2

我正在开发自己的自定义相机应用程序,在运行应用程序时,如果我单击捕获按钮,我的相机将捕获当前位置。我真正需要的是在需要时重新拍摄照片。但是如果我单击重新拍摄(拍照)按钮该应用程序将崩溃。我在下面附上了我的代码。所以请任何人帮助我解决错误。

MainActivity.java

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.view.View.OnClickListener;
import android.widget.Button;
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;
       private Button takePhotoButton;
       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);    
          takePhotoButton = (Button)findViewById(R.id.button_takephoto);
          cameraObject = isCameraAvailiable();
          showCamera = new ShowCamera(this, cameraObject);
          FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
          preview.addView(showCamera);



          takePhotoButton.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                  cameraObject = isCameraAvailiable();

                  cameraObject.stopPreview();
                    showCamera = new ShowCamera(getApplicationContext(), cameraObject);
                      FrameLayout preview = (FrameLayout) findViewById(R.id.camera_preview);
                      preview.addView(showCamera);
            }
        });

       }
       public void snapIt(View view){
          cameraObject.takePicture(null, null, capturedIt);
       }

       @Override
       public void onPause(){
           super.onPause();
       }

       @Override
       public boolean onCreateOptionsMenu(Menu menu) {
          getMenuInflater().inflate(R.menu.activity_main, menu);
          return true;
       }
    }

ShowCamera.java

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.setDisplayOrientation(90);
             theCamera.setPreviewDisplay(holder);
             theCamera.startPreview(); 
          } catch (IOException e) {
          }
       }

       @Override
       public void surfaceDestroyed(SurfaceHolder arg0) {

           theCamera.stopPreview(); 
       }

    }

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
   android:layout_width="fill_parent"
   android:layout_height="fill_parent"
   android:orientation="horizontal" >

   <LinearLayout
      android:layout_width="match_parent"
      android:layout_height="match_parent"
      android:layout_weight="0.30"
      android:orientation="vertical" >

         <FrameLayout
            android:id="@+id/camera_preview"
            android:layout_width="fill_parent"
            android:layout_height="350dp" />

         <RelativeLayout
             android:layout_width="match_parent"
             android:layout_height="wrap_content" >

             <Button
                 android:id="@+id/button_capture"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:onClick="snapIt"
                 android:text="@string/Capture" />

             <Button
                 android:id="@+id/button_takephoto"
                 android:layout_width="match_parent"
                 android:layout_height="wrap_content"
                 android:layout_below="@+id/button_capture"
                 android:text="Take Photo" />
         </RelativeLayout>

   </LinearLayout>

</LinearLayout>
4

2 回答 2

3

我想原因是你打电话cameraObject.release();来的onPictureTaken。你可以删除它。而且,别忘了再打电话startPreview()

因为:

此方法仅在预览处于活动状态时有效(在 startPreview() 之后)。拍照后预览将停止;如果要重新开始预览或拍摄更多照片,调用者必须再次调用 startPreview()。这不应该在 start() 和 stop() 之间调用。

调用此方法后,在 JPEG 回调返回之前,您不得调用 startPreview() 或拍摄另一张照片。

于 2014-05-28T05:44:33.640 回答
0
cameraObject.release();

从 tour 中删除这条线PictureCallback。现在您知道为什么您的应用程序崩溃对我来说很直接,您还没有开始camera并且preview 在您捕获图像之后也是如此。Preview是在你打电话后停止的事情PictureCallback,你已经手动恢复了。

如果您不想管理这件事,那么我可以建议您使用非常棒的 cwac-camera库。您需要做的就是扩展您的 Fragment ,CameraFragment然后您将负责管理这些东西。

享受 !

于 2014-05-28T05:57:36.303 回答