我想根据我输入的城市从我的firebase数据库中搜索用户列表

Question

我已经创建了一个献血申请表，我想根据我指定的血型和城市搜索捐赠者名单。

但无法做到这一点。

Answer 1

试试这个

    private readonly sendChunk = (file: File, progressModel: ProgressResponseModel): void => {
        const offset = progressModel.Offset;
        if (offset > file.size)
            throw new Error("Offset cannot be greater than the file size");

        const expectedSize = progressModel.ExpectedChunkSize;

        const blobChunk = file.slice(offset, expectedSize);

        const xhr = new XMLHttpRequest();
        xhr.onload = (ev: Event): void => {
             if (xhr.readyState === XMLHttpRequest.DONE && xhr.status === 200) {
                    const progress = this.progressFromText(xhr.responseText);

                    if (progress.Offset >= 0) {
                        this.sendChunk(file, progress);
                    }

                    console.log(`${progress.Progress} %`);
                }
            }

        xhr.open("POST", this._uploadChunkUrl, true);
        xhr.send(blobChunk);
    }