/**
* * @param imagePath
* * 图像的路径
* * @param width
* * 指定输出图像的宽度
* * @param height
* * 指定输出图像的高度
* * @return 生成的缩略图
* */
public static Bitmap GetImageThumbnail(string imagePath, int width, int height)
{
Bitmap bitmap = null;
BitmapFactory.Options options = new BitmapFactory.Options();
options.InJustDecodeBounds = true;
// 获取这个图片的宽和高，注意此处的bitmap为null
bitmap = BitmapFactory.DecodeFile(imagePath, options);
options.InJustDecodeBounds = false; // 设为 false
// 计算缩放比
int h = options.OutHeight;
int w = options.OutWidth;
int beWidth = w / width;
int beHeight = h / height;
int be = 1;
if (beWidth < beHeight)
{
be = beWidth;
}
else
{
be = beHeight;
}
if (be <= 0)
{
be = 1;
}
options.InSampleSize = be;
// 重新读入图片，读取缩放后的bitmap，注意这次要把options.inJustDecodeBounds 设为 false
bitmap = BitmapFactory.DecodeFile(imagePath, options);
// 利用ThumbnailUtils来创建缩略图，这里要指定要缩放哪个Bitmap对象
bitmap = ThumbnailUtils.ExtractThumbnail(bitmap, width, height, ThumnailExtractOptions.RecycleInput);
return(bitmap);
}
public static float[] getPixels(Bitmap bitmap)
{
if (((bitmap.Width != IMAGE_SIZE) ||
(bitmap.Height != IMAGE_SIZE)))
{
// rescale the bitmap if needed
bitmap = ThumbnailUtils.ExtractThumbnail(bitmap, IMAGE_SIZE, IMAGE_SIZE);
}
int[] intValues = new int[(IMAGE_SIZE * IMAGE_SIZE)];
bitmap.GetPixels(intValues, 0, bitmap.Width, 0, 0, bitmap.Width, bitmap.Height);
float[] floatValues = new float[(IMAGE_SIZE
* (IMAGE_SIZE * 3))];
// Preprocess the image data from 0-255 int to normalized float based
// on the provided parameters.
for (int i = 0; (i < intValues.Length); i++)
{
int val = intValues[i];
floatValues[(i * 3)] = ((((val + 16)
& 255)
- IMAGE_MEAN)
/ IMAGE_STD);
floatValues[((i * 3)
+ 1)] = ((((val + 8)
& 255)
- IMAGE_MEAN)
/ IMAGE_STD);
floatValues[((i * 3)
+ 2)] = (((val & 255)
- IMAGE_MEAN)
/ IMAGE_STD);
}
return(floatValues);
}
/**
* * 获取视频的缩略图 先通过ThumbnailUtils来创建一个视频的缩略图，然后再利用ThumbnailUtils来生成指定大小的缩略图。
* * 如果想要的缩略图的宽和高都小于MICRO_KIND，则类型要使用MICRO_KIND作为kind的值，这样会节省内存。
* *
* * @param videoPath
* * 视频的路径
* * @param width
* * 指定输出视频缩略图的宽度
* * @param height
* * 指定输出视频缩略图的高度度
* * @param kind
* * 参照MediaStore.Images.Thumbnails类中的常量MINI_KIND和MICRO_KIND。
* * 其中，MINI_KIND: 512 x 384，MICRO_KIND: 96 x 96
* * @return 指定大小的视频缩略图
* */
public static Bitmap GetVideoThumbnail(String videoPath, int width, int height, ThumbnailKind kind)
{
Bitmap bitmap = null;
bitmap = ThumbnailUtils.CreateVideoThumbnail(videoPath, kind);
bitmap = ThumbnailUtils.ExtractThumbnail(bitmap, width, height, ThumnailExtractOptions.RecycleInput);
return(bitmap);
}
/// <summary>
/// Downscales a bitmap by the specified factor
/// </summary>
/// <returns>The bitmap.</returns>
/// <param name="wallpaper">Wallpaper.</param>
/// <param name="factor">Factor.</param>
public static Bitmap downscaleBitmap(Bitmap wallpaper, int factor)
{
// convert to bitmap and get the center
int widthPixels = wallpaper.Width / factor;
int heightPixels = wallpaper.Height / factor;
return(ThumbnailUtils.ExtractThumbnail(wallpaper, widthPixels, heightPixels));
}
protected override Bitmap Load(Android.Content.Context _context, long id)
{
var uri = IdToUri(id);
using (var inputStream = _context.ContentResolver.OpenInputStream(uri))
{
var bitmap = BitmapFactory.DecodeStream(inputStream, null, null);
Bitmap ThumbImage = ThumbnailUtils.ExtractThumbnail(bitmap, MinSide, MinSide);
bitmap.Recycle();
bitmap.Dispose();
return(ThumbImage);
}
}
public byte[] ResizeImage(byte[] imageBytes, int newWidth, int newHeight)
{
Byte[] NewByteArray = null;
// byte[] -> bitmap
using (var image = BitmapFactory.DecodeByteArray(imageBytes, 0, imageBytes.Length)) {
using (var bitmap = ThumbnailUtils.ExtractThumbnail(image, newWidth, newHeight)) {
// bitmap -> byte[]
MemoryStream stream = new MemoryStream();
bitmap.Compress(Bitmap.CompressFormat.Png, 0, stream);
NewByteArray = stream.ToArray();
}
}
return(NewByteArray);
}
public static Bitmap cropCenter(Bitmap bmp, int width = 160, int height = 120)
{
bool portrait = bmp.Width < bmp.Height;
if (portrait)
{
int x = width;
width = height;
height = x;
}
Bitmap result = null;
try
{
result = ThumbnailUtils.ExtractThumbnail(bmp, width, height);
}
catch (System.Exception)
{
}
return(result);
}
public static string CreateThumbnail(string sourceFile, int reqWidth, int reqHeight, string thumbnailPrefix = "")
{
var thumbnail = sourceFile.Replace(".jpg", $"_{thumbnailPrefix}thumb.jpg");
var source = sourceFile.LoadBitmap();
var target = ThumbnailUtils.ExtractThumbnail(source, reqWidth, reqHeight);
using (var outStream = System.IO.File.Create(thumbnail))
{
if (thumbnail.ToLower().EndsWith("png"))
{
target.Compress(Bitmap.CompressFormat.Png, 100, outStream);
}
else
{
target.Compress(Bitmap.CompressFormat.Jpeg, 95, outStream);
}
}
source.Recycle();
target.Recycle();
return(thumbnail);
}
static public async Task <ImageType> LoadPictureFromData(byte[] data, bool thumbnail)
{
Bitmap bmp = null;
if (thumbnail)
{
using (var stream = new MemoryStream(data))
{
using (var first = await BitmapFactory.DecodeStreamAsync(stream))
bmp = ThumbnailUtils.ExtractThumbnail(first, THUMBNAIL_WIDTH, THUMBNAIL_HEIGHT);
}
}
else
{
using (var stream = new MemoryStream(data))
bmp = await BitmapFactory.DecodeStreamAsync(stream);
}
if (bmp == null)
{
Insight.Track(string.Format("LoadPictureFromData returning NULL dataSize:{0}, thumbnail:{1}", data.Length, thumbnail));
}
return(bmp);
}
public static void GenerateImageThumbnail(string imageName, string thumbnailName, int width, int height, int type)
{
System.IO.FileStream os = null;
try
{
Bitmap bmp = null;
BitmapFactory.Options ops = new BitmapFactory.Options();
ops.InJustDecodeBounds = true;
bmp = BitmapFactory.DecodeFile(imageName, ops);
ops.InJustDecodeBounds = false;
// Computing Zooms in ratio
int outHeight = ops.OutHeight;
int outWidth = ops.OutWidth;
int widthPercent = outWidth / width;
int heightPercent = outHeight / height;
int sampleSize = 1;
if (widthPercent < heightPercent)
{
sampleSize = widthPercent;
}
else
{
sampleSize = heightPercent;
}
if (sampleSize <= 0)
{
sampleSize = 1;
}
ops.InSampleSize = sampleSize;
// Read the picture againand set options.inJustDecodeBounds to false.
bmp = BitmapFactory.DecodeFile(imageName, ops);
// Use ThumbnailUtils to create a thumbnail.
// The size of the thumbnail of the access control file on the server cannot exceed 8 times the size of the file.
// If the large thumbnail of some small images is generated by 1680*1920, the upload fails.
if (outHeight < height || outWidth < width)
{
bmp = ThumbnailUtils.ExtractThumbnail(bmp, outWidth, outHeight, ThumnailExtractOptions.RecycleInput);
}
else
{
bmp = ThumbnailUtils.ExtractThumbnail(bmp, width, height, ThumnailExtractOptions.RecycleInput);
}
string fileNameParent = thumbnailName.Substring(0, thumbnailName.LastIndexOf(Java.IO.File.Separator));
Java.IO.File file = new Java.IO.File(fileNameParent);
if (!file.Exists())
{
bool mkdirs = file.Mkdirs();
if (!mkdirs)
{
Log.Logger.Error(Tag, "getImageThumbnail file.mkdirs fail");
}
}
os = new FileStream(thumbnailName, FileMode.OpenOrCreate);
if (type == FileTypePng)
{
bmp.Compress(Bitmap.CompressFormat.Png, 90, os);
}
else
{
bmp.Compress(Bitmap.CompressFormat.Jpeg, 90, os);
}
}
catch (Java.IO.FileNotFoundException e)
{
Log.Logger.Error(Tag, "read or write file error");
}
catch (Exception e)
{
Log.Logger.Error(Tag, "internal error " + e.ToString());
}
finally
{
if (os != null)
{
try
{
os.Close();
}
catch (Exception e)
{
Log.Logger.Error(Tag, "close FileOutputStream error");
}
}
}
}
public static Bitmap LoadAndCropBitmap(this string fileName, int targetSize)
{
Bitmap theMap = LoadAndResizeBitmap(fileName, targetSize);
return(ThumbnailUtils.ExtractThumbnail(theMap, targetSize, targetSize));
}
public override void OnActivityResult(int requestCode, int resultCode, Intent data
)
{
base.OnActivityResult(requestCode, resultCode, data);
if (resultCode != ResultOk)
{
if (mCurrentTaskToAttachImage != null)
{
mCurrentTaskToAttachImage = null;
}
return;
}
if (requestCode == RequestTakePhoto)
{
mImageToBeAttached = BitmapFactory.DecodeFile(mImagePathToBeAttached);
// Delete the temporary image file
FilePath file = new FilePath(mImagePathToBeAttached);
file.Delete();
mImagePathToBeAttached = null;
}
else
{
if (requestCode == RequestChoosePhoto)
{
try
{
Uri uri = data.GetData();
mImageToBeAttached = MediaStore.Images.Media.GetBitmap(Activity.GetContentResolver
(), uri);
}
catch (IOException e)
{
Log.E(Application.Tag, "Cannot get a selected photo from the gallery.", e);
}
}
}
if (mImageToBeAttached != null)
{
if (mCurrentTaskToAttachImage != null)
{
try
{
Task.AttachImage(mCurrentTaskToAttachImage, mImageToBeAttached);
}
catch (CouchbaseLiteException e)
{
Log.E(Application.Tag, "Cannot attach an image to a task.", e);
}
}
else
{
// Attach an image for a new task
Bitmap thumbnail = ThumbnailUtils.ExtractThumbnail(mImageToBeAttached, ThumbnailSizePx
, ThumbnailSizePx);
ImageView imageView = (ImageView)Activity.FindViewById(Resource.Id.image);
imageView.SetImageBitmap(thumbnail);
}
}
// Ensure resetting the task to attach an image
if (mCurrentTaskToAttachImage != null)
{
mCurrentTaskToAttachImage = null;
}
}
public override global::Android.Views.View GetView(int position, global::Android.Views.View convertView
, ViewGroup parent)
{
if (convertView == null)
{
LayoutInflater inflater = (LayoutInflater)parent.GetContext().GetSystemService(Context
.LayoutInflaterService);
convertView = inflater.Inflate(Resource.Layout.view_task, null);
}
Couchbase.Lite.Document task = (Couchbase.Lite.Document) this.GetItem(position);
Bitmap image = null;
Bitmap thumbnail = null;
IList <Attachment> attachments = task.GetCurrentRevision().GetAttachments();
if (attachments != null && attachments.Count > 0)
{
Attachment attachment = attachments[0];
try
{
image = BitmapFactory.DecodeStream(attachment.GetContent());
thumbnail = ThumbnailUtils.ExtractThumbnail(image, MainActivity.TasksFragment.ThumbnailSizePx
, MainActivity.TasksFragment.ThumbnailSizePx);
}
catch (Exception e)
{
Log.E(Application.Tag, "Cannot decode the attached image", e);
}
}
Bitmap displayImage = image;
ImageView imageView = (ImageView)convertView.FindViewById(Resource.Id.image);
if (thumbnail != null)
{
imageView.SetImageBitmap(thumbnail);
}
else
{
imageView.SetImageDrawable(this._enclosing.GetResources().GetDrawable(Resource.Drawable.
ic_camera_light));
}
imageView.Click += async(sender, e) => {
if (displayImage != null)
{
DispatchImageViewIntent(displayImage);
}
else
{
AttachImage(task);
}
};
TextView text = (TextView)convertView.FindViewById(Resource.Id.text);
text.SetText((string)task.GetProperty("title"));
CheckBox checkBox = (CheckBox)convertView.FindViewById(Resource.Id.@checked);
bool checkedProperty = (bool)task.GetProperty("checked");
bool @checked = checkedProperty != null ? checkedProperty : false;
checkBox.SetChecked(@checked);
checkBox.Click += async(sender, e) => {
try
{
Task.UpdateCheckedStatus(task, checkBox.IsChecked());
}
catch (CouchbaseLiteException ex)
{
Log.E(((CouchbaseSample.Android.Application)Application).Tag, "Cannot update checked status", e);
}
};
return(convertView);
}