也存在同样的问题。
是否有解决方案来解决使用HTC Desire HD的Camera API问题?
谢谢,
相关链接:
Android 2.2 SDK - setParameters failed for Camera API on Nexus One
答案 0 :(得分:3)
问题与手机无关,而是您为相机分辨率设置的参数。在学习在Nexus One上使用相机时,我遇到了类似的问题。您需要获取已知解决方案的列表,这些解决方案适用于代码正在处理的电话,并将其设置为其中之一。
你确定参数不起作用吗?你能发布不起作用的代码吗?也许你做错了。
答案 1 :(得分:0)
Ok, problem resolved with this code :
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
// Now that the size is known, set up the camera parameters and begin
// the preview.
Camera.Parameters parameters = mCamera.getParameters();
List<Size> sizes = parameters.getSupportedPreviewSizes();
Size optimalSize = getOptimalPreviewSize(sizes, w, h);
parameters.setPreviewSize(optimalSize.width, optimalSize.height);
mCamera.setDisplayOrientation(90);
parameters.setRotation(90);
mCamera.setParameters(parameters);
mCamera.startPreview();
}
答案 2 :(得分:0)
好的,我发现了另一个简单的解决方案:
在Android Manifest中,添加相机活动此属性:
android:screenOrientation="landscape"
并且,在Camera App for surfaceChanged:
就是这样:
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
Camera.Parameters parameters = mCamera.getParameters();
mCamera.setParameters(parameters);
mCamera.startPreview();
}
问候。