由系统提供的storagefile类提供的copy方法并没有提供可以提供显示进度的方法，在复制大文件时就会很不友好。
下面我提供一种显示进度的方法。
复制顾名思义，就是读取再写入。
所以我们通过storagefile读取文件流并写入另一个文件流。
在每一次读取时更新进度。
但是这有一个问题。根据不同缓存区的大小，这个东西不会太实时。如果用来获取速度，由于缓存区大小设置，获得的速度不准确。
有人说吧缓存区调小一点，我明确的告诉你，这个会影响拷贝的速度。
以下是具体代码
我创建了三个CopyFIle方法使可以支持文件夹
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| private async Task CopyFile(IStorageItem s1, StorageFolder s2)
{
RfileID = 0;
if (s1 is StorageFile s3)
{
await CopyFile(s3, s2);
}
else if (s1 is StorageFolder s4)
{
await CopyFile(s4, s2);
}
if (token)
{
CurrentCopyStatus = CopyStatus.paused;
return;
}
}
private async Task CopyFile(StorageFolder s1, StorageFolder s2)
{
var items = await s1.GetItemsAsync();
var s3 = await s2.CreateFolderAsync(s1.Name, CreationCollisionOption.OpenIfExists);
foreach (var item in items)
{
if (item is StorageFile file)
{
await CopyFile(file, s3);
}
else if (item is StorageFolder folder)
{
await CopyFile(folder, s3);
}
if (token)
{
CurrentCopyStatus = CopyStatus.paused;
return;
}
}
}
private async Task CopyFile(StorageFile s1, StorageFolder s2)
{
if (fileID > RfileID)
{
RfileID++;
}
else
{
CurrentFileName = s1.Name;
var size = Convert.ToDouble((await s1.GetBasicPropertiesAsync()).Size);
Fin = FinishFileSize;
using (var ReadStream = await s1.OpenAsync(FileAccessMode.Read))
{
using (var WriteStream = await (await s2.CreateFileAsync(s1.Name, CreationCollisionOption.ReplaceExisting)).OpenAsync(FileAccessMode.ReadWrite))
{
ulong Position = filePosion;
for (int i = 0; ; i++)
{
var buffer = new Windows.Storage.Streams.Buffer(BufferSize);
ReadStream.Seek(Position);
await ReadStream.ReadAsync(buffer, buffer.Capacity, InputStreamOptions.Partial);
WriteStream.Seek(Position);
Progress<uint> ip = new Progress<uint>(FileProgress);
await WriteStream.WriteAsync(buffer).AsTask(ip);
FinishFileSize += buffer.Capacity;
await WriteStream.FlushAsync();
Position = WriteStream.Position;
filePosion = Position;
if (buffer.Length < buffer.Capacity)
{
filePosion = 0;
break;
}
if (token)
{
CurrentCopyStatus = CopyStatus.paused;
return;
}
GC.Collect();
}
RfileID++;
fileID++;
}
}
}
}
|
其中以下代码通过用缓冲区获得Buffer再写入到文件，在写入后更新总共写入的文件字节。
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| using (var ReadStream = await s1.OpenAsync(FileAccessMode.Read))
{
using (var WriteStream = await (await s2.CreateFileAsync(s1.Name, CreationCollisionOption.ReplaceExisting)).OpenAsync(FileAccessMode.ReadWrite))
{
ulong Position = filePosion;
for (int i = 0; ; i++)
{
var buffer = new Windows.Storage.Streams.Buffer(BufferSize);
ReadStream.Seek(Position);
await ReadStream.ReadAsync(buffer, buffer.Capacity, InputStreamOptions.Partial);
WriteStream.Seek(Position);
await WriteStream.WriteAsync(buffer);
FinishFileSize += buffer.Capacity;
await WriteStream.FlushAsync();
Position = WriteStream.Position;
filePosion = Position;
if (buffer.Length < buffer.Capacity)//是buffer的容量，不是大小
{
filePosion = 0;
break;
}
if (token)
{
CurrentCopyStatus = CopyStatus.paused;
return;
}
GC.Collect();//清理
}
RfileID++;
fileID++;
}
}
|
然后在更新总写入字节数时根据之前算好的文件大小获得进度数据
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| public ulong FinishFileSize
{
get => _finishFileSize;
set { _finishFileSize = value; CurrentProgress = (double)value / AllFileSize * 100; OnPropertyChanged(); }
}
|
如果使用数据绑定到UI使用以下代码更新，注意相关类要继承INotifyPropertyChanged
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| #region 用于数据绑定更新
public event PropertyChangedEventHandler PropertyChanged = delegate { };
public async void OnPropertyChanged([CallerMemberName] string propertyName = null)
{
try
{
await CoreApplication.GetCurrentView().Dispatcher.AwaitableRunAsync(() =>
{
this.PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
});
}
catch (Exception)
{
}
}
#endregion
|
当然你可以设置计时器来计算copy的大致上的速度，这里不再描述。
