图片显示
图片的显示应该都非常熟悉，场景很多，我先把我想的三个列举一下：
场景一：
从本地图片库选择图片进行显示：
?
async
private
void
LoadPictureByPicker()
{
FileOpenPicker fileOpen =
new
FileOpenPicker()
{
FileTypeFilter={
".jpg"
,
".jpeg"
,
".png"
,
".bmp"
},
ViewMode=PickerViewMode.Thumbnail,
SuggestedStartLocation=PickerLocationId.PicturesLibrary
};
bitmapImage =
new
BitmapImage();
storageFile = await fileOpen.PickSingleFileAsync();
if
(storageFile !=
null
)
{
using
(IRandomAccessStream stream = await storageFile.OpenAsync(FileAccessMode.Read))
{
bitmapImage.SetSource(stream);
}
}
img.Source = bitmapImage;
}
|
场景二：
直接请求网络URL
string url = "http://ww4.sinaimg.cn/bmiddle/8193c63ajw1ds3o5e56jaj.jpg";
方法一：
?
BitmapImage bitmapImage =
new
BitmapImage(
new
Uri(url));
img.Source = bitmapImage;
|
方法二：
?
async
private
void
LoadPictrueByUrl()
{
var rass = RandomAccessStreamReference.CreateFromUri(
new
Uri(url));
streamRandom = await rass.OpenReadAsync();
var bitmapImage =
new
BitmapImage();
bitmapImage.SetSource(streamRandom);
img.Source = bitmapImage;
}
|
若是简单的显示图片，用方法一就足够了，若需要保存图片，还是用方法二，因为方法一我目前还没有办法截取到它的流，除非再用HttpRequest请求一次;用方法二相对而言，就方便多了。
场景三：
显示项目文件中的图片
string url = "ms-appx:///images/flower.jpg";
方法一：
?
BitmapImage bitmapImage =
new
BitmapImage(
new
Uri(url));
img.Source = bitmapImage;
|
方法二：
?
async
private
void
LoadPictureByNative()
{
var rass = RandomAccessStreamReference.CreateFromUri(
new
Uri(url));
streamRandom = await rass.OpenReadAsync();
var bitmapImage =
new
BitmapImage();
bitmapImage.SetSource(streamRandom);
img.Source = bitmapImage;
}
|
原理与场景二是类似的
保存图片
保存图片也分两种情况
直接保存到图片库
?
StorageFolder folder = KnownFolders.PicturesLibrary;
storageFile = await folder.CreateFileAsync(
"sample.jpg"
, CreationCollisionOption.ReplaceExisting);
IBuffer buffer = RandomAccessStreamToBuffer(streamRandom);
await FileIO.WriteBufferAsync(storageFile, buffer);
|
RandomAccessStreamToBuffer是自定的转换方法,在前面流的转换中也已写了,这里再写一下吧..
?
private
IBuffer RandomAccessStreamToBuffer(IRandomAccessStream randomstream)
{
Stream stream = WindowsRuntimeStreamExtensions.AsStreamForRead(randomstream.GetInputStreamAt(0));
MemoryStream memoryStream =
new
MemoryStream();
if
(stream !=
null
)
{
byte
[] bytes = ConvertStreamTobyte(stream);
if
(bytes !=
null
)
{
var binaryWriter =
new
BinaryWriter(memoryStream);
binaryWriter.Write(bytes);
}
}
IBuffer buffer = WindowsRuntimeBufferExtensions.GetWindowsRuntimeBuffer(memoryStream, 0, (
int
)memoryStream.Length);
return
buffer;
}
public
static
byte
[] ConvertStreamTobyte(Stream input)
{
byte
[] buffer =
new
byte
[16 * 1024];
using
(MemoryStream ms =
new
MemoryStream())
{
int
read;
while
((read = input.Read(buffer, 0, buffer.Length)) > 0)
{
ms.Write(buffer, 0, read);
}
return
ms.ToArray();
}
}
|
显示保存文件对话框，可以自行选择保存路径，这时需用到FileSavePicker
?
FileSavePicker fileSave =
new
FileSavePicker();
fileSave.SuggestedSaveFile = storageFile;
fileSave.SuggestedStartLocation = PickerLocationId.Desktop;
fileSave.SuggestedFileName =
"test418"
;
fileSave.DefaultFileExtension =
".jpg"
;
fileSave.FileTypeChoices.Add(
"JPEG file"
,
new
List<
string
> {
".jpg"
});
StorageFile file = await fileSave.PickSaveFileAsync();
|
可能我上面的方法不是很简单方便，希望有更简捷的同胞可以共同分享下哈~
Trackback:
http://www.cnblogs.com/jing870812/archive/2012/04/19/2457805.html