Question

我想实现一个开关按钮android.widget.Switch（可从API v.14获得）。

<Switch
    android:id="@+id/switch1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Switch" />

但我不确定如何为按钮添加事件监听器。它应该是一个“onClick”监听器吗？我怎么知道它是否“开启”了？

Answer 1

Switch继承了CompoundButton的属性，因此我建议使用OnCheckedChangeListener

mySwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
        // do something, the isChecked will be
        // true if the switch is in the On position
    }
});

Answer 2

使用以下代码段通过XML将切换添加到布局：

<Switch
     android:id="@+id/on_off_switch"
     android:layout_width="wrap_content"
     android:layout_height="wrap_content"
     android:textOff="OFF"
     android:textOn="ON"/>

然后在Activity的onCreate方法中，获取对Switch的引用并设置其OnCheckedChangeListener：

Switch onOffSwitch = (Switch)  findViewById(R.id.on_off_switch); 
onOffSwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

@Override
public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
    Log.v("Switch State=", ""+isChecked);
}       

});

Answer 3

定义XML布局：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.neoecosystem.samplex.SwitchActivity">

    <Switch
        android:id="@+id/myswitch"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content" />

</RelativeLayout>

然后创建一个活动

public class SwitchActivity extends ActionBarActivity implements CompoundButton.OnCheckedChangeListener {

    Switch mySwitch = null;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_switch);


        mySwitch = (Switch) findViewById(R.id.myswitch);
        mySwitch.setOnCheckedChangeListener(this);
    }

    @Override
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
        if (isChecked) {
            // do something when check is selected
        } else {
            //do something when unchecked
        }
    }

    ****
}

========对于以下API 14 ，请使用SwitchCompat =========

XML

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.neoecosystem.samplex.SwitchActivity">

    <android.support.v7.widget.SwitchCompat
        android:id="@+id/myswitch"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content" />

</RelativeLayout>

活动

public class SwitchActivity extends ActionBarActivity implements CompoundButton.OnCheckedChangeListener {

    SwitchCompat mySwitch = null;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_switch);


        mySwitch = (SwitchCompat) findViewById(R.id.myswitch);
        mySwitch.setOnCheckedChangeListener(this);
    }

    @Override
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
        if (isChecked) {
            // do something when checked is selected
        } else {
            //do something when unchecked
        }
    }
   *****
}

Answer 4

对于那些使用Kotlin的人，您可以为开关设置一个监听器（在这种情况下具有ID mySwitch），如下所示：

mySwitch.setOnCheckedChangeListener { _, isChecked -> run {
        // do whatever you need to do when the switch is toggled here
    }
}

如果当前检查（ON）开关，则

isChecked为真，否则为假。

Answer 5

Switch小部件的布局是这样的。

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">
    <Switch
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginRight="20dp"
        android:gravity="right"
        android:text="All"
        android:textStyle="bold"
        android:textColor="@color/black"
        android:textSize="20dp"
        android:id="@+id/list_toggle" />
</LinearLayout>

在Activity类中，您可以通过两种方式进行编码。取决于您可以使用的代码。

第一种方式

public class ActivityClass extends Activity implements CompoundButton.OnCheckedChangeListener {
Switch list_toggle;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.return_vehicle);

    list_toggle=(Switch)findViewById(R.id.list_toggle);
    list_toggle.setOnCheckedChangeListener(this);
    }
}

public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
    if(isChecked) {
        list_toggle.setText("Only Today's");  //To change the text near to switch
        Log.d("You are :", "Checked");
    }
    else {
        list_toggle.setText("All List");   //To change the text near to switch
        Log.d("You are :", " Not Checked");
    }
}

第二种方式

public class ActivityClass extends Activity {
Switch list_toggle;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.return_vehicle);

    list_toggle=(Switch)findViewById(R.id.list_toggle);
    list_toggle.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
       @Override
       public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
          if(isChecked) {
             list_toggle.setText("Only Today's");  //To change the text near to switch
             Log.d("You are :", "Checked");
          }
          else {
             list_toggle.setText("All List");  //To change the text near to switch
             Log.d("You are :", " Not Checked");
          }
       }       
     });
   }
}

Answer 6

有两种方法，

使用xml onclick视图如下所示以XML添加Switch：

<Switch
android:id="@+id/switch1"
android:onClick="toggle"/>

在YourActivity类中（例如对于MainActivity.java）

    Switch toggle; //outside oncreate
    toggle =(Switch) findViewById(R.id.switch1); // inside oncreate

    public void toggle(View view) //outside oncreate
    {
        if( toggle.isChecked() ){
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                start.setBackgroundColor(getColor(R.color.gold));
                stop.setBackgroundColor(getColor(R.color.white));
            }
        }
        else
        {
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                stop.setBackgroundColor(getColor(R.color.gold));
                start.setBackgroundColor(getColor(R.color.white));
            }
        }
    }

使用点击监听器

添加XML开关，如下所示：

在YourActivity类中（例如对于MainActivity.java）

    Switch toggle; // outside oncreate
    toggle =(Switch) findViewById(R.id.switch1);  // inside oncreate


    toggle.setOnClickListener(new View.OnClickListener() {   // inside oncreate
        @Override
        public void onClick(View view) {

            if( toggle.isChecked() ){
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                    start.setBackgroundColor(getColor(R.color.gold));
                }
            }
            else
            {
                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
                    stop.setBackgroundColor(getColor(R.color.gold));
                }
            }

        }

    });

Answer 7

2020年9月-以编程方式回答

您可以通过编程的方式为Switch Widget和Material Design做到这一点：

Switch yourSwitchButton = findViewById(R.id.switch_id);

yourSwitchButton.setChecked(true); // true is open, false is close.

yourSwitchButton.setOnCheckedChangeListener((compoundButton, b) -> {
        if (b){
          //open job.
        }  
        else  {
          //close job.
        }
    });

@canerkaseler

Answer 8

您可以将DataBinding和ViewModel用于Switch Checked Change事件

<layout 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">

    <data>

        <variable
                name="viewModel"
                type="com.example.ui.ViewModel" />
    </data>
    <Switch
            android:id="@+id/on_off_switch"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:onCheckedChanged="@{(button, on) -> viewModel.onCheckedChange(on)}"
     />

Answer 9

我的解决方案，使用SwitchCompat和Kotlin。在我的情况下，仅当用户通过UI触发更改时，我才需要对更改做出反应。实际上，我的开关对LiveData有反应，这使得setOnClickListener和setOnCheckedChangeListener都无法使用。 setOnClickListener实际上对用户交互做出正确反应，但是如果用户在开关上拖动拇指则不会触发。如果以编程方式（例如，由观察者）切换了开关，则另一端的setOnCheckedChangeListener也将被触发。现在，在我的情况下，该开关位于两个片段上，因此在某些情况下，onRestoreInstanceState会触发带有旧值的开关覆盖正确的值。

因此，我查看了SwitchCompat的代码，并成功地模仿了它在区分单击和拖动方面的行为，并使用它来构建了一个可以正常工作的自定义触摸侦听器。我们开始：

/**
 * This function calls the lambda function passed with the right value of isChecked
 * when the switch is tapped with single click isChecked is relative to the current position so we pass !isChecked
 * when the switch is dragged instead, the position of the thumb centre where the user leaves the
 * thumb is compared to the middle of the switch, and we assume that left means false, right means true
 * (there is no rtl or vertical switch management)
 * The behaviour is extrapolated from the SwitchCompat source code
 */
class SwitchCompatTouchListener(private val v: SwitchCompat, private val lambda: (Boolean)->Unit) :  View.OnTouchListener {
    companion object {
        private const val TOUCH_MODE_IDLE = 0
        private const val TOUCH_MODE_DOWN = 1
        private const val TOUCH_MODE_DRAGGING = 2
    }

    private val vc = ViewConfiguration.get(v.context)
    private val mScaledTouchSlop = vc.scaledTouchSlop
    private var mTouchMode = 0
    private var mTouchX = 0f
    private var mTouchY = 0f

    /**
     * @return true if (x, y) is within the target area of the switch thumb
     * x,y and rect are in view coordinates, 0,0 is top left of the view
     */
    private fun hitThumb(x: Float, y: Float): Boolean {
        val rect = v.thumbDrawable.bounds
        return x >= rect.left && x <= rect.right && y >= rect.top && y <= rect.bottom
    }

    override fun onTouch(view: View, event: MotionEvent): Boolean {
        if (view == v) {
            when (MotionEventCompat.getActionMasked(event)) {
                MotionEvent.ACTION_DOWN -> {
                    val x = event.x
                    val y = event.y
                    if (v.isEnabled && hitThumb(x, y)) {
                        mTouchMode = TOUCH_MODE_DOWN;
                        mTouchX = x;
                        mTouchY = y;
                    }
                }
                MotionEvent.ACTION_MOVE -> {
                    val x = event.x
                    val y = event.y
                    if (mTouchMode == TOUCH_MODE_DOWN &&
                        (abs(x - mTouchX) > mScaledTouchSlop || abs(y - mTouchY) > mScaledTouchSlop)
                    )
                        mTouchMode = TOUCH_MODE_DRAGGING;
                }
                MotionEvent.ACTION_UP,
                MotionEvent.ACTION_CANCEL -> {
                    if (mTouchMode == TOUCH_MODE_DRAGGING) {
                        val r = v.thumbDrawable.bounds
                        if (r.left + r.right < v.width) lambda(false)
                        else lambda(true)
                    } else lambda(!v.isChecked)
                    mTouchMode = TOUCH_MODE_IDLE;
                }
            }
        }
        return v.onTouchEvent(event)
    }
}

如何使用它：

实际的监听器接受带有代码的lambda来执行：

myswitch.setOnTouchListener(
    SwitchCompatTouchListener(myswitch) {
        // here goes all the code for your callback, in my case
        // i called a service which, when successful, in turn would 
        // update my liveData 
        viewModel.sendCommandToMyService(it) 
    }
)

为了完整起见，状态switchstate（如果有）的观察者是这样的：

switchstate.observe(this, Observer {
    myswitch.isChecked = it
})

Answer 10

在科特林：

        switch_button.setOnCheckedChangeListener { buttonView, isChecked ->
        if (isChecked) {
            // The switch enabled
            text_view.text = "Switch on"

        } else {
            // The switch disabled
            text_view.text = "Switch off"

        }
    }

Answer 11

在“活动”类中

 switch.setOnCheckedChangeListener((CompoundButton.OnCheckedChangeListener) (buttonView, isChecked) -> {
                if (isChecked){
                    // your code
                } else {
                    // your code
                }
            });

Switch小部件的布局

   <androidx.appcompat.widget.SwitchCompat
                android:id="@+id/switch"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="center"
                android:checked="true"
                android:layoutDirection="ltr"/>

android.widget.Switch - 开/关事件监听器？

11 个答案: