Android 安卓相机预览

我有个问题。 我正在尝试开发一个使用摄像头的程序，所有东西都在我的设备中工作，但正如你们中的许多人所知，

CameraPreview

在所有设备中的工作方式并不相同，因此我尝试将谷歌提供的代码整合到这个地址中：

我面临的问题是，我不知道如何集成到我的项目中，以下是我的代码和我所做的工作，但没有超过：

Preview mPreview;
private Camera mCamera;

    @Override
public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        mPreview = new Preview(this);

        //ContentView----------------------------------------------------------
        setContentView(R.layout.main);

        mSurfaceView = (SurfaceView)findViewById(R.id.camera_surface);

        mPreview.surfacemetod(mSurfaceView);

   @Override
   protected void onResume() {
      // TODO Auto-generated method stub
      super.onResume();    

      mCamera = Camera.open();
      mPreview.setCamera(mCamera);

然后预览类：

class Preview extends ViewGroup implements SurfaceHolder.Callback {
private final String TAG = "Preview";

SurfaceView mSurfaceView;
SurfaceHolder mHolder;
Size mPreviewSize;
List<Size> mSupportedPreviewSizes;
Camera mCamera;

Preview(Context context) {
    super(context);

    mSurfaceView = new SurfaceView(context);
    addView(mSurfaceView);

}

public void surfacemetod(SurfaceView surface){

    //mSurfaceView = new SurfaceView(context);
    //addView(mSurfaceView);

    // Install a SurfaceHolder.Callback so we get notified when the
    // underlying surface is created and destroyed.
    mHolder = mSurfaceView.getHolder();
    mHolder.addCallback(this);
    mHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS);

}

public void setCamera(Camera camera) {
    mCamera = camera;
    if (mCamera != null) {
        mSupportedPreviewSizes = mCamera.getParameters().getSupportedPreviewSizes();
        requestLayout();
    }
}

为空，我得到一个力接近

从本质上看，它并没有进入到解决这些问题的措施中。 有什么想法吗

这是日志：

02-16 13:54:26.068: ERROR/AndroidRuntime(24374): FATAL EXCEPTION: main

02-16 13:54:26.068: ERROR/AndroidRuntime(24374): java.lang.NullPointerException

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at com.dashboard.camera.lite.Preview.surfaceChanged(Preview.java:162)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.SurfaceView.updateWindow(SurfaceView.java:554)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.SurfaceView.dispatchDraw(SurfaceView.java:341)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewGroup.drawChild(ViewGroup.java:1638)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewGroup.drawChild(ViewGroup.java:1638)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.View.draw(View.java:6796)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.widget.FrameLayout.draw(FrameLayout.java:354)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewGroup.drawChild(ViewGroup.java:1640)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.View.draw(View.java:6796)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.widget.FrameLayout.draw(FrameLayout.java:354)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1894)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewRoot.draw(ViewRoot.java:1432)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewRoot.performTraversals(ViewRoot.java:1174)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1752)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.os.Handler.dispatchMessage(Handler.java:99)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.os.Looper.loop(Looper.java:123)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.app.ActivityThread.main(ActivityThread.java:4627)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at java.lang.reflect.Method.invokeNative(Native Method)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at java.lang.reflect.Method.invoke(Method.java:521)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at dalvik.system.NativeStart.main(Native Method)

你能把日志递给我吗？

---

我预测您的mPreview.width/height有问题-很可能是某个不正确的值。

很抱歉，我犯了一个错误，当我在surfacemetod中更改以下行时，我得到了如上所述的力：mHolder=surface.getHolder（）；

02-16 13:54:26.068: ERROR/AndroidRuntime(24374): FATAL EXCEPTION: main

02-16 13:54:26.068: ERROR/AndroidRuntime(24374): java.lang.NullPointerException

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at com.dashboard.camera.lite.Preview.surfaceChanged(Preview.java:162)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.SurfaceView.updateWindow(SurfaceView.java:554)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.SurfaceView.dispatchDraw(SurfaceView.java:341)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewGroup.drawChild(ViewGroup.java:1638)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewGroup.drawChild(ViewGroup.java:1638)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.View.draw(View.java:6796)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.widget.FrameLayout.draw(FrameLayout.java:354)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewGroup.drawChild(ViewGroup.java:1640)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.View.draw(View.java:6796)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.widget.FrameLayout.draw(FrameLayout.java:354)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1894)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewRoot.draw(ViewRoot.java:1432)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewRoot.performTraversals(ViewRoot.java:1174)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1752)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.os.Handler.dispatchMessage(Handler.java:99)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.os.Looper.loop(Looper.java:123)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at android.app.ActivityThread.main(ActivityThread.java:4627)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at java.lang.reflect.Method.invokeNative(Native Method)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at java.lang.reflect.Method.invoke(Method.java:521)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)

02-16 13:54:26.068: ERROR/AndroidRuntime(24374):     at dalvik.system.NativeStart.main(Native Method)