将base64 PDF保存到缓存目录，并使用系统默认的PDF阅读器打开它

Question

我有一个base64 PDF字符串，需要将其保存到一个文件中，以便在系统（android或ios）上打开它，我希望它位于缓存的目录中，因为在大多数情况下它只是一次性视图。

但是当我尝试通过链接打开文件时，世博会（或者可能是android）给了我关于“意图”的错误

我正在使用博览会

我收到的错误消息是：

[Error: Could not open URL 'file:///data/user/0/host.exp.exponent/cache/Despacho%20-%2000043651620108260142.pdf': file:///data/user/0/host.exp.exponent/cache/Despacho%20-%2000043651620108260142.pdf exposed beyond app through Intent.getData()]

我正在使用此函数保存并打开文件，但除了我收到的错误之外没有任何反应：

async function saveAndOpenFile(fileName: string, content: string) {
    try {
        let directoryUri = FileSystem.cacheDirectory + fileName;
        console.log("D", directoryUri);

        const writed = await FileSystem.writeAsStringAsync(directoryUri, content, { encoding: FileSystem.EncodingType.Base64 });
        console.log("W", writed);

        await Linking.openURL(directoryUri);
    } catch (error) {
        Alert.alert("Ocorreu um erro", "Não foi possível abrir o documento");
        console.log(error);
    }
}

我的控制台输出是：

 LOG  D file:///data/user/0/host.exp.exponent/cache/Despacho%20-%2000043651620108260142.pdf
 LOG  W null
 LOG  [Error: Could not open URL 'file:///data/user/0/host.exp.exponent/cache/Despacho%20-%2000043651620108260142.pdf': file:///data/user/0/host.exp.exponent/cache/Despacho%20-%2000043651620108260142.pdf exposed beyond app through Intent.getData()]

Answer 1

我通过这样做找到了解决方案：

const [viewUri, setViewUri] = React.useState<string | null>(null);

async function saveAndOpenFile(fileName: string, content: string) {
    try {
        let fileUri = FileSystem.documentDirectory + fileName;
        await FileSystem.writeAsStringAsync(fileUri, content, { encoding: FileSystem.EncodingType.Base64 });

        const cUri = await FileSystem.getContentUriAsync(fileUri);

        if (Platform.OS === "android") {
            await IntentLauncher.startActivityAsync("android.intent.action.VIEW", {
                data: cUri,
                flags: 1,
                type: "application/pdf",
            });

            console.log("CLOSING NOW");
            closeModal();
        } else {
            setViewUri(cUri); // Set as variable to display a webview below
        }
    } catch (error) {
        Alert.alert("Ocorreu um erro", "Não foi possível abrir o documento");
        console.log(error);
    }
}

return (
    <WebView
        allowFileAccess
        allowFileAccessFromFileURLs
        allowUniversalAccessFromFileURLs
        scalesPageToFit
        mixedContentMode={Platform.OS === "android" ? "always" : undefined}
        sharedCookiesEnabled={false}
        originWhitelist={["http://*", "https://*", "file://*", "data:*", "content:*"]}
        style={{
            flex: 1,
        }}
        scrollEnabled={true}
        source={{ uri: viewUri }}
        bounces={false}
    />;

)