Android入门：基本控件（一）

概述

android的界面编程和swimg有很多类似的地方，几乎android的控件都在swimg出现过，在单个activity里编程一般只要修改源文件和main.xml。解释直接写在代码里。

1 Button

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:orientation="vertical" >

        <TextView
                android:id="@+id/MyTextView"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"/>
        <Button
                android:id="@+id/MyButton"
                android:text="点击产生随机数"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"/>
                

</LinearLayout>

ButtonActivity

package me.chendd.button;

import java.util.Random;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class AndroidButtonActivity extends Activity {
        /** Called when the activity is first created. */
  private TextView MyTextview = null;
  private Button MyButton = null;
  
        @Override
        public void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.main);
                MyTextview = (TextView)findViewById(R.id.MyTextView);
                MyButton = (Button)findViewById(R.id.MyButton);
                // 添加监听器
                MyButton.setOnClickListener(new ButtonListener());
        }
        // 内部类实现
        class ButtonListener implements OnClickListener {

    @Override
    public void onClick(View v) {
      // TODO Auto-generated method stub
      // 产生随机数
      String str = new Random().nextInt()+"";
      MyTextview.setText(str);      
    }
          
        }
}

2 ImageButton

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:orientation="vertical" >

        <TextView
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"/>
        <ImageButton
                android:id="@+id/MyImageButton"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="点击切换图片" />

</LinearLayout>

ImageButton

package me.chendd.p_w_picpathbutton;

import android.app.Activity;
import android.os.Bundle;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageButton;

public class AndroidImageButtonActivity extends Activity {
        /** Called when the activity is first created. */
  private ImageButton MyImageButton = null;
  
        @Override
        public void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.main);
                MyImageButton = (ImageButton) findViewById(R.id.MyImageButton);
                MyImageButton.setOnTouchListener(new OnTouchListener(){
                  
                  @Override
      public boolean onTouch(View v, MotionEvent event) {
        // TODO Auto-generated method stub
        if(event.getAction() == MotionEvent.ACTION_DOWN) {  
          // 注意此处v和MyImageButton都可以
          MyImageButton.setBackgroundResource(R.drawable.ic_launcher);
        } else if(event.getAction() == MotionEvent.ACTION_UP) {        
          MyImageButton.setBackgroundResource(R.drawable.icon);
        }
        return true;
      }
    });
        }
}

3 EditText

main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:orientation="vertical" >

        <TextView
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:text="@string/hello" />
        <!-- android:inputType="number"：输入类型为数字； -->
        <!-- android:maxLength="2"：输入最长为2； -->
        <!-- android:password="true" ：输入的形式为密码 -->
        <!-- android:numeric="integer"：输入整数 -->
        <EditText
                android:id="@+id/et"
                android:layout_width="fill_parent"
                android:layout_height="wrap_content"
                android:singleLine="true"
                android:text="@string/hello" />

</LinearLayout>

EditTextActivity

package me.chendd.edittext;

import android.app.Activity;
import android.os.Bundle;
import android.widget.EditText;

public class AndroidEditTextActivity extends Activity {
        /** Called when the activity is first created. */
  private EditText et = null;
  
        @Override
        public void onCreate(Bundle savedInstanceState) {
                super.onCreate(savedInstanceState);
                setContentView(R.layout.main);
                et = (EditText) findViewById(R.id.et);
        }
}