在Fragment中实现onKeyPreIme(int keyCode,KeyEvent事件)

Question

我想不出如何实现onKeyPreIme(int keyCode, KeyEvent event)的Fragment.

@Override
public boolean onKeyPreIme(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK && 
        event.getAction() == KeyEvent.ACTION_UP) {
            // do your stuff
            return false;
    }
    return super.dispatchKeyEvent(event);
}

我尝试了很多,但没有任何作用.另外,我在Google或Stack Overflow上找不到任何内容.我想在按下后退键并且软键盘启动时执行操作.设置onKeyListener我的EditTexts不起作用,因为KeyEvent.KEYCODE_BACK当软键盘启动时不会调用.我感谢任何帮助和源代码.

Answer 1

这是我的解决方案,它对我来说非常好,但每个人的需求都不同.

首先我将EditText子类化并连接一个监听器(Google应该将其设为默认值)

public class ListenerEditText extends EditText {

    private KeyImeChange keyImeChangeListener;

    public ListenerEditText(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    public void setKeyImeChangeListener(KeyImeChange listener){
        keyImeChangeListener = listener;
    }

    public interface KeyImeChange {
        public void onKeyIme(int keyCode, KeyEvent event);
    }

    @Override
    public boolean onKeyPreIme (int keyCode, KeyEvent event){
        if(keyImeChangeListener != null){
            keyImeChangeListener.onKeyIme(keyCode, event);
        }        
        return false;
    }
}

然后你可以从任何地方附加一个监听器:

myListenerEditText.setKeyImeChangeListener(new KeyImeChange() {

    @Override
    public void onKeyIme(int keyCode, KeyEvent event) {
        // All keypresses with the keyboard open will come through here!
        // You could also bubble up the true/false if you wanted 
        // to disable propagation.
    }
});

Answer 2

我能够通过对与键盘输入相关的EditText视图进行子类化来实现onKeyPreIme.目标是创建一个自定义锁定屏幕,用户必须输入密码或离开应用程序.当用户点击"键盘向下"按钮时,键盘不会消失.

确保为子类EditText创建单独的.java文件.另外,请确保在下面的代码中使用构造函数(必须传递AttrubuteSet).

我意识到我的onKeyPreIme实现可能与你的不匹配,但它确实演示了如何在InputMethodManager之前拦截键盘事件.

我希望这有帮助.

截图UserLockActivity

EditText子类

public class LockEditText extends EditText {
    /* Must use this constructor in order for the layout files to instantiate the class properly */
    public LockEditText(Context context, AttributeSet attrs) 
    {
        super(context, attrs);
        // TODO Auto-generated constructor stub
    }

    @Override
    public boolean onKeyPreIme (int keyCode, KeyEvent event)
    {
        // Return true if I handle the event:
            // In my case i want the keyboard to not be dismissible so i simply return true
            // Other people might want to handle the event differently
        System.out.println("onKeyPreIme " +event);
        return true;
    }

}

UserLockActivity.java

public class UserLockActivity extends Activity 
{
    private LockEditText editText1;
    private LockEditText editText2;
    private LockEditText editText3;
    private LockEditText editText4;
    @Override
    protected void onCreate(Bundle savedInstanceState) 
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_user_lock);
        editText1 = (LockEditText) findViewById(R.id.lock_text_1);
        editText2 = (LockEditText) findViewById(R.id.lock_text_2);
        editText3 = (LockEditText) findViewById(R.id.lock_text_3);
        editText4 = (LockEditText) findViewById(R.id.lock_text_4);
        setupTextChangedListener(editText1);
        setupTextChangedListener(editText2);
        setupTextChangedListener(editText3);
        setupTextChangedListener(editText4);
        // A method to bring out the keyboard when the view appears
        setFocusOnEditText(editText1);
    }

    public void setFocusOnEditText(LockEditText editText)
    {
        editText.clearFocus();
        editText.requestFocus();
        InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);

        imm.toggleSoftInput(InputMethodManager.SHOW_FORCED,0);
    }
    public void setupTextChangedListener(LockEditText editText)
    {
        editText.addTextChangedListener(new TextWatcher() 
        {
            @Override
            public void onTextChanged(CharSequence s, int start, int before, int count) 
            {

            }

            @Override
            public void afterTextChanged(Editable arg0) 
            {
                // TODO Auto-generated method stub
            }

            @Override
            public void beforeTextChanged(CharSequence arg0, int arg1,int arg2, int arg3) 
            {
                // TODO Auto-generated method stub
            }
        });
    }
}

activity_user_lock.xml布局文件

<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"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".UserLockActivity" >

    <TextView
        android:id="@+id/main_lock_text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerHorizontal="true"
        android:layout_alignParentTop="true"
        android:paddingTop="60dp"
        android:paddingBottom="20dp"
        android:text="@string/enter_passcode"
        android:textAppearance="?android:attr/textAppearanceLarge" />

    <LinearLayout
        android:id="@+id/lock_input_layout"
        android:layout_width="match_parent"
        android:layout_height="60dp"
        android:layout_below="@+id/main_lock_text"
        android:orientation="horizontal" >

        <com.yourpackage.yourappname.LockEditText
            android:id="@+id/lock_text_1"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:layout_weight="1"
            android:ems="10"
            android:inputType="numberPassword"
            android:textSize="30sp"
            android:gravity="center_horizontal"
            android:textStyle="bold" >
        </com.yourpackage.yourappname.LockEditText>
        <com.yourpackage.yourappname.LockEditText
            android:id="@+id/lock_text_2"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:layout_weight="1"
            android:ems="10"
            android:inputType="numberPassword"
            android:textSize="30sp"
            android:gravity="center_horizontal"
            android:textStyle="bold" >
        </com.yourpackage.yourappname.LockEditText>
        <com.yourpackage.yourappname.LockEditText
            android:id="@+id/lock_text_3"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:layout_weight="1"
            android:ems="10"
            android:inputType="numberPassword"
            android:textSize="30sp" 
            android:gravity="center_horizontal"
            android:textStyle="bold">
        </com.yourpackage.yourappname.LockEditText>
        <com.yourpackage.yourappname.LockEditText
            android:id="@+id/lock_text_4"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center_horizontal"
            android:layout_weight="1"
            android:ems="10"
            android:inputType="numberPassword"
            android:textSize="30sp"
            android:gravity="center_horizontal"
            android:textStyle="bold" >
        </com.yourpackage.yourappname.LockEditText>
    </LinearLayout>

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/lock_input_layout"
        android:layout_centerHorizontal="true"
        android:text="text" />

</RelativeLayout>