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首先，来自 /usr/share/vala/vapi/libarchive.vapi 的一些定义

[CCode (cprefix="ARCHIVE_", lower_case_cprefix="archive_", cheader_filename = "archive.h")]
namespace Archive {...
[CCode (instance_pos = 1.9, cname="archive_open_callback")]
    public delegate int OpenCallback (Archive archive);
    ...
    [CCode (cname = "struct archive", free_function="archive_write_finish")]
    public class Write : Archive {...
            public Result open (
                    [CCode (delegate_target_pos = 0.9)] OpenCallback ocb,
                    [CCode (delegate_target_pos = 0.9)] WriteCallback rcb,
                    [CCode (delegate_target_pos = 0.9)] CloseCallback ccb
            );
    }
}

然后我的代码

int mOpenCallback (Write archive)
{
    return Result.OK;
}

void foo(){...
Write archive = new Write();
archive.open(mOpenCallback,mWriteCallback,mCloseCallback);
...}

结果：错误：分配：无法从mOpenCallback' toArchive.OpenCallback 转换'

它出什么问题了 ？

然后我尝试了这个

namespace Archive {
int OpenCallback (Write archive)
{
    return Result.OK;
}
}

void foo(){...
Write archive = new Write();
archive.open(OpenCallback,mWriteCallback,mCloseCallback);
...}

但它输出： Archive' already contains a definition forOpenCallback'

void foo(){...
Write archive = new Write();
Archive.OpenCallback t = mOpenCallback;
archive.open(t,mWriteCallback,mCloseCallback);
...}

输出错误：分配：无法从foo.mOpenCallback' toArchive.OpenCallback 转换'

4

1 回答 1

1

mOpenCallbackhas 接受类型的参数Write，而不是Archive，因此它具有与委托不同的类型OpenCallback。如果您期望Write，您应该执行转换 fromArchive以在您的回调中写入。

于 2011-11-29T20:34:22.937 回答