Java NullPointerException当我尝试捕获图像（内置照相机）并将其保存到文件时

以下是应用程序的功能-用户单击按钮在活动a上拍照，捕获的图像在活动a的ImageView上设置为，然后用户单击保存按钮，将其带到活动B，在活动B的ImageView上显示他们拍摄的图像

为了做到这一点，我试图找到一种方法来保存图像。我尝试了很多不同的方法，但是我总是得到一个NullPointerException。这是我的密码：

我强调了我认为错误所在的区域：

 public void onClick(View view) {
    switch (view.getId()) {
        case R.id.take_picture_button:
            takePic = new Intent(android.provider.MediaStore.ACTION_IMAGE_CAPTURE);
            if (takePic.resolveActivity(getPackageManager()) != null) {
                File photoFile = null;
                try {
                    photoFile = createImageFile(); //so photoFile = the file we created up top
                } catch (IOException ex) {
                    // Error occurred while creating the File
                    ex.printStackTrace();

                }
                // Continue only if the File was successfully created
                if (photoFile != null) {

                    **takePic.putExtra(MediaStore.EXTRA_OUTPUT**, //extra_output is just the name of the Intent-extra used to indicate a content resolver Uri to be used to store the requested image or video.
                            **Uri.fromFile(photoFile));**
                    startActivityForResult(takePic, cameraData);
                }

这是onActivityResult的代码

 @Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    if (requestCode == cameraData && resultCode == RESULT_OK) {
        mReturningWithResult = true;
        extras = data.getExtras();

在这里，我将图像视图设置为活动A上捕获的图像

@Override
protected void onPostResume() {
    super.onPostResume();
    if (mReturningWithResult) {
        foodImage = (Bitmap) extras.get("data");
        foodImageView.setImageBitmap(foodImage);
    }
    mReturningWithResult = false;//resetting it for next time

}

这是日志抱歉我是新手

    10-15 20:58:59.612  32005-32005/com.example.nikhil.foodshark D/OpenGLRenderer﹕ Enabling debug mode    0
10-15 20:59:21.545  32005-32005/com.example.nikhil.foodshark I/PersonaManager﹕ getPersonaService() name persona_policy
10-15 20:59:23.127  32005-32005/com.example.nikhil.foodshark W/IInputConnectionWrapper﹕ showStatusIcon on inactive InputConnection
10-15 20:59:33.678  32005-32005/com.example.nikhil.foodshark D/AndroidRuntime﹕ Shutting down VM
10-15 20:59:33.678  32005-32005/com.example.nikhil.foodshark W/dalvikvm﹕ threadid=1: thread exiting with uncaught exception (group=0x41a39da0)
10-15 20:59:33.678  32005-32005/com.example.nikhil.foodshark E/AndroidRuntime﹕ FATAL EXCEPTION: main
    Process: com.example.nikhil.foodshark, PID: 32005
    java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=1, result=-1, data=null} to activity {com.example.nikhil.foodshark/com.example.nikhil.foodshark.NewDish}: java.lang.NullPointerException
            at android.app.ActivityThread.deliverResults(ActivityThread.java:3680)
            at android.app.ActivityThread.handleSendResult(ActivityThread.java:3723)
            at android.app.ActivityThread.access$1400(ActivityThread.java:174)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1355)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:146)
            at android.app.ActivityThread.main(ActivityThread.java:5593)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
            at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.NullPointerException
            at com.example.nikhil.foodshark.NewDish.onActivityResult(NewDish.java:144)
            at android.app.Activity.dispatchActivityResult(Activity.java:5650)
            at android.app.ActivityThread.deliverResults(ActivityThread.java:3676)
            at android.app.ActivityThread.handleSendResult(ActivityThread.java:3723)
            at android.app.ActivityThread.access$1400(ActivityThread.java:174)
            at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1355)
            at android.os.Handler.dispatchMessage(Handler.java:102)
            at android.os.Looper.loop(Looper.java:146)
            at android.app.ActivityThread.main(ActivityThread.java:5593)
            at java.lang.reflect.Method.invokeNative(Native Method)
            at java.lang.reflect.Method.invoke(Method.java:515)
            at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283)
            at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099)
            at dalvik.system.NativeStart.main(Native Method)
10-15 20:59:56.353  32005-32005/com.example.nikhil.foodshark I/Process﹕ Sending signal. PID: 32005 SIG: 9
10-15 20:59:56.613      378-378/com.example.nikhil.foodshark I/PersonaManager﹕ getPersonaService() name persona_policy
10-15 20:59:56.723      378-378/com.example.nikhil.foodshark I/Adreno-EGL﹕ <qeglDrvAPI_eglInitialize:381>: EGL 1.4 QUALCOMM build: AU_LINUX_ANDROID_KK_2.7_RB1.04.04.02.007.050_msm8960_refs/tags/AU_LINUX_ANDROID_KK_2.7_RB1.04.04.02.007.050__release_AU ()
    OpenGL ES Shader Compiler Version: 17.01.12.SPL
    Build Date: 03/28/14 Fri
    Local Branch:
    Remote Branch: refs/tags/AU_LINUX_ANDROID_KK_2.7_RB1.04.04.02.007.050
    Local Patches: NONE
    Reconstruct Branch: NOTHING
10-15 20:59:56.763      378-378/com.example.nikhil.foodshark D/OpenGLRenderer﹕ Enabling debug mode 0

你们知道我怎么解决这个问题吗？谢谢大家!

您正在传递MediaStore.EXTRA_输出，在这种情况下，onActivityResult中的intent字段可以为null

解决方案是只使用您创建的照片文件，并在putExtra中作为uri传递

因此，不要试图从意图中获取照片文件位置，只需使用Uri.fromFilephotoFile

替换

    extras = data.getExtras();
    ...

与

---

或者，如果你想要的话，就直接使用photoFile…不要依赖意图数据

什么是空指针异常？请张贴stacktrace。不要说..我认为错误在哪里。堆栈跟踪准确地告诉错误在哪里。在这里发布我没有看到任何突出显示的区域我只看到评论也发布你的stacktrace以便我们可以帮助嘿伙计们对不起我是新来的-我发布了日志什么是新菜144行？谢谢你ashoke以及所有其他帮助过我的人-我想我现在明白了！

   `Uri.fromFile(photoFile)`