将图像复制到另一个文件夹

Question

我正在使用 Xamaring 表单，我正在尝试将选定的图像路径复制到智能手机上的另一个位置，但无法正常工作。知道为什么以及如何解决它吗？

  private async Task btn_AddImg_ClickedAsync(object sender, EventArgs e)
        {
            var file = await CrossFilePicker.Current.PickFileAsync();
            if (file != null)
            {
                Error.IsVisible = true;
                Error.Text = file.FilePath;

                var dirToCreate = Path.Combine(Android.App.Application.Context.FilesDir.AbsolutePath, "WightLossPersonal");
                if (!Directory.Exists(dirToCreate))
                {

                    var x= Directory.CreateDirectory(dirToCreate);
                    System.IO.File.Copy(file.FilePath, dirToCreate, true);

                }
                else
                {
                   System.IO.File.Copy(file.FilePath, dirToCreate, true);
                }

            }
        }

在我的清单中我获得了权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

错误信息：

"/data/user/0/com.companyname.WightLoss/files/WightLossPersonal 是一个目录"

Answer 1

你的主要问题是你没有在新目录中传递文件名。所以这就像你试图复制目录本身，而不是文件！

基本上你必须将文件名与目录结合起来然后将其传递给 Copy() 方法。

string destFolder = Path.Combine(dirToCreate, file.Name);
System.IO.File.Copy(file.FilePath, destFolder , true);

但让我们让代码更简洁。我会评论代码以便更好地理解。

private async Task btn_AddImg_ClickedAsync(object sender, EventArgs e)
        {
            var file = await CrossFilePicker.Current.PickFileAsync();
            if (file != null)
            {
                Error.IsVisible = true;
                Error.Text = file.FilePath;

                var dirToCreate = Path.Combine(Android.App.Application.Context.FilesDir.AbsolutePath, "WightLossPersonal");
                if (!Directory.Exists(dirToCreate))
                {
                      Directory.CreateDirectory(dirToCreate);
                   // var x= Directory.CreateDirectory(dirToCreate); // don't need that variable x here since you don't want to use it later
                    //System.IO.File.Copy(file.FilePath, dirToCreate, true); No need here, will copy it in all ways down .

                }
                //else   // you don't need else, copy the file when finishing the check.
                //{

                  // Make a new path to compine the dir and the fileName
                   string destFolder = Path.Combine(dirToCreate, file.Name);
                   System.IO.File.Copy(file.FilePath, destFolder , true);
                //}

            }


  }

将图像复制到另一个文件夹

Copy image to another folder

c#

android

xamarin.forms

system.io.file