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MagneticStripeReader.ClaimReaderAsync 方法

定義

嘗試取得磁帶讀取器的獨佔存取權。

[Windows.Foundation.Metadata.RemoteAsync]
public IAsyncOperation<ClaimedMagneticStripeReader> ClaimReaderAsync();

傳回

當方法完成時,它會傳回 ClaimedMagneticStripeReader ,如果作業無法宣告磁條讀取器,則會傳回 null。

屬性

範例

// Claims the magnetic stripe reader for exclusive use
task<void> Scenario1::ClaimReader()
{
    
    return create_task(_reader->ClaimReaderAsync()).then([this] (ClaimedMagneticStripeReader^ claimedReader)
    {
        _claimedReader = claimedReader;
        if (_claimedReader != nullptr)
        {
            // UpdateReaderStatusTextBlock("Magnetic stripe reader claimed successfully.");		
        }
        else
        {
            // UpdateReaderStatusTextBlock("Failed to claim the magnetic stripe reader.");
        }
    });
}
// Claims the magnetic stripe reader for exclusive use.

private async Task<bool> ClaimReader()
{
    if (_claimedReader == null)
    {
        _claimedReader = await _reader.ClaimReaderAsync();

        if (_claimedReader != null)
        {
            // UpdateReaderStatusTextBlock("Magnetic stripe reader claimed successfully.");
        }
        else
        {
            // UpdateReaderStatusTextBlock("Failed to claim a magnetic stripe reader.");
            return false;
        }
    }
    return true;
}

適用於

產品 版本
WinRT Build 10240, Build 10586, Build 14383, Build 15063, Build 16299, Build 17134, Build 17763, Build 18362, Build 19041, Build 20348, Build 22000, Build 22621, Build 26100

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