android应用开发详解（六）--------------事件处理机制（续）

1、工程目录

2、TestEventActivity.java

package com.example.test_event;

import android.os.Bundle;
import android.app.Activity;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnFocusChangeListener;
import android.view.View.OnKeyListener;
import android.widget.Button;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.CompoundButton.OnCheckedChangeListener;
import android.widget.EditText;
//import android.widget.TextView;
import android.widget.Toast;

public class TestEventActivity extends Activity {
	// private TextView myTextview1, myTextview2, myTextView3;
	private Button myButton1, myButton2;
	private EditText myEditText1, myEditText2;
	private CheckBox myCheckbox1;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.test_event);
		// myTextview1 = (TextView) findViewById(R.id.textviewLayout01);
		// myTextview2 = (TextView) findViewById(R.id.textviewLayout02);
		// myTextView3 = (TextView) findViewById(R.id.textviewLayout03);
		myButton1 = (Button) findViewById(R.id.buttonLayout01);
		myButton2 = (Button) findViewById(R.id.buttonLayout02);
		myEditText1 = (EditText) findViewById(R.id.edittextLayout01);
		myEditText2 = (EditText) findViewById(R.id.editviewLayout02);
		myCheckbox1 = (CheckBox) findViewById(R.id.checkboxLayout01);
		// 编辑文本框的按键事件
		myEditText1.setOnKeyListener(new OnKeyListener() {

			@Override
			public boolean onKey(View arg0, int arg1, KeyEvent arg2) {
				// TODO Auto-generated method stub
				myEditText1.setText("");
				return false;
			}
		});
		myEditText2.setOnKeyListener(new OnKeyListener() {

			@Override
			public boolean onKey(View arg0, int arg1, KeyEvent arg2) {
				// TODO Auto-generated method stub
				myEditText2.setText("");
				return false;
			}
		});
		// 编辑文本框的焦点事件
		myEditText1.setOnFocusChangeListener(new OnFocusChangeListener() {

			@Override
			public void onFocusChange(View arg0, boolean arg1) {
				// TODO Auto-generated method stub
				Toast.makeText(getApplicationContext(), myEditText1.getText(),
						Toast.LENGTH_LONG).show();

			}
		});
		myEditText2.setOnFocusChangeListener(new OnFocusChangeListener() {

			@Override
			public void onFocusChange(View arg0, boolean arg1) {
				// TODO Auto-generated method stub
				Toast.makeText(getApplicationContext(), myEditText2.getText(),
						Toast.LENGTH_LONG).show();

			}
		});
		// 多选框的选择事件
		myCheckbox1.setOnCheckedChangeListener(new OnCheckedChangeListener() {

			@Override
			public void onCheckedChanged(CompoundButton arg0, boolean arg1) {
				// TODO Auto-generated method stub
				Toast.makeText(getApplicationContext(),
						myCheckbox1.isChecked() + "", Toast.LENGTH_LONG).show();
			}
		});
		// 按钮的选择事件
		myButton1.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View arg0) {
				// TODO Auto-generated method stub
				Toast.makeText(getApplicationContext(), myButton1.getText(),
						Toast.LENGTH_LONG).show();
			}
		});
		myButton2.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View arg0) {
				// TODO Auto-generated method stub
				Toast.makeText(getApplicationContext(), myButton2.getText(),
						Toast.LENGTH_LONG).show();
			}
		});
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.test_event, menu);
		return true;
	}

}

3、布局文件

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <TableLayout
        android:id="@+id/myTableLayout"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >

        <TableRow>

            <TextView
                android:id="@+id/textviewLayout01"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="用户名称" />

            <EditText
                android:id="@+id/edittextLayout01"
                android:layout_width="fill_parent"
                android:scrollHorizontally="true"
                android:text="admin" />
        </TableRow>

        <TableRow>

            <TextView
                android:id="@+id/textviewLayout02"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="用户密码" />

            <EditText
                android:id="@+id/editviewLayout02"
                android:layout_width="fill_parent"
                android:password="true"
                android:scrollHorizontally="true"
                android:text="123" />
        </TableRow>

        <TableRow>

            <TextView
                android:id="@+id/textviewLayout03"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="自动登录" />

            <CheckBox
                android:id="@+id/checkboxLayout01"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content" />
        </TableRow>

        <TableRow>

            <Button
                android:id="@+id/buttonLayout01"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="登录" />

            <Button
                android:id="@+id/buttonLayout02"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="取消" />
        </TableRow>
    </TableLayout>

</LinearLayout>

【知识】

android中常见的事件监听器：

(1)点击事件View.onClickListener：当用户碰触到某个组件或者方向键被按下时产生该事件，处理方法是onClick()

(2)焦点事件View.OnFocusChangeListener：组件得到或者失去焦点时产生该事件，处理方法是onFocusChange()

(3)按键事件View.OnKeyListener：用户按下或者释放设备上的某个按键时产生，处理方法onKey()

(4)碰触事件View.OnTouchListener：设备具有碰触功能时，碰触屏幕产生该事件，处理方法onTouch()

(5)创建上下文菜单事件View.OnCreateContextMenuListener：创建上下文菜单时产生该事件，处理方法是onCreateContextMenu()

事件处理步骤：

(1)创建事件监听器

(2)给要响应事件的组件注册事件监听器

(3)在事件处理方法中编写实现代码