android - 在 android 中，相机 "camera.setParameters "失败

Question

 at android.hardware.Camera.native_setParameters(Native Method) at                  
 android.hardware.Camera.setParameters(Camera.java:647) at com.CameraApp.Preview.surfaceChanged(Preview.java:67) at      
 android.view.SurfaceView.updateWindow(SurfaceView.java:538) at 
 android.view.SurfaceView.dispatchDraw(SurfaceView.java:339) at 
 android.view.ViewGroup.drawChild(ViewGroup.java:1638) at 
 android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367) at 
 android.view.ViewGroup.drawChild(ViewGroup.java:1638) at  
 android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367) at 
 android.view.ViewGroup.drawChild(ViewGroup.java:1638) at 
 android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367) at  
 android.view.View.draw(View.java:6743) at 
 android.widget.FrameLayout.draw(FrameLayout.java:352) at 
 android.view.ViewGroup.drawChild(ViewGroup.java:1640) at 
 android.view.ViewGroup.dispatchDraw(ViewGroup.java:1367) at 
 android.view.View.draw(View.java:6743) at 
 android.widget.FrameLayout.draw(FrameLayout.java:352) at 
 com.android.internal.policy.impl.PhoneWindow$DecorView.draw(PhoneWindow.java:1842) at 
 android.view.ViewRoot.draw(ViewRoot.java:1407) at 
 android.view.ViewRoot.performTraversals(ViewRoot.java:1163) at 
 android.view.ViewRoot.handleMessage(ViewRoot.java:1727) at 
 android.os.Handler.dispatchMessage(Handler.java:99) at 
 android.os.Looper.loop(Looper.java:123) at 
 android.app.ActivityThread.main(ActivityThread.java:4627) at 
 java.lang.reflect.Method.invokeNative(Native Method) at 
 java.lang.reflect.Method.invoke(Method.java:521) at 

我也在 2.2 模拟器上运行应用程序来检查它。但它运作良好。谁能告诉我为什么会出现错误？？？

我用的这段代码

    SurfaceHolder mHolder;
    public Camera camera;

    Preview(Context context) {
        super(context);

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



    public void surfaceCreated(SurfaceHolder holder) {
        // The Surface has been created, acquire the camera and tell it where
        // to draw.
         camera = Camera.open();
        try {
            camera.setPreviewDisplay(holder);
        } catch (IOException exception) {
            camera.release();
            camera = null;
            // TODO: add more exception handling logic here
        }
    }

    public void surfaceDestroyed(SurfaceHolder holder) {
        // Surface will be destroyed when we return, so stop the preview.
        // Because the CameraDevice object is not a shared resource, it's very
        // important to release it when the activity is paused.
        camera.stopPreview();
        camera.release();
        camera = null;
    }

    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 = camera.getParameters();
        parameters.setPreviewSize(w, h);
        camera.setParameters(parameters);
        camera.startPreview();
    }

@Override
public void draw(Canvas canvas) {
        super.draw(canvas);
        Paint p= new Paint(Color.RED);
        Log.d(TAG,"draw");
        canvas.drawText("PREVIEW", canvas.getWidth()/2, canvas.getHeight()/2, p );
}

Answer 1

在您的代码中更改它。

public void surfaceChanged(SurfaceHolder holder, int format, int w, int h) {
    Camera.Parameters parameters = camera.getParameters();
    List<Camera.Size> previewSizes = parameters.getSupportedPreviewSizes();

    // You need to choose the most appropriate previewSize for your app
    Camera.Size previewSize = // .... select one of previewSizes here

    parameters.setPreviewSize(previewSize.width, previewSize.height);
    camera.setParameters(parameters);
    camera.startPreview();
}

谢谢..

如果有任何疑问，请告诉我