在React + Typescript中

时间:2018-09-19 09:16:20

标签: reactjs typescript

我有一个应用程序,需要集中精力处理输入内容,为此,我使用React ref

我有两个输入要移到一个单独的组件中。现在,它们看起来如下:

<input
  onChange={this.handleChangeOne}
  ref={refOne => (this.refOne = refOne as HTMLInputElement)}
  type="text"
/>
<input
  onChange={this.handleChangeTwo}
  ref={refTwo => (this.refTwo = refTwo as HTMLInputElement)}
  type="text"
/>

当涉及传递ref prop时,我很难使它们在单独的组件中工作。我已经尝试过这样的事情:

<InputBlock

          handleChangeOne={() => this.handleChangeOne}
          handleChangeTwo={() => this.handleChangeTwo}
          refOne=(refOne => (this.refOne = refOne as HTMLInputElement)}
          refTwo={refTwo => (this.refTwo = refTwo as HTMLInputElement)}
        />

以及组件本身

class InputBlock extends React.Component<IProps> {
  public render() {
    return (
      <React.Fragment>
        <input
          ref={refOne}
          onChange={handleChangeOne}
          type="text"
        />
        <input
          ref={refTwo}
          onChange={handleChangeTwo}
          type="text"
        />
      </React.Fragment>
    );
  }
}

export default InputBlock;

举例来说,我希望handleChangeOne专注于输入二,handleChangeTwo专注于输入一

1 个答案:

答案 0 :(得分:1)

我不知道您出了什么问题,但是以下这些对我有用:

    #Set the specified ID3v1 properties of a file by writing the last 128 bytes
    Function Set-ID3v1( #All parameters except path are optional, they will not change if not specified. 
      [string]$path, #Full path to the file to be updated - wildcards not supported because [] are so stinky and it's only supposed to work on one file at a time. 
      [string]$Title = "`0", #a string containing only 0 indicates a parameter not specified. 
      [string]$Artist  = "`0",
      [string]$Album = "`0",
      [string]$Year = "`0",
      [string]$Comment = "`0",
      [int]$Track = -1,
      [int]$Genre = -1, 
      [bool]$BackDate=$true){#Preserve modification date, but add a minute to indicate it's newer than duplicates
        $CurrentModified = (Get-ChildItem -LiteralPath $path).LastWriteTime #use literalpath here to get only one file, even if it has []
        Try{
            $enc = [System.Text.Encoding]::ASCII #Probably wrong, but works occasionally. See https://stackoverflow.com/questions/9857727/text-encoding-in-id3v2-3-tags
            $currentID3Bytes = New-Object byte[] (128)
            $strm = New-Object System.IO.FileStream ($path,[System.IO.FileMode]::Open,[System.IO.FileAccess]::ReadWrite,[System.IO.FileShare]::None)
            $strm.Seek(-128,'End') | Out-Null #Basic ID3v1 info is 128 bytes from EOF
            $strm.Read($currentID3Bytes,0,$currentID3Bytes.Length) | Out-Null
            Write-Host "$path `nCurrentID3: $($enc.GetString($currentID3Bytes))"
            $strm.Seek(-128,'End') | Out-Null #Basic ID3v1 info is 128 bytes from EOF
            If($enc.GetString($currentID3Bytes[0..2]) -ne  'TAG'){
                Write-Warning "No existing ID3v1 found - adding to end of file"
                $strm.Seek(0,'End') 
                $currentID3Bytes = $enc.GetBytes(('TAG' + (' ' * (30 + 30 + 30 + 4 + 30)))) #Add a blank tag to the end of the file
                $currentID3Bytes += 255 #empty Genre
                $strm.Write($currentID3Bytes,0,$currentID3Bytes.length)
                $strm.Flush()
                $Strm.Close()
                $strm = New-Object System.IO.FileStream ($path,[System.IO.FileMode]::Open,[System.IO.FileAccess]::Write,[System.IO.FileShare]::None)
                $strm.Seek(-128,'End') 
            } 
            $strm.Seek(3,'Current') | Out-Null #skip over 'TAG' to get to the good stuff
            If($Title -eq "`0"){ $strm.Seek(30,'Current') | Out-Null} #Skip over
             Else{ $strm.Write($enc.GetBytes($Title.PadRight(30,' ').Substring(0,30)),0,30)  } #if specified, write 30 space-padded bytes to the stream
            If($Artist -eq "`0"){ $strm.Seek(30,'Current') | Out-Null} 
             Else {$strm.Write($enc.GetBytes($Artist.PadRight(30,' ').Substring(0,30)),0,30) }
            If($Album -eq "`0"){ $strm.Seek(30,'Current') | Out-Null} 
             Else{$strm.Write($enc.GetBytes($Album.PadRight(30,' ').Substring(0,30)),0,30)  }
            If($Year -eq "`0"){ $strm.Seek(4,'Current') | Out-Null} 
             Else {$strm.Write($enc.GetBytes($Year.PadRight(4,' ').Substring(0,4)),0,4) }
            If(($Track -ne -1) -or ($currentID3Bytes[125] -eq 0)) {$CommentMaxLen = 28}Else{$CommentMaxLen = 30} #If a Track is specified or present in the file, Comment is 28 chars
            If($Comment -eq "`0"){ $strm.Seek($CommentMaxLen,'Current') | Out-Null} 
             Else {$strm.Write($enc.GetBytes($Comment.PadRight($CommentMaxLen,' ').Substring(0,$CommentMaxLen)),0,$CommentMaxLen)  }
            If($Track -eq -1 ){$strm.Seek(2,'Current') | Out-Null}
             Else{$strm.Write(@(0,$Track),0,2)} #Track, if present, is preceded by a 0-byte to form the last two bytes of Comment
            If($Genre -ne -1){$strm.Write($Genre,0,1) | Out-Null} 
        }Catch{
            Write-Error $_.Exception.Message
        }Finally{
            If($strm){
                $strm.Flush()
                $strm.Close()
            }
        }
        If($BackDate){(Get-ChildItem -LiteralPath $path).LastWriteTime = $CurrentModified.AddMinutes(1)}
    }