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
@Override
protected 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
@Override
protected 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。
