一、在 Firebase創(chuàng)建項(xiàng)目

如下圖，點(diǎn)擊位置，創(chuàng)建一個(gè)項(xiàng)目

二、創(chuàng)建好項(xiàng)目后，新增應(yīng)用程序創(chuàng)建應(yīng)用程序

1.我這里是Android，直接選中創(chuàng)建Android應(yīng)用程序

image.png

2.填寫相關(guān)數(shù)據(jù)

image.png

三、啟用Google登錄

image.png

image.png

三、登錄流程官方文檔

到這里就配置完成了，Android應(yīng)用程序會(huì)生成一個(gè)google-services.json文件
1.導(dǎo)入sdk，查看sdk操作說明就行

image.png

2.登錄代碼片段

/**
     * google登錄
     */
    private fun googleLogin(){
        val googleIdOption = GetGoogleIdOption.Builder()
            .setServerClientId(getString(R.string.default_web_client_id))
            .setFilterByAuthorizedAccounts(true)
            .build()
        val request = GetCredentialRequest.Builder()
            .addCredentialOption(googleIdOption)
            .build()

        lifecycleScope.launch {
            try {
                val result = credentialManager.getCredential(
                    context = this@LoginActivity,
                    request = request
                )
                handleSignIn(result.credential)
            } catch (e: GetCredentialException) {
                LogUtils.e("print", "Couldn't retrieve user's credentials: ${e.localizedMessage}")
            }
        }

    }

default_web_client_id這個(gè)是自動(dòng)生成的

private fun handleSignIn(credential: Credential) {
        if (credential is CustomCredential && credential.type == TYPE_GOOGLE_ID_TOKEN_CREDENTIAL) {
            val googleIdTokenCredential = GoogleIdTokenCredential.createFrom(credential.data)
            firebaseAuthWithGoogle(googleIdTokenCredential.idToken)
        } else {
            LogUtils.w("print", "Credential is not of type Google ID!")
        }
    }


     /**
     * 獲取Google 登錄token
     */
    private fun firebaseAuthWithGoogle(idToken: String) {
        val credential = GoogleAuthProvider.getCredential(idToken, null)
        auth.signInWithCredential(credential)
            .addOnCompleteListener(this) { task ->
                if (task.isSuccessful) {
                    val user = auth.currentUser
                    updateUI(user)
                } else {
                    updateUI(null)
                }
            }
    }

    /**
     * 更新ui
     */
    private fun updateUI(user: FirebaseUser?){
        if (user != null){
            val googleId = user.providerData.find {
                it.providerId == GoogleAuthProvider.PROVIDER_ID
            }?.uid
            otherLogin(googleId,user.email,LoginBean.TYPE_GOOGLE)
        }

    }

最后一步獲取到firebaseUser，也就是用戶數(shù)據(jù)，到這里算是完成了授權(quán)登錄，后面的邏輯就是和自己的登錄流程有關(guān)了

四、遇到的問題

按照官方的代碼可能會(huì)出現(xiàn)以下錯(cuò)誤
Couldn't retrieve user's credentials: During begin sign in, failure response from one tap: 16: [28433] Cannot find a matching credential.

1.可能原因SHA1配置的不正確，或者包名不匹配
2.上面代碼中setFilterByAuthorizedAccounts(true)錯(cuò)誤，設(shè)置了true: 僅允許 用戶在當(dāng)前應(yīng)用的 OAuth 授權(quán)列表中的 Google 賬戶登錄。這里我們應(yīng)該設(shè)置為false