Android 保存通过相机拍摄的图像

您好，我制作了一个应用程序，可以打开相机，但位图很小，所以我尝试使用以下代码将其放大：

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (requestCode == REQUEST_TAKE_PHOTO && resultCode == RESULT_OK) {
        Bundle extras = data.getExtras();
        Bitmap imageBitmap = (Bitmap) extras.get("data");
        img.setImageBitmap(imageBitmap);
    }
}
private File createImageFile() throws IOException {
    // Create an image file name
    String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
    String imageFileName = "JPEG_" + timeStamp + "_";
    File storageDir = getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);
    File image = File.createTempFile(
            imageFileName,  /* prefix */
            ".jpg",         /* suffix */
            storageDir      /* directory */
    );

    // Save a file: path for use with ACTION_VIEW intents
    mCurrentPhotoPath = image.getAbsolutePath();
    return image;
}

private void dispatchTakePictureIntent() {
    Intent takePictureIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    // Ensure that there's a camera activity to handle the intent
    if (takePictureIntent.resolveActivity(getPackageManager()) != null) {
        // Create the File where the photo should go
        File photoFile = null;
        try {
            photoFile = createImageFile();
        } catch (IOException ex) {
            // Error occurred while creating the File
        }
        // Continue only if the File was successfully created
        if (photoFile != null) {
            Uri photoURI = FileProvider.getUriForFile(this,
                    "com.example.android.fileprovider",
                    photoFile);
            takePictureIntent.putExtra(MediaStore.EXTRA_OUTPUT, photoURI);
            startActivityForResult(takePictureIntent, REQUEST_TAKE_PHOTO);
        }
    }
}

但在测试之后，我得到了以下错误：

FATAL EXCEPTION: main
              Process: radautiul_civic.e_radauti, PID: 9651
              java.lang.IllegalStateException: Could not execute method for android:onClick
                  at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:293)
                  at android.view.View.performClick(View.java:5716)
                  at android.widget.TextView.performClick(TextView.java:10926)
                  at android.view.View$PerformClick.run(View.java:22596)
                  at android.os.Handler.handleCallback(Handler.java:739)
                  at android.os.Handler.dispatchMessage(Handler.java:95)
                  at android.os.Looper.loop(Looper.java:148)
                  at android.app.ActivityThread.main(ActivityThread.java:7331)
                  at java.lang.reflect.Method.invoke(Native Method)
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)
               Caused by: java.lang.reflect.InvocationTargetException
                  at java.lang.reflect.Method.invoke(Native Method)
                  at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288)
                  at android.view.View.performClick(View.java:5716) 
                  at android.widget.TextView.performClick(TextView.java:10926) 
                  at android.view.View$PerformClick.run(View.java:22596) 
                  at android.os.Handler.handleCallback(Handler.java:739) 
                  at android.os.Handler.dispatchMessage(Handler.java:95) 
                  at android.os.Looper.loop(Looper.java:148) 
                  at android.app.ActivityThread.main(ActivityThread.java:7331) 
                  at java.lang.reflect.Method.invoke(Native Method) 
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230) 
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120) 
               Caused by: java.lang.IllegalArgumentException: Failed to find configured root that contains /storage/emulated/0/Pictures/JPEG_20180119_202116_733528929.jpg
                  at android.support.v4.content.FileProvider$SimplePathStrategy.getUriForFile(FileProvider.java:712)
                  at android.support.v4.content.FileProvider.getUriForFile(FileProvider.java:401)
                  at radautiul_civic.e_radauti.Civic_Alert.dispatchTakePictureIntent(Civic_Alert.java:176)
                  at radautiul_civic.e_radauti.Civic_Alert.runCamera(Civic_Alert.java:313)
                  at radautiul_civic.e_radauti.Civic_Alert.CheckPermissionsCamera(Civic_Alert.java:308)
                  at java.lang.reflect.Method.invoke(Native Method) 
                  at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:288) 
                  at android.view.View.performClick(View.java:5716) 
                  at android.widget.TextView.performClick(TextView.java:10926) 
                  at android.view.View$PerformClick.run(View.java:22596) 
                  at android.os.Handler.handleCallback(Handler.java:739) 
                  at android.os.Handler.dispatchMessage(Handler.java:95) 
                  at android.os.Looper.loop(Looper.java:148) 
                  at android.app.ActivityThread.main(ActivityThread.java:7331) 
                  at java.lang.reflect.Method.invoke(Native Method) 
                  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230) 
                  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120) 

我从以下文档中获取了代码示例：

你们能告诉我我做错了什么吗

我从这个文档中获取了代码示例

不，你改了

文档中的代码示例使用

getExternalFilesDir（）

作为要保存的文件的基本目录。您将其更改为

getExternalStoragePublicDirectory（）

，我假设它是

Environment.getExternalStoragePublicDirectory（）

改变这一点很好。但是，您还需要更改

文件提供程序

元数据以匹配。如果遵循文档中的示例代码，则

FileProvider

元数据如下所示：

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-path name="my_images" path="Android/data/com.example.package.name/files/Pictures" />
</paths>

这是错误的，但是让谷歌修复他们的文档是非常困难的

您需要将其更改为：

<?xml version="1.0" encoding="utf-8"?>
<paths xmlns:android="http://schemas.android.com/apk/res/android">
    <external-path name="my_images" />
</paths>

Ok，所以它现在可以工作了，但在我拍照之后，它在这行给出了错误：Bundle extras=data.getExtras（）；原因：java.lang.NullPointerException:尝试在null对象上调用虚拟方法“android.os.Bundle android.content.Intent.getExtras（）”reference@LuisFernandoScripcaru：在这种情况下，没有返回

Intent

。照片应保存在您要求保存的位置。所以，去那里找吧。