Question

ProgressChanged的定义：

// Summary:
// Event called whenever the progress of the upload changes.
public event Action<IUploadProgress> ProgressChanged;

public void insertFile(String filePath)
{
    //.. some code
    insertRequest.ProgressChanged += Upload_ProgressChanged;
}

public void Upload_ProgressChanged(Google.Apis.Upload.IUploadProgress progress)
{          
     //.. I need filePath from insertFile() here!
}

如何将其他参数传递给Upload_ProgressChanged？

我做了以下事情：

public void insertFile(String filePath)
{
    //.. some code
    ProgressChangedEventArgs args = new ProgressChangedEventArgs()
    {
        path = filePath
    };

    insertRequest.ProgressChanged += Upload_ProgressChanged;
}

static void Upload_ProgressChanged(object sender, ProgressChangedEventArgs e)
{

}

public class ProgressChangedEventArgs : EventArgs
{
    public string path { get; set; }
}

我错了Can not implicitly convert type 'void' to 'System.Action<Google.Apis.Upload.IUploadProgress>'

Answer 1

您可以在闭包中捕获变量

，而不是使用事件

insertRequest.ProgressChanges += progress => { /* Do something with filePath here */ };

Answer 2

首先，定义EventArgs类 - 这将让您拥有您喜欢的任何信息......

public class ProgressChgEventArgs : System.EventArgs
{
    public string Name { get;set; }
    public int InstanceId { get;set; }

    public ProgressChgEventArgs(string name, int id)
    {
        Name = name;
        InstanceId = id;
    }
}

接下来，创建使用这些参数的事件：

public event EventHandler<ProgressChgEventArgs> ProgressChanged;

然后，有一个＆＃39; On ....＆＃39;调用处理程序的方法

public void OnProgressChanged(ProgressChgEventArgs e)
{
    var handler = new EventHandler<ProgressChgEventArgs>();
    if (handler != null)
        handler(this, e);
}

现在，在代码中的相关点（可能是当进度发生变化时！），调用OnProgressChanged（），传入ProgressChgEventArgs的相应实例：

private void Progress(string caller, int callerId)
{
    var arguments = new ProgressChgEventArgs(caller, callerId);
    OnProgressChanged(arguments);
}

将其他参数传递给事件Action;

2 个答案: