使用Android相机拍摄图像后的空指针

在我的应用程序中,我正在使用 Android设备摄像头捕获图像.对于某些设备,它的工作正常,但有些则不行.我刚刚在LG nexus 4 E960上测试过,在我捕获到我的应用程序崩溃的映像后,无法保存结果.
这是我的代码：

//Using intent to open camera
  Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
  startActivityForResult(intent,CAMERA_CAPTURE);

在activityResult中：

protected void onActivityResult(int requestCode,int resultCode,Intent data)
{
    if(resultCode==RESULT_OK)
    {
        if(requestCode==CAMERA_CAPTURE)
        {   
            Bitmap pictTaken = null ;
            Bundle extras = data.getExtras();
            if(extras.keySet().contains("data"))
            {
                pictTaken = (Bitmap) extras.get("data");
                picUri = getIntent().getData();
            }
                    else{
                     picUri = getIntent().getData();
                try {
                    pictTaken = decodeUri(picUri);
                } catch (FileNotFoundException e) {
                    // Todo Auto-generated catch block
                    e.printstacktrace();
                }
                     }
            Intent cropIntent= new Intent (this,Crop.class);
            cropIntent.putExtra("data",picUri.toString());
            cropIntent.putExtra("pict",pictTaken);
            cropIntent.putExtra("code","camera");
            startActivity(cropIntent);
            }
        }

捕获并保存它后,该图像显示在下一个活动中,称为Crop.class
这是我的logcat

12-12 13:26:36.340: E/AndroidRuntime(23575): FATAL EXCEPTION: main
 12-12 13:26:36.340: E/AndroidRuntime(23575): Process: com.example.cobaandroid,PID: 23575
 12-12 13:26:36.340: E/AndroidRuntime(23575): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null,request=1,result=-1,data=Intent { act=inline-data (has extras) }} to activity {com.example.cobaandroid/com.example.cobaandroid.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.toString()' on a null object reference
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.app.ActivityThread.deliverResults(ActivityThread.java:3368)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.app.ActivityThread.handleSendResult(ActivityThread.java:3411)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.app.ActivityThread.access$1300(ActivityThread.java:138)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1247)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.os.Handler.dispatchMessage(Handler.java:102)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.os.Looper.loop(Looper.java:136)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.app.ActivityThread.main(ActivityThread.java:5050)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at java.lang.reflect.Method.invoke(Native Method)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
 12-12 13:26:36.340: E/AndroidRuntime(23575): Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.net.Uri.toString()' on a null object reference
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at com.example.cobaandroid.MainActivity.onActivityResult(MainActivity.java:226)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.app.Activity.dispatchActivityResult(Activity.java:5433)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   at android.app.ActivityThread.deliverResults(ActivityThread.java:3364)
 12-12 13:26:36.340: E/AndroidRuntime(23575):   ... 9 more

我有一个问题要打开/使用在大多数Android设备上工作的相机,这个项目的主要目标在很大程度上取决于使用相机.请给我你的帮助,谢谢..

解决方法

尝试下面的代码,

Intent i = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);

        File file=getoutputMediaFile(1);
        picUri = Uri.fromFile(file); // create
        i.putExtra(MediaStore.EXTRA_OUTPUT,picUri); // set the image file

        startActivityForResult(i,CAPTURE_IMAGE);

其中getoutputMediaFile(int)将是,

/** Create a File for saving an image */
private  File getoutputMediaFile(int type){
    File mediaStorageDir = new File(Environment.getExternalStoragePublicDirectory(
              Environment.DIRECTORY_PICTURES),"MyApplication");

    /**Create the storage directory if it does not exist*/
    if (! mediaStorageDir.exists()){
        if (! mediaStorageDir.mkdirs()){
            return null;
        }
    }

    /**Create a media file name*/
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    File mediaFile;
    if (type == 1){
        mediaFile = new File(mediaStorageDir.getPath() + File.separator +
        "IMG_"+ timeStamp + ".png");
    } else {
        return null;
    }

    return mediaFile;
}

最后,

@Override
public void onActivityResult(int requestCode,Intent data) {
    if (resultCode == Activity.RESULT_OK) {
        Intent i;
        switch (requestCode) {
        case CAPTURE_IMAGE:
            //THIS IS YOUR Uri
            Uri uri=picUri; 
            break;
        }
    }   
}

干杯….：)