如何在 Android 上将图像字符串转换为整数？

Question

我想从 Firebase 检索图像并将其放置在 canvas 中，以便我使用它放置在自定义 google 标记中。使用 .toInt() 方法时出现错误。也许这是一种错误的做法。

代码：

var loggedInUser : User = User()

                            mFireStore.collection(Constants.USERS)
                                    .document(FirestoreClass().getCurrentUserId())
                                    .get()
                                    .addOnSuccessListener { document ->
                                        loggedInUser = document.toObject(User::class.java)!!
                                    }
                            canvas1.drawBitmap(BitmapFactory.decodeResource(resources,loggedInUser.image.toInt()), 0F, 0F, color)
                            canvas1.drawText("User Name!", 30F, 40F, color)




                            // add marker to Map

                            // add marker to Map
                            markerOptions
                                    .position(LatLng(mLastLocation!!.latitude, mLastLocation!!.longitude))
                                    .title("Current Location")
                                    /*.snippet(address)*/
                                    .icon(BitmapDescriptorFactory.fromBitmap(bmp))

                            mCurrentMarker = googleMap.addMarker(markerOptions)

我得到错误的logcat：

2021-07-06 19:33:54.839 10676-10676/com.example.aroundyouapp E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.aroundyouapp, PID: 10676
java.lang.NumberFormatException: For input string: ""
    at java.lang.Integer.parseInt(Integer.java:627)
    at java.lang.Integer.parseInt(Integer.java:650)
    at com.example.aroundyouapp.activities.MainActivity$getCurrentLocation.onLocationResult(MainActivity.kt:394)
    at com.google.android.gms.internal.location.zzau.notifyListener(Unknown Source:4)
    at com.google.android.gms.common.api.internal.ListenerHolder.notifyListenerInternal(com.google.android.gms:play-services-base@@17.1.0:17)
    at com.google.android.gms.common.api.internal.ListenerHolder$zaa.handleMessage(com.google.android.gms:play-services-base@@17.1.0:6)
    at android.os.Handler.dispatchMessage(Handler.java:107)
    at com.google.android.gms.internal.base.zar.dispatchMessage(com.google.android.gms:play-services-base@@17.1.0:8)
    at android.os.Looper.loop(Looper.java:214)
    at android.app.ActivityThread.main(ActivityThread.java:7356)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

如何将字符串格式的图像（即 loggedInUser.image）转换为 Int，以便将图像放置在 canvas ？也许这是一个愚蠢的问题，但我是新手所以是的。

提前致谢

编辑 1：

我用来在导航菜单中显示用户头像的代码：

fun loadUserData(activity: Activity){
    //This function is called in MainActivity in the onCreate method.
    mFireStore.collection(Constants.USERS)
        .document(getCurrentUserId())
        .get()
        .addOnSuccessListener { document ->
            val loggedInUser = document.toObject(User::class.java)

            when(activity){
                is MyProfileActivity -> {
                    activity.setUserDataInUI(loggedInUser!!)
                }
                is MainActivity -> {
                    activity.updateNavigationUserDetails(loggedInUser!!)
                }
            }
        }
}

fun updateNavigationUserDetails(user: User){
    hideProgressDialog()
    mUserName = user.name
    Glide
            .with(this)
            .load(user.image)
            .centerCrop()
            .placeholder(R.drawable.ic_user_place_holder)
            .into(nav_user_image)

    tv_username.text = user.name
}

编辑 2：

我尝试了 Ragu 的回答。应用程序在尝试后崩溃了。

这是 logcat 中的错误。

2021-07-14 19:07:04.779 18663-18663/com.example.aroundyouapp E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.aroundyouapp, PID: 18663
java.lang.NumberFormatException: For input string: "https://firebasestorage.googleapis.com/v0/b/aroundyou-5f1d2.appspot.com/o/USER_IMAGE1624282533208.jpg?alt=media&token=731ea81d-32a0-4378-aa7b-0d7764260e41"
    at java.lang.Integer.parseInt(Integer.java:615)
    at java.lang.Integer.parseInt(Integer.java:650)
    at com.example.aroundyouapp.activities.MainActivity$getCurrentLocation$onLocationResult.onSuccess(MainActivity.kt:374)
    at com.example.aroundyouapp.activities.MainActivity$getCurrentLocation$onLocationResult.onSuccess(MainActivity.kt:349)
    at com.google.android.gms.tasks.zzn.run(Unknown Source:4)
    at android.os.Handler.handleCallback(Handler.java:883)
    at android.os.Handler.dispatchMessage(Handler.java:100)
    at android.os.Looper.loop(Looper.java:214)
    at android.app.ActivityThread.main(ActivityThread.java:7356)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

我上次遇到了同样的错误，但这次 link 图像显示在 logcat

编辑 3

尝试更新 Ragu 的答案 2 后出现此错误

2021-07-14 20:05:57.399 20234-20234/com.example.aroundyouapp E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.aroundyouapp, PID: 20234
android.os.NetworkOnMainThreadException
    at android.os.StrictMode$AndroidBlockGuardPolicy.onNetwork(StrictMode.java:1565)
    at java.net.Inet6AddressImpl.lookupHostByName(Inet6AddressImpl.java:115)
    at java.net.Inet6AddressImpl.lookupAllHostAddr(Inet6AddressImpl.java:103)
    at java.net.InetAddress.getAllByName(InetAddress.java:1152)
    at com.android.okhttp.Dns.lookup(Dns.java:41)
    at com.android.okhttp.internal.http.RouteSelector.resetNextInetSocketAddress(RouteSelector.java:178)
    at com.android.okhttp.internal.http.RouteSelector.nextProxy(RouteSelector.java:144)
    at com.android.okhttp.internal.http.RouteSelector.next(RouteSelector.java:86)
    at com.android.okhttp.internal.http.StreamAllocation.findConnection(StreamAllocation.java:176)
    at com.android.okhttp.internal.http.StreamAllocation.findHealthyConnection(StreamAllocation.java:128)
    at com.android.okhttp.internal.http.StreamAllocation.newStream(StreamAllocation.java:97)
    at com.android.okhttp.internal.http.HttpEngine.connect(HttpEngine.java:289)
    at com.android.okhttp.internal.http.HttpEngine.sendRequest(HttpEngine.java:232)
    at com.android.okhttp.internal.huc.HttpURLConnectionImpl.execute(HttpURLConnectionImpl.java:465)
    at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getResponse(HttpURLConnectionImpl.java:411)
    at com.android.okhttp.internal.huc.HttpURLConnectionImpl.getInputStream(HttpURLConnectionImpl.java:248)
    at com.android.okhttp.internal.huc.DelegatingHttpsURLConnection.getInputStream(DelegatingHttpsURLConnection.java:211)
    at com.android.okhttp.internal.huc.HttpsURLConnectionImpl.getInputStream(HttpsURLConnectionImpl.java:30)
    at com.example.aroundyouapp.activities.MainActivity$getCurrentLocation$onLocationResult.onSuccess(MainActivity.kt:379)
    at com.example.aroundyouapp.activities.MainActivity$getCurrentLocation$onLocationResult.onSuccess(MainActivity.kt:352)
    at com.google.android.gms.tasks.zzn.run(Unknown Source:4)
    at android.os.Handler.handleCallback(Handler.java:883)
    at android.os.Handler.dispatchMessage(Handler.java:100)
    at android.os.Looper.loop(Looper.java:214)
    at android.app.ActivityThread.main(ActivityThread.java:7356)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

Answer 1

假设您正在尝试显示 Base64 格式的图像。

将传入的Base64字符串解码为ByteArray

val imageByteArray = Base64.decode(user.image, Base64.DEFAULT)

然后加载 imageByteArray 到 Glide 如下。

Glide
   .with(this)
   .asBitmap()
   .load(imageByteArray)  // ==> Pass the ByteArray here  
   .into(nav_user_image)

编辑 1：更新答案

从您的代码中我可以看出，绘制到 canvas 的代码位于 snapshots 的 addOnSuccessListener 之外。但是您在分配数据的 addOnSuccessListener 完成之前访问 loggedInUser 的字段。

addOnSuccessListener is async operation and will not be executed in sequence like you written in your existing code.

将下面的代码移到addOnSuccessListener.

canvas1.drawBitmap(BitmapFactory.decodeResource(resources,loggedInUser.image.toInt()), 0F, 0F, color)
canvas1.drawText("User Name!", 30F, 40F, color)

您现有的代码。

 mFireStore.collection(Constants.USERS)
                                    .document(FirestoreClass().getCurrentUserId())
                                    .get()
                                    .addOnSuccessListener { document ->
                                        loggedInUser = document.toObject(User::class.java)!!
                                    }
                            canvas1.drawBitmap(BitmapFactory.decodeResource(resources,loggedInUser.image.toInt()), 0F, 0F, color)
                            canvas1.drawText("User Name!", 30F, 40F, color)

更新答案 2：

根据错误日志，图像被检索为远程 url，可以直接加载到 ImageView。但是当你试图在 canvas 中绘制它时，你需要将来自远程 url 的文件解码为 stream，然后将其设置在 Canvas.

类似下面的内容

URL url = new URL(<PASS YOUR URL from FIREBASE>);
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
 ....
Bitmap receivedImageasBitmap = BitmapFactory.decodeStream(connection .getInputStream());
.. 
canvas1.drawBitmap(receivedImageasBitmap)

如何在 Android 上将图像字符串转换为整数？

How to convert an image string into integer on Android?

google-maps-markers

android-canvas

kotlin

firebase

android-bitmap