我正在开发相机应用程序，我必须单击该图像 并将其保存在新创建的SD卡中的图像文件夹中
这是我的MainActivity.java文件。
public class MainActivity extends Activity {
Button cambutton;
ImageView photoImage=null;
private static final String TAG = "CallCamera";
private static final int CAPTURE_IMAGE_ACTIVITY_REQ = 0;
Uri fileUri=null;
//ImageView photoImage1 = null;
private File getOutputPhotoFile() {
File directory = new File(Environment.getExternalStoragePublicDirectory(
Environment.DIRECTORY_PICTURES), getPackageName());
if (!directory.exists()) {
if (!directory.mkdirs()) {
Log.e(TAG, "Failed to create storage directory.");
return null;
}
}
String timeStamp = new SimpleDateFormat("yyyMMdd_HHmmss", Locale.US).format(new Date());
return new File(directory.getPath() + File.separator + "IMG_"
+ timeStamp + ".jpg");
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button camButton = (Button)findViewById(R.id.btncam);
ImageView photoImage = (ImageView)findViewById(R.id.iv);
camButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent i = new Intent (MediaStore.ACTION_IMAGE_CAPTURE);
fileUri = Uri.fromFile(getOutputPhotoFile());
i.putExtra(MediaStore.EXTRA_OUTPUT,fileUri);
startActivityForResult(i, CAPTURE_IMAGE_ACTIVITY_REQ);
}
});
}
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if (requestCode == CAPTURE_IMAGE_ACTIVITY_REQ) {
if (resultCode == RESULT_OK) {
Uri photoUri = null;
if (data == null) {
// A known bug here! The image should have saved in fileUri
Toast.makeText(this, "Image saved successfully",
Toast.LENGTH_LONG).show();
photoUri = fileUri;
} else {
photoUri = data.getData();
Toast.makeText(this, "Image saved successfully in: " + data.getData(),
Toast.LENGTH_LONG).show();
}
showPhoto(photoUri.getPath());
} else if (resultCode == RESULT_CANCELED) {
Toast.makeText(this, "Cancelled", Toast.LENGTH_SHORT).show();
} else {
Toast.makeText(this, "Callout for image capture failed!",
Toast.LENGTH_LONG).show();
}
}
}
private void showPhoto(String photoUri) {
File imageFile = new File (photoUri);
if (imageFile.exists()){
Bitmap bitmap = BitmapFactory.decodeFile(imageFile.getAbsolutePath());
BitmapDrawable drawable = new BitmapDrawable(this.getResources(), bitmap);
photoImage.setScaleType(ImageView.ScaleType.FIT_CENTER);
photoImage.setImageDrawable(drawable);
}
}
}
当我运行它时，它运行得很好但是当我尝试保存图像时，应用程序崩溃了。
我的logcat如下所示。
07-08 03:51:02.976: W/dalvikvm(2104): threadid=1: thread exiting with uncaught exception (group=0xb1d4bb20)
07-08 03:51:02.986: E/AndroidRuntime(2104): FATAL EXCEPTION: main
07-08 03:51:02.986: E/AndroidRuntime(2104): Process: com.dev.camera, PID: 2104
07-08 03:51:02.986: E/AndroidRuntime(2104): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=0, result=-1, data=null} to activity {com.dev.camera/com.dev.camera.MainActivity}: java.lang.NullPointerException
07-08 03:51:02.986: E/AndroidRuntime(2104): at android.app.ActivityThread.deliverResults(ActivityThread.java:3365)
07-08 03:51:02.986: E/AndroidRuntime(2104): at android.app.ActivityThread.handleSendResult(ActivityThread.java:3408)
07-08 03:51:02.986: E/AndroidRuntime(2104): at android.app.ActivityThread.access$1300(ActivityThread.java:135)
07-08 03:51:02.986: E/AndroidRuntime(2104): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1244)
07-08 03:51:02.986: E/AndroidRuntime(2104): at android.os.Handler.dispatchMessage(Handler.java:102)
07-08 03:51:02.986: E/AndroidRuntime(2104): at android.os.Looper.loop(Looper.java:136)
07-08 03:51:02.986: E/AndroidRuntime(2104): at android.app.ActivityThread.main(ActivityThread.java:5017)
07-08 03:51:02.986: E/AndroidRuntime(2104): at java.lang.reflect.Method.invokeNative(Native Method)
07-08 03:51:02.986: E/AndroidRuntime(2104): at java.lang.reflect.Method.invoke(Method.java:515)
07-08 03:51:02.986: E/AndroidRuntime(2104): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
07-08 03:51:02.986: E/AndroidRuntime(2104): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
07-08 03:51:02.986: E/AndroidRuntime(2104): at dalvik.system.NativeStart.main(Native Method)
07-08 03:51:02.986: E/AndroidRuntime(2104): Caused by: java.lang.NullPointerException
07-08 03:51:02.986: E/AndroidRuntime(2104): at com.dev.camera.MainActivity.showPhoto(MainActivity.java:126)
07-08 03:51:02.986: E/AndroidRuntime(2104): at com.dev.camera.MainActivity.onActivityResult(MainActivity.java:95)
07-08 03:51:02.986: E/AndroidRuntime(2104): at android.app.Activity.dispatchActivityResult(Activity.java:5423)
07-08 03:51:02.986: E/AndroidRuntime(2104): at android.app.ActivityThread.deliverResults(ActivityThread.java:3361)
07-08 03:51:02.986: E/AndroidRuntime(2104): ... 11 more
07-08 03:51:08.536: I/Process(2104): Sending signal. PID: 2104 SIG: 9
答案 0 :(得分：0)
1）点击事件： Intent intent = new Intent（MediaStore.ACTION_IMAGE_CAPTURE）; startActivityForResult（intent，1）;
2）inActivityResult：
if ((requestCode == 1)) {
// -----------path getting from intent------------
String photoPath = null;
Cursor cursor = getContentResolver().query(
Media.EXTERNAL_CONTENT_URI,
new String[] { Media.DATA, Media.DATE_ADDED,MediaStore.Images.ImageColumns.ORIENTATION },
Media.DATE_ADDED, null, "date_added ASC");
if (cursor != null && cursor.moveToFirst()) {
do {
Uri uri = Uri.parse(cursor.getString(cursor .getColumnIndex(Media.DATA)));
photoPath = uri.toString();
} while (cursor.moveToNext());
cursor.close();
}
}
3）在你的清单中：