在使用移动相机拍摄图像后尝试使用ImageView绘制图像时，我得到了致命的异常。但是我在使用Bitmap创建图像时遇到异常。
代码::
public class MMS extends Activity implements OnClickListener {
int TAKE_PHOTO_CODE = 0;
public static int count=0;
EditText preLoc,comeby;
Button ok,capture;
String photo;
String dir;
boolean GPS,flag;
String cityName=null;
String SubThorugh = null;
Intent i;
ImageView iv;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.mms);
preLoc = (EditText)findViewById(R.id.etPreLoc1);
comeby = (EditText)findViewById(R.id.etComing1);
iv = (ImageView)findViewById(R.id.ImageView1);
//ok = (Button)findViewById(R.id.bOK1);
capture = (Button) findViewById(R.id.btnCapture);
capture.setOnClickListener(this);
}
@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
switch(arg0.getId())
{
case R.id.btnCapture:
capturePicture();
break;
}
}
@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
super.onActivityResult(requestCode, resultCode, data);
if (requestCode == TAKE_PHOTO_CODE && resultCode == RESULT_OK) {
Log.d("CameraDemo", "Pic saved");
Toast.makeText(getApplicationContext(), "photo saved as: "+photo, Toast.LENGTH_LONG).show();
Bitmap photo = (Bitmap) data.getExtras().get("data");
iv.setImageBitmap(photo);
}
}
private void capturePicture() {
//here,we are making a folder named picFolder to store pics taken by the camera using this application
final String dir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES) + "/picFolder/";
File newdir = new File(dir);
newdir.mkdirs();
// here,counter will be incremented each time,and the picture taken by camera will be stored as 1.jpg,2.jpg and likewise.
count++;
String file = dir+count+".jpg";
photo = file;
File newfile = new File(file);
try {
newfile.createNewFile();
} catch (IOException e) {}
Uri outputFileUri = Uri.fromFile(newfile);
Intent cameraIntent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
cameraIntent.putExtra(MediaStore.EXTRA_OUTPUT, outputFileUri);
startActivityForResult(cameraIntent, TAKE_PHOTO_CODE);
}
}
和例外是：
06-04 22:15:46.515: W/dalvikvm(22711): threadid=1: thread exiting with uncaught exception (group=0x40018578)
06-04 22:15:46.546: E/AndroidRuntime(22711): FATAL EXCEPTION: main
06-04 22:15:46.546: E/AndroidRuntime(22711): java.lang.RuntimeException: Failure delivering result ResultInfo{who=null, request=0, result=-1, data=null} to activity {com.example.nirbhaya/com.example.nirbhaya.MMS}: java.lang.NullPointerException
06-04 22:15:46.546: E/AndroidRuntime(22711): at android.app.ActivityThread.deliverResults(ActivityThread.java:2536)
06-04 22:15:46.546: E/AndroidRuntime(22711): at android.app.ActivityThread.handleSendResult(ActivityThread.java:2578)
06-04 22:15:46.546: E/AndroidRuntime(22711): at android.app.ActivityThread.access$2000(ActivityThread.java:117)
06-04 22:15:46.546: E/AndroidRuntime(22711): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:965)
06-04 22:15:46.546: E/AndroidRuntime(22711): at android.os.Handler.dispatchMessage(Handler.java:99)
06-04 22:15:46.546: E/AndroidRuntime(22711): at android.os.Looper.loop(Looper.java:130)
06-04 22:15:46.546: E/AndroidRuntime(22711): at android.app.ActivityThread.main(ActivityThread.java:3687)
06-04 22:15:46.546: E/AndroidRuntime(22711): at java.lang.reflect.Method.invokeNative(Native Method)
06-04 22:15:46.546: E/AndroidRuntime(22711): at java.lang.reflect.Method.invoke(Method.java:507)
06-04 22:15:46.546: E/AndroidRuntime(22711): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
06-04 22:15:46.546: E/AndroidRuntime(22711): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)
06-04 22:15:46.546: E/AndroidRuntime(22711): at dalvik.system.NativeStart.main(Native Method)
06-04 22:15:46.546: E/AndroidRuntime(22711): Caused by: java.lang.NullPointerException
06-04 22:15:46.546: E/AndroidRuntime(22711): at com.example.nirbhaya.MMS.onActivityResult(MMS.java:125)
06-04 22:15:46.546: E/AndroidRuntime(22711): at android.app.Activity.dispatchActivityResult(Activity.java:3908)
06-04 22:15:46.546: E/AndroidRuntime(22711): at android.app.ActivityThread.deliverResults(ActivityThread.java:2532)
06-04 22:15:46.546: E/AndroidRuntime(22711): ... 11 more
06-04 22:15:46.921: D/dalvikvm(22711): GC_CONCURRENT freed 268K, 48% free 2956K/5639K, external 583K/945K, paused 3ms+4ms
第125行的代码是 位图照片=（位图）data.getExtras（）。get（“data”）;
答案 0 :(得分：0)
调用者可以传递额外的EXTRA_OUTPUT来控制该图像的写入位置。如果EXTRA_OUTPUT不存在，则在额外字段中返回小尺寸图像作为Bitmap对象。这对于只需要小图像的应用程序非常有用。如果存在EXTRA_OUTPUT，则将将全尺寸图像写入EXTRA_OUTPUT的Uri值。
这意味着如果你设置了EXTRA_OUTPUT参数，它就不会在额外字段中返回一个Bitmap对象 - 它只会将全尺寸图像写入指定的Uri。
答案 1 :(得分：0)
我同意詹姆斯的答案是正确的，因此您必须直接从存储它的路径中选择图像，路径将是
String path = newfile.getAbsolutePath（）; 然后你可以使用这个函数从该路径创建位图，该函数将path作为参数并返回位图。
public Bitmap getImage1(String path) throws IOException
{
BitmapFactory.Options options = new BitmapFactory.Options();
options.inJustDecodeBounds = true;
BitmapFactory.decodeFile(path, options);
int srcWidth = options.outWidth;
int srcHeight = options.outHeight;
int[] newWH = new int[2];
newWH[0] = srcWidth/2;
newWH[1] = (newWH[0]*srcHeight)/srcWidth;
int inSampleSize = 1;
while(srcWidth / 2 >= newWH[0]){
srcWidth /= 2;
srcHeight /= 2;
inSampleSize *= 2;
}
options.inJustDecodeBounds = false;
options.inDither = false;
options.inSampleSize = inSampleSize;
options.inScaled = false;
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
Bitmap sampledSrcBitmap = BitmapFactory.decodeFile(path,options);
ExifInterface exif = new ExifInterface(path);
String s=exif.getAttribute(ExifInterface.TAG_ORIENTATION);
System.out.println("Orientation>>>>>>>>>>>>>>>>>>>>"+s);
Matrix matrix = new Matrix();
float rotation = rotationForImage(con, Uri.fromFile(new File(path)));
if (rotation != 0f) {
matrix.preRotate(rotation);
}
Bitmap pqr=Bitmap.createBitmap(
sampledSrcBitmap, 0, 0, sampledSrcBitmap.getWidth(), sampledSrcBitmap.getHeight(), matrix, true);
return pqr;
}
public float rotationForImage(Context context, Uri uri) {
if (uri.getScheme().equals("content")) {
String[] projection = { Images.ImageColumns.ORIENTATION };
Cursor c = context.getContentResolver().query(
uri, projection, null, null, null);
if (c.moveToFirst()) {
return c.getInt(0);
}
} else if (uri.getScheme().equals("file")) {
try {
ExifInterface exif = new ExifInterface(uri.getPath());
int rotation = (int)exifOrientationToDegrees(
exif.getAttributeInt(ExifInterface.TAG_ORIENTATION,
ExifInterface.ORIENTATION_NORMAL));
return rotation;
} catch (IOException e) {
e.printStackTrace();
}catch (Exception e) {
e.printStackTrace();
}
}
return 0f;
}
private static float exifOrientationToDegrees(int exifOrientation) {
if (exifOrientation == ExifInterface.ORIENTATION_ROTATE_90) {
return 90;
} else if (exifOrientation == ExifInterface.ORIENTATION_ROTATE_180) {
return 180;
} else if (exifOrientation == ExifInterface.ORIENTATION_ROTATE_270) {
return 270;
}
return 0;
}
}
其他功能用于为图像提供正确的方向。