在ReactJS中，组件在收到Fetch响应后不会重新渲染。因此，总是在屏幕上看到“正在加载PDF ...”消息
componentDidMount代码如下，
fread()获取后，不会打印getData值（数据）。由于未重新渲染此组件，因此未设置pdfData。同时，数组值会打印在getData（）中。
使用react-pdf库将返回的数据呈现为pdf
data.tablegetData在下面给出，
A <- data.table::fread("
Position phaseGroup phaseGroup_2 phaseGroup_3 Synonymous Information Phasing Pha_Syn Grouped yPos
5.85E+04 1 1 1 16 1.1 Phased Phased-16 1 1
5.96E+04 1 1 1 16 1.1 Phased Phased-16 1 2
6.22E+04 1 1 1 16 1.1 Phased Phased-16 1 3
6.26E+04 1 1 1 16 1.1 Phased Phased-16 1 4
7.22E+04 NA 1 1 16 1.NA Unphased Unphased-16 1 5
7.30E+04 1 1 1 16 1.1 Phased Phased-16 1 6
2.03E+05 2 2 2.1 16 1.2 Phased Phased-16 1 7
2.48E+05 2 2 2.1 1 1.2 Phased Phased-1 1 8
2.53E+05 2 2 2.1 16 1.2 Phased Phased-16 1 9
2.53E+05 2 2 2.1 16 1.2 Phased Phased-16 1 10
2.54E+05 2 2 2.1 16 1.2 Phased Phased-16 1 11
2.54E+05 2 2 2.1 16 1.2 Phased Phased-16 1 12
2.54E+05 NA 2 2.2 16 1.NA Unphased Unphased-16 1 13
2.55E+05 2 2 2.2 16 1.2 Phased Phased-16 1 14
2.56E+05 2 2 2.2 16 1.2 Phased Phased-16 1 15
2.58E+05 2 2 2.2 16 1.2 Phased Phased-16 1 16
2.61E+05 2 2 2.2 16 1.2 Phased Phased-16 1 17
5.76E+05 3 3 3.1 16 1.3 Phased Phased-16 1 18
5.77E+05 3 3 3.1 16 1.3 Phased Phased-16 1 19
5.77E+05 3 3 3.1 16 1.3 Phased Phased-16 1 20
5.79E+05 3 3 3.1 16 1.3 Phased Phased-16 1 21
6.22E+05 3 3 3.1 16 1.3 Phased Phased-16 1 22
6.23E+05 3 3 3.1 1 1.3 Phased Phased-1 1 23
6.24E+05 3 3 3.2 16 1.3 Phased Phased-16 1 24
6.25E+05 3 3 3.2 16 1.3 Phased Phased-16 1 25
6.26E+05 3 3 3.2 16 1.3 Phased Phased-16 1 26
6.27E+05 3 3 3.2 16 1.3 Phased Phased-16 1 27
6.29E+05 3 3 3.2 16 1.3 Phased Phased-16 1 28
6.29E+05 3 3 3.2 16 1.3 Phased Phased-16 1 29
6.31E+05 3 3 3.3 16 1.3 Phased Phased-16 1 30
6.32E+05 3 3 3.3 16 1.3 Phased Phased-16 1 31
6.32E+05 3 3 3.3 16 1.3 Phased Phased-16 1 32
6.34E+05 3 3 3.3 16 1.3 Phased Phased-16 1 33
6.35E+05 3 3 3.3 16 1.3 Phased Phased-16 1 34
6.37E+05 3 3 3.3 16 1.3 Phased Phased-16 1 35
6.76E+05 3 3 3.4 16 1.3 Phased Phased-16 1 36
6.82E+05 3 3 3.4 16 1.3 Phased Phased-16 1 37
7.40E+05 3 3 3.4 16 1.3 Phased Phased-16 1 38
7.57E+05 3 3 3.4 16 1.3 Phased Phased-16 1 39
7.60E+05 3 3 3.4 16 1.3 Phased Phased-16 1 40
7.61E+05 3 3 3.4 16 1.3 Phased Phased-16 1 41
7.61E+05 3.5 3.5 3.5 16 2.1 Phased Phased-16 2 41.5
2.03E+06 4 4 4 16 3.4 Phased Phased-16 3 42
2.10E+06 4 4 4 1 3.4 Phased Phased-1 3 43
2.15E+06 4 4 4 16 3.4 Phased Phased-16 3 44
2.16E+06 4 4 4 16 3.4 Phased Phased-16 3 45
2.16E+06 4 4 4 16 3.4 Phased Phased-16 3 46
2.16E+06 4 4 4 16 3.4 Phased Phased-16 3 47
2.17E+06 4 4 4 1 3.4 Phased Phased-1 3 48
2.18E+06 NA 4 4 1 3.NA Unphased Unphased-1 3 49
2.36E+06 5 5 5 16 3.5 Phased Phased-16 3 50
2.36E+06 5 5 5 16 3.5 Phased Phased-16 3 51
2.37E+06 5 5 5 16 3.5 Phased Phased-16 3 52
2.37E+06 5 5 5 1 3.5 Phased Phased-1 3 53
2.37E+06 5 5 5 1 3.5 Phased Phased-1 3 54
2.37E+06 5 5 5 16 3.5 Phased Phased-16 3 55
2.37E+06 5 5 5 16 3.5 Phased Phased-16 3 56
2.37E+06 5 5 5 1 3.5 Phased Phased-1 3 57
2.50E+06 5 5 5 16 3.5 Phased Phased-16 3 58
2.50E+06 5 5 5 16 3.5 Phased Phased-16 3 59
2.53E+06 5 5 5 1 3.5 Phased Phased-1 3 60
2.54E+06 5 5 5 16 3.5 Phased Phased-16 3 61
2.54E+06 5 5 5 1 3.5 Phased Phased-1 3 62
2.56E+06 5 5 5 16 3.5 Phased Phased-16 3 63
2.60E+06 5 5 5 16 3.5 Phased Phased-16 3 64
2.62E+06 5 5 5 16 3.5 Phased Phased-16 3 65
3.04E+06 NA 5 5 1 4.NA Unphased Unphased-1 4 66
3.17E+06 NA 5 5 1 4.NA Unphased Unphased-1 4 67
3.84E+06 NA 5 5 16 4.NA Unphased Unphased-16 4 68
4.00E+06 6 6 6 16 5.6 Phased Phased-16 5 69
4.00E+06 6 6 6 16 5.6 Phased Phased-16 5 70
4.00E+06 6 6 6 16 5.6 Phased Phased-16 5 71
4.00E+06 6 6 6 1 5.6 Phased Phased-1 5 72
4.00E+06 6 6 6 16 5.6 Phased Phased-16 5 73
4.00E+06 NA 6 6 16 5.NA Unphased Unphased-16 5 74
4.00E+06 NA 6 6 16 5.NA Unphased Unphased-16 5 75
4.00E+06 7 7 7 16 5.7 Phased Phased-16 5 76
4.00E+06 7 7 7 16 5.7 Phased Phased-16 5 77
4.00E+06 7 7 7 1 5.7 Phased Phased-1 5 78
4.00E+06 7 7 7 1 5.7 Phased Phased-1 5 79
4.00E+06 7 7 7 16 5.7 Phased Phased-16 5 80
4.00E+06 7 7 7 16 5.7 Phased Phased-16 5 81
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 82
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 83
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 84
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 85
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 86
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 87
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 88
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 89
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 90
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 91
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 92
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 93
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 94
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 95
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 96
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 97
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 98
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 99
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 100
4.00E+06 8 8 8 16 5.8 Phased Phased-16 5 101
4.01E+06 8 8 8 16 5.8 Phased Phased-16 5 102
4.01E+06 8 8 8 16 5.8 Phased Phased-16 5 103
4.01E+06 9 9 9 16 5.9 Phased Phased-16 5 104
4.01E+06 9 9 9 16 5.9 Phased Phased-16 5 105
4.01E+06 NA 9 9 16 5.NA Unphased Unphased-16 5 106
4.01E+06 9 9 9 16 5.9 Phased Phased-16 5 107
4.01E+06 9 9 9 16 5.9 Phased Phased-16 5 108
4.01E+06 9 9 9 16 5.9 Phased Phased-16 5 109
4.01E+06 9 9 9 16 5.9 Phased Phased-16 5 110
4.01E+06 9 9 9 16 5.9 Phased Phased-16 5 111
4.01E+06 9 9 9 16 5.9 Phased Phased-16 5 112
4.01E+06 9 9 9 16 5.9 Phased Phased-16 5 113
4.01E+06 9 9 9 16 5.9 Phased Phased-16 5 114
4.01E+06 9 9 9 16 5.9 Phased Phased-16 5 115
4.01E+06 9 9 9 16 5.9 Phased Phased-16 5 116
4.01E+06 9 9 9 16 5.9 Phased Phased-16 5 117
4.01E+06 9 9 9 16 5.9 Phased Phased-16 5 118
4.01E+06 NA 9 9 1 5.NA Unphased Unphased-1 5 119
4.02E+06 9 9 9 16 5.9 Phased Phased-16 5 120
4.02E+06 10 10 10 1 5.1 Phased Phased-1 5 121
4.02E+06 10 10 10 16 5.1 Phased Phased-16 5 122
4.02E+06 NA 10 10 1 5.NA Unphased Unphased-1 5 123
4.02E+06 10 10 10 16 5.1 Phased Phased-16 5 124
4.02E+06 10 10 10 16 5.1 Phased Phased-16 5 125
4.02E+06 10 10 10 1 5.1 Phased Phased-1 5 126
4.02E+06 10 10 10 1 5.1 Phased Phased-1 5 127
4.02E+06 10 10 10 1 5.1 Phased Phased-1 5 128
4.02E+06 NA 10 10 1 5.NA Unphased Unphased-1 5 129
4.02E+06 10 10 10 1 5.1 Phased Phased-1 5 130
4.02E+06 10 10 10 1 5.1 Phased Phased-1 5 131
4.02E+06 10 10 10 16 5.1 Phased Phased-16 5 132
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 133
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 134
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 135
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 136
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 137
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 138
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 139
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 140
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 141
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 142
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 143
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 144
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 145
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 146
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 147
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 148
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 149
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 150
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 151
4.03E+06 NA 10 10 16 5.NA Phased Phased-16 5 152
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 153
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 154
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 155
4.03E+06 10 10 10 16 5.1 Phased Phased-16 5 156
4.04E+06 10 10 10 16 5.1 Phased Phased-16 5 157
4.04E+06 10 10 10 1 5.1 Phased Phased-1 5 158
4.04E+06 10 10 10 1 5.1 Phased Phased-1 5 159
4.04E+06 10 10 10 1 5.1 Phased Phased-1 5 160
4.04E+06 10 10 10 16 5.1 Phased Phased-16 5 161
4.04E+06 10 10 10 16 5.1 Phased Phased-16 5 162
4.04E+06 NA 10 10 16 5.NA Unphased Unphased-16 5 163
4.04E+06 NA 10 10 16 5.NA Unphased Unphased-16 5 164
4.04E+06 10 10 10 16 5.1 Phased Phased-16 5 165
4.04E+06 NA 10 10 16 5.NA Unphased Unphased-16 5 166
4.04E+06 10 10 10 16 5.1 Phased Phased-16 5 167
4.04E+06 10 10 10 1 5.1 Phased Phased-1 5 168
4.04E+06 10 10 10 1 5.1 Phased Phased-1 5 169
4.04E+06 10 10 10 1 5.1 Phased Phased-1 5 170
4.04E+06 10 10 10 16 5.1 Phased Phased-16 5 171
4.04E+06 10 10 10 1 5.1 Phased Phased-1 5 172
4.04E+06 NA 10 10 16 5.NA Unphased Unphased-16 5 173
4.04E+06 10 10 10 16 5.1 Phased Phased-16 5 174
4.04E+06 10 10 10 16 5.1 Phased Phased-16 5 175
4.04E+06 NA 10 10 16 5.NA Unphased Unphased-16 5 176
4.04E+06 10 10 10 16 5.1 Phased Phased-16 5 177
4.04E+06 10 10 10 1 5.1 Phased Phased-1 5 178
4.04E+06 10 10 10 1 5.1 Phased Phased-1 5 179
4.04E+06 10 10 10 16 5.1 Phased Phased-16 5 180
4.04E+06 10 10 10 16 5.1 Phased Phased-16 5 181
4.04E+06 10 10 10 1 5.1 Phased Phased-1 5 182
4.04E+06 10 10 10 16 5.1 Phased Phased-16 5 183
4.04E+06 10 10 10 16 5.1 Phased Phased-16 5 184
4.04E+06 10 10 10 16 5.1 Phased Phased-16 5 185
4.04E+06 NA 10 10 16 5.NA Unphased Unphased-16 5 186
4.04E+06 10 10 10 16 5.1 Phased Phased-16 5 187
4.05E+06 10 10 10 16 5.1 Phased Phased-16 5 188
4.05E+06 10 10 10 16 5.1 Phased Phased-16 5 189
4.05E+06 10 10 10 16 5.1 Phased Phased-16 5 190
4.05E+06 10 10 10 1 5.1 Phased Phased-1 5 191
4.05E+06 10 10 10 16 5.1 Phased Phased-16 5 192
4.05E+06 10 10 10 16 5.1 Phased Phased-16 5 193
4.05E+06 10 10 10 16 5.1 Phased Phased-16 5 194
4.05E+06 10 10 10 16 5.1 Phased Phased-16 5 195
4.05E+06 10 10 10 1 5.1 Phased Phased-1 5 196
4.05E+06 10 10 10 1 5.1 Phased Phased-1 5 197
4.05E+06 10 10 10 1 5.1 Phased Phased-1 5 198
4.05E+06 10 10 10 1 5.1 Phased Phased-1 5 199
4.05E+06 10 10 10 1 5.1 Phased Phased-1 5 200
4.05E+06 10 10 10 1 5.1 Phased Phased-1 5 201
4.05E+06 10 10 10 1 5.1 Phased Phased-1 5 202
4.05E+06 10 10 10 1 5.1 Phased Phased-1 5 203
4.05E+06 10 10 10 1 5.1 Phased Phased-1 5 204
4.05E+06 10 10 10 16 5.1 Phased Phased-16 5 205
4.05E+06 10 10 10 1 5.1 Phased Phased-1 5 206
4.05E+06 10 10 10 1 5.1 Phased Phased-1 5 207
4.05E+06 10 10 10 1 5.1 Phased Phased-1 5 208
4.59E+06 NA 10 10 16 5.NA Unphased Unphased-16 5 209")
答案 0 :(得分：2)
由于您的getData函数为async，因此您需要在await中将componentDidMount的结果或根据诺言行事（假设您已经{{1} } ing您的API调用）。例如：
正在等待：
await或承诺：
async componentDidMount() {
const { getData } = this.props;
let data = await getData(); // <-- Await the async here
this.setState({ pdfData: data });
}