在阅读本教程后,我写了一个小相机应用程序:
http://www.brighthub.com/mobile/google-android/articles/43414.aspx
在模拟器中一切正常(好吧,没有摄像头,但至少没有错误;))
然后我尝试让它在我的 HTC Wildfire S 上运行。但应用程序在启动后立即崩溃。
这是我的 Activity 代码,也许有人有想法,如何解决问题:
public class CameraView extends Activity implements SurfaceHolder.Callback {
android.hardware.Camera mCamera;
boolean mPreviewRunning = false;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
getWindow().setFormat(PixelFormat.TRANSLUCENT);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.camera_surface);
SurfaceView mSurfaceView = (SurfaceView)findViewById(R.id.surface_camera);
SurfaceHolder mSurfaceHolder = mSurfaceView.getHolder();
mSurfaceHolder.addCallback(this);
mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
mCamera = android.hardware.Camera.open();
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width,
int height) {
if(mPreviewRunning) {
mCamera.stopPreview();
}
android.hardware.Camera.Parameters params = mCamera.getParameters();
params.setPreviewSize(width, height);
mCamera.setParameters(params);
try {
mCamera.setPreviewDisplay(holder);
} catch (IOException ex) {
ex.printStackTrace();
}
mCamera.startPreview();
mPreviewRunning = true;
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
mCamera.stopPreview();
mPreviewRunning = false;
mCamera.release();
}
android.hardware.Camera.PictureCallback mPictureCallback = new android.hardware.Camera.PictureCallback() {
@Override
public void onPictureTaken(byte[] data, android.hardware.Camera camera) {
}
};
}
最佳答案
您遇到异常是因为您试图让相机使用它不支持的宽度和高度。您要求它使用 SurfaceView 的宽度和高度,这很少与受支持的预览尺寸之一匹配。相反,请尝试使用以下内容:
public class CameraView extends Activity implements SurfaceHolder.Callback {
android.hardware.Camera mCamera;
boolean mPreviewRunning = false;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
getWindow().setFormat(PixelFormat.TRANSLUCENT);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN, WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.camera_surface);
SurfaceView mSurfaceView = (SurfaceView)findViewById(R.id.surface_camera);
SurfaceHolder mSurfaceHolder = mSurfaceView.getHolder();
mSurfaceHolder.addCallback(this);
mSurfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
try {
mCamera.setPreviewDisplay(previewHolder);
}
catch (Throwable t) {
Log.e(TAG, "Exception in setPreviewDisplay()", t);
}
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
Camera.Parameters parameters=camera.getParameters();
Camera.Size size=getBestPreviewSize(width, height, parameters);
if (size!=null) {
parameters.setPreviewSize(size.width, size.height);
camera.setParameters(parameters);
camera.startPreview();
inPreview=true;
}
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
mCamera.stopPreview();
mPreviewRunning = false;
mCamera.release();
}
android.hardware.Camera.PictureCallback mPictureCallback = new android.hardware.Camera.PictureCallback() {
@Override
public void onPictureTaken(byte[] data, android.hardware.Camera camera) {
}
};
private Camera.Size getBestPreviewSize(int width, int height, Camera.Parameters parameters) {
Camera.Size result=null;
for (Camera.Size size : parameters.getSupportedPreviewSizes()) {
if (size.width<=width && size.height<=height) {
if (result==null) {
result=size;
}
else {
int resultArea=result.width*result.height;
int newArea=size.width*size.height;
if (newArea>resultArea) {
result=size;
}
}
}
}
return(result);
}
}
这段代码全部改编 self 为我的书写的代码。我更改了您的一些代码,因此可能需要修复一些变量名称和导入,但它应该可以正常工作。
getBestPreviewSize() 是这里的神奇方法,它计算要使用的最佳和最佳相机预览尺寸。
关于java - CameraView 仅适用于模拟器,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/12087854/