检测对Button的双击,即每当用户双击任何Button时,如何检测到它,并根据Button可以添加与之对应的响应。此处显示了一个示例,其中检测到按钮上的双击,并以吐司的形式添加了与之对应的响应。
第1步:在Android Studio中创建一个空活动。要创建一个项目,请遵循本文-如何在Android Studio中创建/启动新项目? 。检查所选的主要语言是否为Kotlin。
步骤2:在activity_main.xml中,添加一个将检测双击的按钮。
XML
Kotlin
package org.geeksforgeeks.doubletap_onbutton
import android.os.Bundle
import android.view.View
import android.widget.TextView
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
// Declare the button from the layout file as Text View
// Since the method works only on Views
val dBtn = findViewById(R.id.btn)
// Implementing a DoubleClickListener on the Button
dBtn.setOnClickListener(object : DoubleClickListener() {
override fun onDoubleClick(v: View?) {
Toast.makeText(applicationContext,"Double Click",Toast.LENGTH_SHORT).show()
}
})
}
// This class has methods that check if two clicks were registered
// within a span of DOUBLE_CLICK_TIME_DELTA i.e., in our case
// equivalent to 300 ms
abstract class DoubleClickListener : View.OnClickListener {
var lastClickTime: Long = 0
override fun onClick(v: View?) {
val clickTime = System.currentTimeMillis()
if (clickTime - lastClickTime < DOUBLE_CLICK_TIME_DELTA) {
onDoubleClick(v)
}
lastClickTime = clickTime
}
abstract fun onDoubleClick(v: View?)
companion object {
private const val DOUBLE_CLICK_TIME_DELTA: Long = 300 //milliseconds
}
}
}
步骤3:在此步骤中,为双击添加抽象类,并设置将使用抽象类的onClickListener。并表演烤面包。下面是MainActivity.kt类的代码。
科特林
package org.geeksforgeeks.doubletap_onbutton
import android.os.Bundle
import android.view.View
import android.widget.TextView
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
// Declare the button from the layout file as Text View
// Since the method works only on Views
val dBtn = findViewById(R.id.btn)
// Implementing a DoubleClickListener on the Button
dBtn.setOnClickListener(object : DoubleClickListener() {
override fun onDoubleClick(v: View?) {
Toast.makeText(applicationContext,"Double Click",Toast.LENGTH_SHORT).show()
}
})
}
// This class has methods that check if two clicks were registered
// within a span of DOUBLE_CLICK_TIME_DELTA i.e., in our case
// equivalent to 300 ms
abstract class DoubleClickListener : View.OnClickListener {
var lastClickTime: Long = 0
override fun onClick(v: View?) {
val clickTime = System.currentTimeMillis()
if (clickTime - lastClickTime < DOUBLE_CLICK_TIME_DELTA) {
onDoubleClick(v)
}
lastClickTime = clickTime
}
abstract fun onDoubleClick(v: View?)
companion object {
private const val DOUBLE_CLICK_TIME_DELTA: Long = 300 //milliseconds
}
}
}
在仿真器上的输出:
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