React Native Alert 功能不会触发

React Native Alert function won't triggered

我只是想做一个简单的教程来学习。我只是对授权进行编码以查看警告框,但我不能 运行。另外,我正在浏览器的 webview 中对其进行测试。

这是我的代码。

        console.log('pressed');
        console.log(this.state.mail);
        console.log(this.state.password);
        if (this.state.mail == 'test' && this.state.password == 123) {
            console.log("successful");
        }
        else {
            Alert.alert(
                "Alert Title",
                "My Alert Msg",
                [
                  {
                    text: "Cancel",
                    onPress: () => console.log("Cancel Pressed"),
                    style: "cancel"
                  },
                  { text: "OK", onPress: () => console.log("OK Pressed") }
                ]
              );
            console.log("failed");
        }
    }```

If part works correctly. In else part 'failed' log also works correctly but alert won't work. 

据我搜索,React 本机警报组件无法在网络浏览器上运行。我用我的手机 phone 测试了它,发现它有效。