在clojurescript re-natal中使用RNCamera捕获图片时出错
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【中文标题】在clojurescript re-natal中使用RNCamera捕获图片时出错【英文标题】:Error capturing picture with RNCamera in clojurescript re-natal 【发布时间】:2020-03-10 21:39:23 【问题描述】:我正在尝试编写以下js代码,用于在re-natal中使用react-native-camera拍照:
<RNCamera
ref=ref =>
this.camera = ref;
style=styles.preview
type=RNCamera.Constants.Type.back
flashMode=RNCamera.Constants.FlashMode.on
/>
<View style= flex: 0, flexDirection: 'row', justifyContent: 'center' >
<TouchableOpacity onPress=this.takePicture.bind(this) style=styles.capture>
<Text style= fontSize: 14 > SNAP </Text>
</TouchableOpacity>
</View>
takePicture = async() =>
if (this.camera)
const options = quality: 0.5, base64: true ;
const data = await this.camera.takePictureAsync(options);
console.log(data.uri);
;
我有以下 clojurescript 代码:
(defn take-picture [camera]
(go (let [picture (<! (.takePictureAsync camera :quality 0.5 :base-64 true))]
(prn "uri is " (.-uri picture))
)))
(defn camera- []
(fn []
[safe-area-view
[camera
:ref (fn [cam] (this-as this (set! (.-Camera this) cam)))
:style :width 500 :height 500 :justify-content "flex-end" :align-items "center" :border-color "black" :min-height "10%"
:type (-> ReactNativeCamera .-RNCamera .-Constants .-Type .-back)
]
[view :style :justify-content "center"
[touchable-opacity :on-press take-picture
:style :margin 5 :background-color "#999" :padding 10 :border-radius 5
[text "Take Pic"]
]]
]))
但是在点击触发拍照功能的可触摸不透明度时,我收到以下错误:camera.takePictureAsync is not a function
我做错了什么?
【问题讨论】:
如果 console.log 是相机变量,你会得到什么?这可以给你提示 (prn camera) 给出#object[Class [object Object]],但是当我这样做时(js/console.log camera),应用程序冻结。 嗯......这肯定是 clojure :( 我看到可疑的是你从哪里得到那个相机对象 :| 也许 :on-press 应该有一个调用拍照和传递的内联函数ref 对象,你应该看看你是如何传递那个 ref 【参考方案1】:需要确保 @camera-ref 已创建,然后将其传递给函数,如下例所示:
(let [camera-ref (atom nil)]
[camera :ref #(reset! camera-ref %)]
......
:on-press (fn []
(let [camera @camera-ref]
(-> (.takePictureAsync camera)
(.then #(prn "image-captured: " %))
(.catch #(prn "Error capturing image: " %))))))
【讨论】:
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