button.setOnLongClickListener()函数不起作用。

huangapple
go评论65阅读模式
英文:

button.setOnLongClickListener() function is not working

问题

Sure, here's the translated code portion:

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        btntoste.setOnClickListener {
            Toast.makeText(this, "this is default toast", Toast.LENGTH_SHORT).show()
        }
        btntoste.setOnLongClickListener {
            Toast(this).apply {
                duration = Toast.LENGTH_LONG
                view = layoutInflater.inflate(R.layout.custom_toast, layconstrain)
                show()
            }
            true
        }
    }
}

Please note that I've translated the code as requested, but there might still be issues in your code related to the btntoste and layconstrain elements, which could lead to runtime errors. Make sure those elements are correctly defined in your XML layout file and initialized in your code.

英文:

I want to show a default toast if a button is clicked once and a custom toast if the button is long-clicked. The default toast works but the custom toast doesn't:

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        btntoste.setOnClickListener {
            Toast.makeText(this,"this is defult toaste",Toast.LENGTH_SHORT)
        }
        btntoste.setOnLongClickListener {
            Toast(this).apply {
                duration = Toast.LENGTH_LONG
                view = layoutInflater.inflate(R.layout.custom_toaste, layconstrain)
                show()
            }
        }
    }
}

The logcat error:

failed to add asset path /data/app/com.sumita.toaste-wg1Yd4-KC7e1sn36eDPchA==/base.apk
2023-05-10 11:58:44.858 18737-18737 ResourcesManager        pid-18737                            E  failed to add asset path /data/app/com.sumita.toaste-wg1Yd4-KC7e1sn36eDPchA==/base.apk
2023-05-10 11:58:44.861 18737-18737 ResourcesManager        pid-18737                            E  failed to add asset path /data/app/com.sumita.toaste-wg1Yd4-KC7e1sn36eDPchA==/base.apk
2023-05-10 11:58:45.088  2461-2501  ActivityThread          com.sumita.toaste                    E  Failed to find provider info for cn.teddymobile.free.anteater.den.provider
2023-05-10 11:58:45.229  2461-2461  AndroidRuntime          com.sumita.toaste                    E  FATAL EXCEPTION: main
                                                                                                    Process: com.sumita.toaste, PID: 2461
                                                                                                    java.lang.RuntimeException: Unable to start activity ComponentInfo{com.sumita.toaste/com.sumita.toaste.MainActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
                                                                                                    	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2994)
                                                                                                    	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3072)
                                                                                                    	at android.app.ActivityThread.-wrap11(Unknown Source:0)
                                                                                                    	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1766)
                                                                                                    	at android.os.Handler.dispatchMessage(Handler.java:106)
                                                                                                    	at android.os.Looper.loop(Looper.java:214)
                                                                                                    	at android.app.ActivityThread.main(ActivityThread.java:6977)
                                                                                                    	at java.lang.reflect.Method.invoke(Native Method)
                                                                                                    	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:528)
                                                                                                    	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:910)
                                                                                                    Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.Button.setOnClickListener(android.view.View$OnClickListener)' on a null object reference
                                                                                                    	at com.sumita.toaste.MainActivity.onCreate(MainActivity.kt:17)
                                                                                                    	at android.app.Activity.performCreate(Activity.java:7227)
                                                                                                    	at android.app.Activity.performCreate(Activity.java:7218)
                                                                                                    	at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1214)
                                                                                                    	at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2947)
                                                                                                    	at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3072) 
                                                                                                    	at android.app.ActivityThread.-wrap11(Unknown Source:0) 
                                                                                                    	at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1766) 
                                                                                                    	at android.os.Handler.dispatchMessage(Handler.java:106) 
                                                                                                    	at android.os.Looper.loop(Looper.java:214) 
                                                                                                    	at android.app.ActivityThread.main(ActivityThread.java:6977) 
                                                                                                    	at java.lang.reflect.Method.invoke(Native Method) 
                                                                                                    	at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:528) 
                                                                                                    	at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:910) 

activity_main.xml:

<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <Button
        android:id="@+id/btntoste"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Show Toste"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintHorizontal_bias="0.498"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.266"
        android:backgroundTint="@color/material_dynamic_neutral50"
        android:textColor="@color/white"/>
</androidx.constraintlayout.widget.ConstraintLayout>

Custom toast layout:

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:id="@+id/layconstrain"
    android:padding="16dp"
    android:background="@color/material_dynamic_neutral70">

    <ImageView
        android:id="@+id/imageView"
        android:layout_width="100dp"
        android:layout_height="100dp"
        android:src="@drawable/ic_baseline_circle_notifications_24"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

    <TextView
        android:id="@+id/txtcucont"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="16dp"
        android:text="Hay this is custom toaste"
        android:textSize="15sp"
        android:textColor="@color/purple_700"
        app:layout_constraintBottom_toBottomOf="@+id/imageView"
        app:layout_constraintStart_toEndOf="@+id/imageView"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintVertical_bias="0.583" />
</androidx.constraintlayout.widget.ConstraintLayout>

答案1

得分: 1

需要在 setOnLongClickListener 方法中返回布尔值。我正在使用 viewBinding 来获取视图。尝试这样做

   import android.os.Bundle
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import com.umesh.testapp.databinding.ActivityMainBinding
import com.umesh.testapp.databinding.CustomToasteBinding


class MainActivity : AppCompatActivity() {
    lateinit var binding: ActivityMainBinding
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)
        binding.btntoste.setOnClickListener {
            Toast.makeText(this, "这是默认吐司", Toast.LENGTH_SHORT)
        }
        
        binding.btntoste.setOnLongClickListener {
            val customToasteBinding = CustomToasteBinding.inflate(layoutInflater)
            Toast(applicationContext).apply {
                duration = Toast.LENGTH_LONG
                view = customToasteBinding.root
                show()
            }
            return@setOnLongClickListener true
        }
    }
}
英文:

You need to return boolean value in setOnLongClickListener method like that. I am using viewBinding to fetch view. Try this

import android.os.Bundle
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import com.umesh.testapp.databinding.ActivityMainBinding
import com.umesh.testapp.databinding.CustomToasteBinding


class MainActivity : AppCompatActivity() {
 lateinit var binding: ActivityMainBinding
 override fun onCreate(savedInstanceState: Bundle?) {
     super.onCreate(savedInstanceState)
     binding = ActivityMainBinding.inflate(layoutInflater)
     setContentView(binding.root)
     binding.btntoste.setOnClickListener {
         Toast.makeText(this,"this is defult toaste",Toast.LENGTH_SHORT)
     }
     
     binding.btntoste.setOnLongClickListener {
         val customToasteBinding = CustomToasteBinding.inflate(layoutInflater)
         Toast(applicationContext).apply {
             duration = Toast.LENGTH_LONG
             view = customToasteBinding.root
             show()
         }
         return@setOnLongClickListener true
     }
 }
}

答案2

得分: 0

根据错误信息，btntoste 变量具有 null 值。这是因为您尚未为 btntoste 变量分配值。要解决这个问题：

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        // 通过其id访问按钮
        val toastBtn = findViewById<Button>(R.id.btntoste)

        // 显示默认提示
        toastBtn.setOnClickListener {
            Toast.makeText(this, "这是默认提示", Toast.LENGTH_SHORT).show()
        }

        // 显示自定义提示
        toastBtn.setOnLongClickListener {
            Toast(this).apply {
                duration = Toast.LENGTH_LONG
                view = layoutInflater.inflate(R.layout.custom_toaste, layconstrain)
                show()
            }

            return@setOnLongClickListener true
        }
    }
}

当使用 setOnLongClickListener() 函数时，您还需要返回一个布尔值。

英文:

According to the error, the btntoste variable has a null value. That's because you haven't assigned the btntoste variable. To solve that:

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        //Access the Button using its id
        val toastBtn = findViewById&lt;Button&gt;(R.id.btntoste)
 
        //Display default toast
        toastBtn.setOnClickListener {
            Toast.makeText(this,&quot;this is defult toaste&quot;,Toast.LENGTH_SHORT)
        }

        //Display custom toast
        toastBtn.setOnLongClickListener {
            Toast(this).apply {
                duration = Toast.LENGTH_LONG
                view = layoutInflater.inflate(R.layout.custom_toaste, layconstrain)
                show()
            }

            return@setOnLongClickListener true
        }
    }
}

You also need to return a boolean value when using the setOnLongClickListener() function.

huangapple
  • 本文由 发表于 2023年5月10日 14:31:00
  • 转载请务必保留本文链接：https://go.coder-hub.com/76215481.html
  • android
  • kotlin
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