维尼少少08 常见事件响应的实现方式对比
常见的事件：
1、单击事件onClickListener
2、长按事件onLongClickListener
3、滑动事件onTouchListener
4、键盘事件onKeyListener
5、焦点事件setOnFocusChangeListener
常见的事件相应实现方式：
1、动态设置
例子：OnClickListener
main.xml:
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button"
/>
TWOAndroidActivity.java:
Button button=(Button)findViewById(R.id.button1);
button.setOnClickListener(new OnClickListener() {
//给button按钮绑定了一个listener，实现button按钮点击出现效果，执行onClick方法
public void onClick(View v) {
Toast.makeText(TWOAndroidActivity.this, "button被点击了", Toast.LENGTH_SHORT).show();
}
});
2、配置方式 仅限于onclick
main.xml:
<Button
android:id="@+id/button1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/msg"
android:onClick="test"
/>
TWOAndroidActivity.java:
Public void test(View view){
view.setX(view.getX()+10);
}
3、可复用方式（在onclick方法中判断哪个组件发生了相应事件）
Main.xml:
<Button
android:id="@+id/button1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Button"
android:onClick="test"
/>
TWOAndroidActivity.java
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button button1=(Button)findViewById(R.id.button1);
button1.setOnClickListener(myListener);
}
private View.OnClickListener myListener =new OnClickListener()
{
public void onClick(View v)
{
Toast.makeText(TWOAndroidActivity.this, "button1被点击了", Toast.LENGTH_SHORT).show();
}
};
好处：适用于多个button时:
main.xml:
<Button
android:id="@+id/button1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Button1"
android:onClick="test"/>
<Button
android:id="@+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button2" />
<Button
android:id="@+id/button3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Button3" />
TWOAndroidActivity.java :
public class TWOAndroidActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
Button button1=(Button)findViewById(R.id.button1);
Button button2=(Button)findViewById(R.id.button2);
Button button3=(Button)findViewById(R.id.button3);
button1.setOnClickListener(myListener);
button2.setOnClickListener(myListener);
button3.setOnClickListener(myListener);
}
private View.OnClickListener myListener =new OnClickListener(){
public void onClick(View v) {
Toast.makeText(TWOAndroidActivity.this, "button被点击了", Toast.LENGTH_SHORT).show();
switch(v.getId()){
case R.id.button1:Toast.makeText(TWOAndroidActivity.this, "button1被点击了", Toast.LENGTH_SHORT).show();
break;
case R.id.button2:Toast.makeText(TWOAndroidActivity.this, "button2被点击了", Toast.LENGTH_SHORT).show();
break;
case R.id.button3:Toast.makeText(TWOAndroidActivity.this, "button3被点击了", Toast.LENGTH_SHORT).show();
break;
}
}
};
}
运行结果：三个button只需要一个listener即可。
