我是Android应用程序开发的新手，所以请使用代码示例获得任何答案。
我的问题是，我必须开发一个将mjpeg流式传输到服务器的相机应用程序。
现在我已成功为我的摩托罗拉Atrix创建了应用程序，效果很好。我的问题是在我签署并导出该应用程序并将其安装在HTC Thunderbolt上以进行其他设备测试后，我发现当我尝试呼叫相机并且应用程序崩溃时它会冻结。
从那以后，我尝试了网上和这些论坛中的相机预览的每个示例/示例代码，我不断得到相同的结果。我让它在我的Atrix上工作但不在雷电上工作。
当应用程序在霹雳上运行时，我得到了这个：
07-01 16:11:12.643: D/AndroidRuntime(1140): Shutting down VM
07-01 16:11:12.643: W/dalvikvm(1140): threadid=1: thread exiting with uncaught exception (group=0x40015560)
07-01 16:11:12.653: E/AndroidRuntime(1140): FATAL EXCEPTION: main
07-01 16:11:12.653: E/AndroidRuntime(1140): java.lang.RuntimeException: Fail to connect to camera service
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.hardware.Camera.native_setup(Native Method)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.hardware.Camera.<init>(Camera.java:258)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.hardware.Camera.open(Camera.java:235)
07-01 16:11:12.653: E/AndroidRuntime(1140): at vcore.java.MainActivity.surfaceCreated(MainActivity.java:95)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.view.SurfaceView.updateWindow(SurfaceView.java:543)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.view.SurfaceView.dispatchDraw(SurfaceView.java:348)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.view.ViewGroup.drawChild(ViewGroup.java:1644)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1373)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.view.ViewGroup.drawChild(ViewGroup.java:1644)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1373)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.view.View.draw(View.java:6883)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.widget.FrameLayout.draw(FrameLayout.java:357)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.view.ViewGroup.drawChild(ViewGroup.java:1646)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1373)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.view.View.draw(View.java:6883)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.widget.FrameLayout.draw(FrameLayout.java:357)
07-01 16:11:12.653: E/AndroidRuntime(1140): at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1862)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.view.ViewRoot.draw(ViewRoot.java:1522)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.view.ViewRoot.performTraversals(ViewRoot.java:1258)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.view.ViewRoot.handleMessage(ViewRoot.java:1859)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.os.Handler.dispatchMessage(Handler.java:99)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.os.Looper.loop(Looper.java:123)
07-01 16:11:12.653: E/AndroidRuntime(1140): at android.app.ActivityThread.main(ActivityThread.java:3683)
07-01 16:11:12.653: E/AndroidRuntime(1140): at java.lang.reflect.Method.invokeNative(Native Method)
07-01 16:11:12.653: E/AndroidRuntime(1140): at java.lang.reflect.Method.invoke(Method.java:507)
07-01 16:11:12.653: E/AndroidRuntime(1140): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
07-01 16:11:12.653: E/AndroidRuntime(1140): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
07-01 16:11:12.653: E/AndroidRuntime(1140): at dalvik.system.NativeStart.main(Native Method)
我自己给HTC发了电子邮件，他们说他们根本无法帮助我，所以我想我会在这里试试运气。
有没有人知道如何为HTC Thunderbolt正确调用相机（用于相机预览）？
如果你能提供代码示例，我会永远感激。
我尝试过的一些例子是：
https://stackoverflow.com/a/4798958/1195751
HTC Desire HD not accepts setParameter() with hardware.Camera这也无效
Android: Camera Preview Orientation on HTC EVO (Android 2.1 or 2.2)这不是
我真的已经尝试过一切来解决这个问题，但是没有任何工作可以解决，所以请问这个问题的任何解决方案都会非常有用。
更新我已经在清单中设置了权限
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="vcore.java"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk android:minSdkVersion="8" />
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_MOCK_LOCATION"></uses-permission>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"></uses-permission>
<uses-permission android:name="android.permission.RECORD_AUDIO"></uses-permission>
<uses-permission android:name="android.permission.CAMERA"></uses-permission>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"></uses-permission>
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS"></uses-permission>
<uses-feature android:name="android.hardware.camera" />
<uses-feature android:name="android.hardware.camera.autofocus" />
<uses-permission android:name="android.permission.FLASHLIGHT"
android:permissionGroup="android.permission-group.HARDWARE_CONTROLS"
android:protectionLevel="normal"/>
<uses-feature android:name="android.hardware.camera.flash" />
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE"></uses-permission>
<uses-permission android:name="android.permission.CHANGE_COMPONENT_ENABLED_STATE"></uses-permission>
<uses-permission android:name="android.permission.RECORD_VIDEO"></uses-permission>
<uses-permission android:name="android.permission.WAKE_LOCK" />
<supports-screens
android:largeScreens="true"
android:normalScreens="true"
android:smallScreens="true"
android:anyDensity="true" />
<application
android:icon="@drawable/logo"
android:label="@string/app_name" >
<activity
android:label="@string/app_name"
android:name=".MainActivity"
android:screenOrientation="portrait" >
<intent-filter >
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".PushCamera"
android:label="@string/app_name">
<!-- android:screenOrientation="portrait" -->
</activity>
<activity android:name="ImageDisplayActivity"></activity>
</application>
</manifest>
更新2
public void surfaceCreated(SurfaceHolder holder) {
try {
if (mCamera != null) {
try {
mCamera.stopPreview();
} catch (Exception ignore) {
}
try {
mCamera.release();
} catch (Exception ignore) {
}
mCamera = null;
}
mCamera = Camera.open();
mCamera.setPreviewDisplay(holder);
} catch (Exception ex) {
try {
if (mCamera != null) {
try {
mCamera.stopPreview();
} catch (Exception ignore) {
}
try {
mCamera.release();
} catch (Exception ignore) {
}
mCamera = null;
}
} catch (Exception ignore) {
}
}
}
public void surfaceDestroyed(SurfaceHolder holder) {
try {
if (mCamera != null) {
try {
mCamera.stopPreview();
} catch (Exception ignore) {
}
try {
mCamera.release();
} catch (Exception ignore) {
}
mCamera = null;
}
} catch (Exception ex) {
ex.printStackTrace();
}
}
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
Log.e(TAG, "surfaceChanged");
try {
Camera.Parameters parameters = mCamera.getParameters();
try {
List<Camera.Size> supportedSizes = null;
//On older devices (<1.6) the following will fail
//the camera will work nevertheless
supportedSizes = parameters.getSupportedPreviewSizes();
//preview form factor
float ff = (float)w/h;
Log.d("Mixare", "Screen res: w:"+ w + " h:" + h + " aspect ratio:" + ff);
//holder for the best form factor and size
float bff = 0;
int bestw = 0;
int besth = 0;
Iterator<Camera.Size> itr = supportedSizes.iterator();
//we look for the best preview size, it has to be the closest to the
//screen form factor, and be less wide than the screen itself
//the latter requirement is because the HTC Hero with update 2.1 will
//report camera preview sizes larger than the screen, and it will fail
//to initialize the camera
//other devices could work with previews larger than the screen though
while(itr.hasNext()) {
Camera.Size element = itr.next();
//current form factor
float cff = (float)element.width/element.height;
//check if the current element is a candidate to replace the best match so far
//current form factor should be closer to the bff
//preview width should be less than screen width
//preview width should be more than current bestw
//this combination will ensure that the highest resolution will win
Log.d("Mixare", "Candidate camera element: w:"+ element.width + " h:" + element.height + " aspect ratio:" + cff);
if ((ff-cff <= ff-bff) && (element.width <= w) && (element.width >= bestw)) {
bff=cff;
bestw = element.width;
besth = element.height;
}
}
Log.d("Mixare", "Chosen camera element: w:"+ bestw + " h:" + besth + " aspect ratio:" + bff);
//Some Samsung phones will end up with bestw and besth = 0 because their minimum preview size is bigger then the screen size.
//In this case, we use the default values: 480x320
if ((bestw == 0) || (besth == 0)){
Log.d("Mixare", "Using default camera parameters!");
bestw = 480;
besth = 320;
}
parameters.setPreviewSize(bestw, besth);
} catch (Exception ex) {
parameters.setPreviewSize(480 , 320);
}
mCamera.setParameters(parameters);
mCamera.startPreview();
} catch (Exception ex) {
ex.printStackTrace();
}
}
答案 0 :(得分：0)
您需要在androidmanifest.xml中授予使用相机的权限。
<uses-permission android:name=”android.permission.CAMERA”/>
答案 1 :(得分：0)
public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
if (isPreviewRunning) {
camera.stopPreview();
}
try{
Camera.Parameters p = camera.getParameters();
if(p!=null){
List<Size> sizes = p.getSupportedPreviewSizes();
Size optimalSize = getOptimalPreviewSize(sizes, w, h);
p.setPreviewSize(optimalSize.width, optimalSize.height);
camera.setParameters(p);
camera.setPreviewDisplay(holder);;
camera.startPreview();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
isPreviewRunning = true;
}
private Size getOptimalPreviewSize(List<Size> sizes, int w, int h) {
// TODO Auto-generated method stub
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;
}
将此代码放在surfaceChanged（）中。 getOptimalPreviewSize（）用于根据设备分辨率设置预览参数。 因此，打开相机预览时不会崩溃。 试试这个。 这对我在不同的设备中有用。