09 常见事件响应

Posted 2020-09-28

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常见的事件：

1、单击事件onClickListener：略

---

 

2、长按事件onLongClickListener

ThreeAndroidActivity.java:

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button button1 =(Button)findViewById(R.id.button1);
        button1.setOnLongClickListener(new OnLongClickListener(){
			public boolean onLongClick(View v) {
				Log.i("myinfo", "button长按事件。。。");
				return false;
			}
        });
}

运行结果：

验证true和false：

当返回值为true时：

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button button1 =(Button)findViewById(R.id.button1);
        button1.setOnLongClickListener(new OnLongClickListener(){
            public boolean onLongClick(View v) {
                Log.i("myinfo", "button长按事件。。。");
                return true;
            }
        });
        button1.setOnClickListener(new OnClickListener(){
            public void onClick(View v) {
                Log.i("myinfo", "button点击事件。。。");
            }
        });
}

运行结果：

当返回值为false时：

    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button button1 =(Button)findViewById(R.id.button1);
        button1.setOnLongClickListener(new OnLongClickListener(){
            public boolean onLongClick(View v) {
                Log.i("myinfo", "button长按事件。。。");
                return false;
            }
        });
        
        button1.setOnClickListener(new OnClickListener(){
            public void onClick(View v) {
                Log.i("myinfo", "button点击事件。。。");
            }
        });
}

运行结果：

长按button->

点击长按的时候回触发点击事件

所以通过长按事件中的返回true可以控制长按事件的传播；

 

---

 

3、滑动事件onTouchListener

        button1.setOnTouchListener(new OnTouchListener(){
            public boolean onTouch(View v, MotionEvent event) {
                // event对象记录了事件发生的现场情况
                int actionType=event.getAction();
                if(actionType==MotionEvent.ACTION_DOWN){
                    Log.i("myinfo", "touch 按下。。。。");
                }else if(actionType==MotionEvent.ACTION_MOVE){
                    Log.i("myinfo", "touch 移动。。。。");
                }else if(actionType==MotionEvent.ACTION_UP){
                    Log.i("myinfo", "touch 松开。。。。");
                }else{
                }
                return true;
            }
            
        });

运行结果：

小案例（用鼠标移动控制button的位置）：

 

main.xml:

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" 
    android:id="@+id/layout01"
    >

ThreeAndroidActivity.java:

public class ThreeAndroidActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        final Button button1 =(Button)findViewById(R.id.button1);
            ViewGroup viewGroup=(ViewGroup)findViewById(R.id.layout01);
            viewGroup.setOnTouchListener(new OnTouchListener(){

                public boolean onTouch(View v, MotionEvent event) {
                    int actionType=event.getAction();
                    if(actionType==MotionEvent.ACTION_DOWN){
                        Log.i("myinfo", "touch 按下。。。。");
                    }else if(actionType==MotionEvent.ACTION_MOVE){
                        Log.i("myinfo", "touch 移动。。。。");
                        button1.setX(event.getX());
                        button1.setY(event.getY());
                    }else if(actionType==MotionEvent.ACTION_UP){
                        Log.i("myinfo", "touch 松开。。。。");
                    }else{
                    }
                    return true;
                }
            });
    }
}

运行结果：（鼠标点击到哪里，button按钮就到哪里）button随着鼠标的移动而移动。

 

---

 

4、键盘事件onKeyListener

ThreeAndroidActivity .java:

public class ThreeAndroidActivity extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        final Button button1 =(Button)findViewById(R.id.button1);
        button1.setOnKeyListener(new OnKeyListener(){

            public boolean onKey(View v, int keyCode, KeyEvent event) {
                System.out.print(keyCode);
                return false;
            }
            
        });
    }
}

运行结果：

输出键盘中的按钮的ASCII码

 

小案例：通过awsd来控制button的位置：

ThreeAndroidActivity .java:

        button1.setOnKeyListener(new OnKeyListener(){
            public boolean onKey(View v, int keyCode, KeyEvent event) {
                //a:29; d:32; w:51;  s:47;
                if(29==keyCode){
                    button1.setX(button1.getX()-20);
                }else if(32==keyCode){
                    button1.setX(button1.getX()+20);
                }else if(51==keyCode){
                    button1.setY(button1.getY()-20);
                }else if(47==keyCode){
                    button1.setY(button1.getY()+20);
                }else {
                }
                return false;
            }
            
        });

---

 

5、焦点事件setOnFocusChangeListener

 

        button1.setOnFocusChangeListener(new OnFocusChangeListener(){

            public void onFocusChange(View v, boolean hasFocus) {
                Log.i("myinfo", "button   焦点事件。。。。。。。。");
            }
        });

运行的时候，通过点击tab让button获取焦点事件；

日志打印：

再创建一个button：

通过点击tab，可以使两个button间焦点的来回移动：