未找到Android活动异常（找不到处理Intent的活动） _android

家资是何物，积帙列梁梠。这篇文章主要讲述未找到Android活动异常：找不到处理Intent的活动相关的知识，希望能为你提供帮助。
这似乎应该很容易修复，有几个帖子带有不同示例的示例代码，更复杂。然而，没有人为这个简单的计划工作过。
BMI计算器有两个活动，MainActivity和BMIResultsScreen。用户在MainActivity中输入他们的体重和身高，并在BMIResultsScreen中查看结果。然后，他们可以选择单击按钮退出，或单击按钮返回MainActivity。退出按钮有效，但返回MainActivity的按钮不起作用。
【未找到Android活动异常（找不到处理Intent的活动）】清单：

< ?xml version="1.0" encoding="utf-8"?> < manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.example.username.bmicalculator"> < application android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/AppTheme"> < activity android:name=".MainActivity"> < intent-filter> < action android:name="android.intent.action.MAIN" /> < category android:name="android.intent.category.LAUNCHER" /> < /intent-filter> < /activity> < activity android:name=".BMIResultsScreen"> < intent-filter> < action android:name="com.example.username.BMIResultsScreen" /> < category android:name="android.intent.category.DEFAULT" /> < /intent-filter> < /activity> < /application>

MainActivity：

package com.example.username.bmicalculatorimport android.content.Intent import android.support.v7.app.AppCompatActivity import android.os.Bundle import kotlinx.android.synthetic.main.activity_main.*class MainActivity : AppCompatActivity() {override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main)setOnClickListenerForButton() }fun calculateBMI(): Double { var weight: Double = (numWeight.getText().toString().toDouble()) var height: Double = (numHeight.getText().toString().toDouble()) var calculatedBMI = (((weight / height) / height)) return calculatedBMI }fun setOnClickListenerForButton() { btnCalculateBMI.setOnClickListener {val intent = Intent("com.example.username.BMIResultsScreen") intent.putExtra("BMIResult", calculateBMI()) startActivity(intent) } } }

第二项活动，BMIResultScreen：

package com.example.username.bmicalculatorimport android.support.v7.app.AppCompatActivity import android.os.Bundle import android.content.Intent import kotlinx.android.synthetic.main.activity_bmiresults_screen.* import java.text.DecimalFormatclass BMIResultsScreen : AppCompatActivity() {override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_bmiresults_screen)showBMIResult() findBMICategory() setExitListener() setCheckAgainListener() }fun showBMIResult(){ var decFormat = DecimalFormat("#.#") var formattedBMI = decFormat.format(getIntent().getExtras().getDouble("BMIResult")) lblBMIResult.setText(formattedBMI.toString()) }fun findBMICategory() { var categoryOfBMI = "Unknown" var resultBMI = getIntent().getExtras().getDouble("BMIResult") if (resultBMI < 15) { categoryOfBMI = "Very Severely Underweight" } else if (resultBMI in 15..16) { categoryOfBMI = "Severely Underweight" } else if (resultBMI > 16 & & resultBMI < = 18.5) { categoryOfBMI = "Underweight" } else if (resultBMI > 18.5 & & resultBMI < = 25) { categoryOfBMI = "Normal (Healthy Weight)" } else if (resultBMI in 25..30) { categoryOfBMI = "Overweight" } else if (resultBMI in 30..35) { categoryOfBMI = "Moderately Obese" } else if (resultBMI in 35..40) { categoryOfBMI = "Severely Obese" } else if (resultBMI > = 40) { categoryOfBMI = "Very Severely Obese" } lblBMIResultCategory.setText(categoryOfBMI) }fun setExitListener() { btnExit.setOnClickListener { this.finishAffinity() } }fun setCheckAgainListener() { btnCheckAgain.setOnClickListener { val intent = Intent("com.example.username.bmicalculator.MainActivity") startActivity(intent) } } }

答案尝试在侦听器中调用onBackPressed()以返回返回Main活动的按钮。