相关疑难解决方法(0)

这两种方法之间的本质区别是什么？当我创建TextView时,我应该使用其中一个来提高性能吗？

编辑:有什么区别

onCreateView() {
  root = some view
  View v = new View(some context);
  root.add(v);
  return root;
}


onViewCreated() {
  View v = new View(some context);
  getView().add(v);
}

我将简单地使用相机生成录像机应用程序。但它崩溃了并给我一个波纹管错误：

尝试在空对象引用上调用虚拟方法 'android.view.SurfaceHolderandroid.view.SurfaceView.getHolder()'

Capture Video Activity.class

import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;

import android.app.Activity;
import android.content.pm.ActivityInfo;
import android.hardware.Camera;
import android.hardware.camera2.CameraCharacteristics;
import android.media.CamcorderProfile;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.util.Log;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.ToggleButton;

import static android.provider.MediaStore.Files.FileColumns.MEDIA_TYPE_IMAGE;
import static android.provider.MediaStore.Files.FileColumns.MEDIA_TYPE_VIDEO;

    public class CaptureVideoActivity extends Activity implements SurfaceHolder.Callback {

        private MediaRecorder mMediaRecorder;
        private Camera mCamera;
        private SurfaceView mSurfaceView;
        private SurfaceHolder mHolder;
        private View mToggleButton;
        private boolean mInitSuccesful;
        CameraCharacteristics characteristics;

        @Override
        public …