java.lang.IllegalStateException：您必须设置文本或视图

Question

我是 android 新手，在单击处理数据库请求的按钮时不断收到此错误。我不知道发生了什么事，因为昨天一切正常，我根本没有做任何更改。

错误日志：

E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.myapplication, PID: 7510
java.lang.IllegalStateException: You must either set a text or a view
    at com.android.internal.util.Preconditions.checkState(Preconditions.java:173)
    at android.widget.Toast.show(Toast.java:188)
    at com.example.myapplication.LoginActivity$userLogin$stringRequest$3.onErrorResponse(LoginActivity.kt:106)
    at com.android.volley.Request.deliverError(Request.java:617)
    at com.android.volley.ExecutorDelivery$ResponseDeliveryRunnable.run(ExecutorDelivery.java:104)
    at android.os.Handler.handleCallback(Handler.java:938)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:223)
    at android.app.ActivityThread.main(ActivityThread.java:7656)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:592)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:947)

代码错误日志指的是：

private fun userLogin() {
        val email: String = emailText.text.toString().trim()
        val password: String = passwordText.text.toString().trim()

        val stringRequest = object : StringRequest(
                Method.POST, URL_LOGIN,
                Response.Listener<String> { response ->
                    try {
                        val obj = JSONObject(response)
                        if (!obj.getBoolean("error")) {
                            SharedPrefManager.getInstance(applicationContext)
                                    ?.userLogin(
                                            obj.getInt("id"),
                                            obj.getString("email"))
                            Toast.makeText(applicationContext, obj.getString("message"), Toast.LENGTH_LONG).show()

                        }else{
                            Toast.makeText(applicationContext, obj.getString("message"), Toast.LENGTH_LONG).show()

                        }
                    } catch (e: JSONException) {
                        e.printStackTrace()
                    }
                },
                Response.ErrorListener { volleyError -> Toast.makeText(applicationContext, volleyError.message, Toast.LENGTH_LONG).show() }) {
            @Throws(AuthFailureError::class)
            override fun getParams(): Map<String, String> {
                val params = HashMap<String, String>()
                params.put("email", email)
                params.put("password", password)
                return params
            }
        }

调用该函数的代码：

 override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.login_layout)

    buttonLogin.setOnClickListener {
        userLogin()
        this.finish()
    }
}

老实说，我不知道这个错误意味着什么，如果我需要提供更多代码，请告诉我。

Answer 1

在 android 11（API 级别 30）中将在类方法Compatibility.isChangeEnabled(CHANGE_TEXT_TOASTS_IN_THE_SYSTEM)中返回 true ，对于 android 11，如android 开发者网站中提到的Toastshow()

现在，如果您想跳过此异常，请不要 在此处传递nullToast 的消息参数， 在某些情况下您将获得 null，因此您检查 null 然后显示如下Toast.makeText(applicationContext, obj.getString("message"),Toast.LENGTH_LONG).show()obj.getString("message")Toast

if(obj!=null && obj.getString("message")!=null){
Toast.makeText(applicationContext, obj.getString("message"), Toast.LENGTH_LONG).show()
}else//static message

这样我们就可以防止异常

Answer 2

private fun userLogin() {
        val email: String = emailText.text.toString().trim()
        val password: String = passwordText.text.toString().trim()

        val stringRequest = object : StringRequest(
                Method.POST, URL_LOGIN,
                Response.Listener<String> { response ->
                    try {
                        val obj = JSONObject(response)
                        if (!obj.getBoolean("error")) {
                            SharedPrefManager.getInstance(applicationContext)
                                    ?.userLogin(
                                            obj.getInt("id"),
                                            obj.getString("email"))
                            Toast.makeText(applicationContext, obj.getString("message"), Toast.LENGTH_LONG).show()

                        }else{
                            Toast.makeText(applicationContext, obj.getString("message"), Toast.LENGTH_LONG).show()

                        }
                           this.finish()
                    } catch (e: JSONException) {
                        e.printStackTrace()
                    }
                },
                Response.ErrorListener { volleyError -> Toast.makeText(applicationContext, volleyError.message, Toast.LENGTH_LONG).show() }) {
            @Throws(AuthFailureError::class)
            override fun getParams(): Map<String, String> {
                val params = HashMap<String, String>()
                params.put("email", email)
                params.put("password", password)
                return params
            }
        }


override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    setContentView(R.layout.login_layout)

    buttonLogin.setOnClickListener {
        userLogin()
       
    }
}