您好我正在编写一个直接与机器人相机API交互的简单应用，我正在使用本教程http://www.tutorialspoint.com/android/android_camera.htm
有谁能告诉我哪里出错了？
日志输出：
01-09 23:42:56.901: D/ATRecorder(886): com.htc.autotest.dlib.RecordEngine in loader dalvik.system.DexClassLoader@40528bb8
01-09 23:42:57.161: D/AndroidRuntime(886): Shutting down VM
01-09 23:42:57.161: W/dalvikvm(886): threadid=1: thread exiting with uncaught exception (group=0x400205a0)
01-09 23:42:57.171: E/AndroidRuntime(886): FATAL EXCEPTION: main
01-09 23:42:57.171: E/AndroidRuntime(886): java.lang.RuntimeException: startPreview failed
01-09 23:42:57.171: E/AndroidRuntime(886): at android.hardware.Camera.startPreview(Native Method)
01-09 23:42:57.171: E/AndroidRuntime(886): at com.example.camera1.ShowCamera.surfaceCreated(ShowCamera.java:30)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.SurfaceView.updateWindow(SurfaceView.java:551)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.SurfaceView.dispatchDraw(SurfaceView.java:348)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.ViewGroup.drawChild(ViewGroup.java:1730)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1459)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.ViewGroup.drawChild(ViewGroup.java:1730)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1459)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.ViewGroup.drawChild(ViewGroup.java:1730)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1459)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.ViewGroup.drawChild(ViewGroup.java:1730)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1459)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.View.draw(View.java:6973)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.widget.FrameLayout.draw(FrameLayout.java:357)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.ViewGroup.drawChild(ViewGroup.java:1732)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1459)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.ViewGroup.drawChild(ViewGroup.java:1730)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1459)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.View.draw(View.java:6973)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.widget.FrameLayout.draw(FrameLayout.java:357)
01-09 23:42:57.171: E/AndroidRuntime(886): at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1997)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.ViewRoot.draw(ViewRoot.java:1600)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.ViewRoot.performTraversals(ViewRoot.java:1321)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.view.ViewRoot.handleMessage(ViewRoot.java:1957)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.os.Handler.dispatchMessage(Handler.java:99)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.os.Looper.loop(Looper.java:150)
01-09 23:42:57.171: E/AndroidRuntime(886): at android.app.ActivityThread.main(ActivityThread.java:4277)
01-09 23:42:57.171: E/AndroidRuntime(886): at java.lang.reflect.Method.invokeNative(Native Method)
01-09 23:42:57.171: E/AndroidRuntime(886): at java.lang.reflect.Method.invoke(Method.java:507)
01-09 23:42:57.171: E/AndroidRuntime(886): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
01-09 23:42:57.171: E/AndroidRuntime(886): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
01-09 23:42:57.171: E/AndroidRuntime(886): at dalvik.system.NativeStart.main(Native Method)
我完全遵循了它，但是当我尝试运行它时，我仍然在log-cat中获得并且未捕获异常，这是MainActivity中的代码：
package com.example.camera1;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.hardware.Camera;
import android.hardware.Camera.PictureCallback;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends Activity {
private Camera cameraObject;
private ShowCamera showCamera;
private ImageView pic;
public static Camera isCameraAvailiable(){
Camera object = null;
try {
object = Camera.open();
}
catch (Exception e){
}
return object;
}
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
{
Toast.makeText(getApplicationContext(), "taken", Toast.LENGTH_SHORT).show();
}
cameraObject.release();
}
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
pic = (ImageView)findViewById(R.id.imageView1);
cameraObject = isCameraAvailiable();
showCamera = new ShowCamera(this, cameraObject);
FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
preview.addView(showCamera);
}
public void snapIt(View view){
cameraObject.takePicture(null, null, capturedIt);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
这是ShowCamera类：
package com.example.camera1;
import java.io.IOException;
import android.content.Context;
import android.hardware.Camera;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
public class ShowCamera extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder holdMe;
private Camera theCamera;
public ShowCamera(Context context,Camera camera) {
super(context);
theCamera = camera;
holdMe = getHolder();
holdMe.addCallback(this);
}
@Override
public void surfaceChanged(SurfaceHolder arg0, int arg1, int arg2, int arg3) {
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
try {
theCamera.setPreviewDisplay(holder);
theCamera.startPreview();
} catch (IOException e) {
}
}
@Override
public void surfaceDestroyed(SurfaceHolder arg0) {
}
}
答案 0 :(得分：0)
尝试在surfaceCreated方法中捕获顶级异常（而不是IOException），并在异常块中调用e.getMessage（）以获取有关错误类型的更多信息。
答案 1 :(得分：0)
Camera.startPreview()投掷RuntimeException可能有不同的原因。对于example，可以通过设置预览尺寸而不是支持的预览尺寸之一。