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Android开发实现ImageView加载摄像头拍摄的大图功能

2019-12-12 01:43:06
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本文实例讲述了Android开发实现ImageView加载摄像头拍摄的大图功能。分享给大家供大家参考,具体如下:

这个方法是从官方demo中摘录的,在此记录学习。

权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" /><uses-feature  android:name="android.hardware.camera2"  android:required="false" />

另:关于权限控制还可参考:Android Manifest功能与权限描述大全

设置变量保存文件存储路径

private String mCurrentPhotoPath;/*** 拍照flag*/private static final int REQUEST_IMAGE_CAPTURE_O = 2;

创建存储路径及文件名

 /*** 创建拍摄的图片的存储路径及文件名* @return* @throws IOException*/private File createImageFile() throws IOException{  String timeStamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());  String imageFileName = "JPEG_" + timeStamp + "_";  File storageDir = Environment.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES);  Log.d("TrainingFirstActivity", "storageDir:" + storageDir);  File image = File.createTempFile(imageFileName, ".jpg", storageDir);  mCurrentPhotoPath = image.getAbsolutePath();  Log.d("image.getAbsolutePath()", image.getAbsolutePath() + "");  return image;}

拍摄图片并保存

Intent takePictureOintent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);if (takePictureOintent.resolveActivity(getPackageManager()) != null){ File photoFile = null; try {  photoFile = createImageFile(); } catch (IOException e) {  e.printStackTrace(); } if (photoFile != null){  takePictureOintent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(photoFile));  startActivityForResult(takePictureOintent, REQUEST_IMAGE_CAPTURE_O); }}

处理并压缩拍照结果,takePhotoThenToShowImg是一个ImageView控件

@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {  if (requestCode == REQUEST_IMAGE_CAPTURE_O && resultCode == RESULT_OK){   int targetW = takePhotoThenToShowImg.getWidth();   int targetH = takePhotoThenToShowImg.getHeight();  /* Get the size of the image */   BitmapFactory.Options bmOptions = new BitmapFactory.Options();   bmOptions.inJustDecodeBounds = true;   BitmapFactory.decodeFile(mCurrentPhotoPath, bmOptions);   int photoW = bmOptions.outWidth;   int photoH = bmOptions.outHeight;  /* Figure out which way needs to be reduced less */   int scaleFactor = 1;   if ((targetW > 0) || (targetH > 0)) {    scaleFactor = Math.min(photoW/targetW, photoH/targetH);   }  /* Set bitmap options to scale the image decode target */   bmOptions.inJustDecodeBounds = false;   bmOptions.inSampleSize = scaleFactor;   bmOptions.inPurgeable = true;  /* Decode the JPEG file into a Bitmap */   Bitmap bitmap = BitmapFactory.decodeFile(mCurrentPhotoPath, bmOptions);  /* Associate the Bitmap to the ImageView */   takePhotoThenToShowImg.setImageBitmap(bitmap);   galleryAddPic();  }}

最后可以将拍摄到的照片添加到Media Provider的数据库中,以便图库或者其他程序读取照片

/*** 将拍摄到的照片添加到Media Provider的数据库中*/private void galleryAddPic(){  Intent mediaScanIntent = new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE);  File f = new File(mCurrentPhotoPath);  Uri contentUri = Uri.fromFile(f);  mediaScanIntent.setData(contentUri);  this.sendBroadcast(mediaScanIntent);}

如果只需要缩略图的话,只要调摄像头拍摄直接处理结果就行

@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) { if (requestCode == REQUEST_IMAGE_CAPTURE && resultCode == RESULT_OK){//展示图片   Bundle extras = data.getExtras();   Bitmap imageBitmap = (Bitmap) extras.get("data");   takePhotoThenToShowImg.setImageBitmap(imageBitmap);  }}

更多关于Android相关内容感兴趣的读者可查看本站专题:《Android拍照与图片处理技巧总结》、《Android图形与图像处理技巧总结》、《Android开发入门与进阶教程》、《Android调试技巧与常见问题解决方法汇总》、《Android基本组件用法总结》、《Android视图View技巧总结》、《Android布局layout技巧总结》及《Android控件用法总结

希望本文所述对大家Android程序设计有所帮助。

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