Android 控件练习 (2)

简易的按钮事件

Button 事件处理

activity_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/show_TextView"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello" />

    <Button
        android:id="@+id/Click_Button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="点击" />

</LinearLayout>

MainActivity.java

package com.example.demo;

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

public class MainActivity extends Activity {
    TextView show;
    Button press;
    int i = 0;

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        show = (TextView) findViewById(R.id.show_TextView);
        press = (Button) findViewById(R.id.Click_Button);

        press.setOnClickListener(new Button.OnClickListener() {
            @Override
            public void onClick(View v) {
                i++;
                if (i % 2 == 0) {
                    show.setText("Hi , Google Android!");
                } else {
                    show.setText("Hi , Michael!");
                }
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }
}

手机页面的转换

setContentView 的应用

activity_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:background="@color/black" >

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_weight="2"
        android:orientation="vertical" >

        <TextView
            android:id="@+id/text1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/layout1"
            android:textSize="24sp" >
        </TextView>
    </LinearLayout>

       <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_weight="1"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/button1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Go to Layout2" >
        </Button>
    </LinearLayout>

</LinearLayout>

mylayout.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:background="@color/white" >

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_weight="2"
        android:orientation="vertical" >

        <TextView
            android:id="@+id/text2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="@string/layout2"
            android:textColor="@color/black"
            android:textSize="24sp" >
        </TextView>
    </LinearLayout>

    <LinearLayout
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_weight="1"
        android:orientation="horizontal" >

        <Button
            android:id="@+id/button2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:text="Go to Layout1" >
        </Button>
    </LinearLayout>

</LinearLayout>

string_color.xml

    <string name="layout1">this is Layout 1</string>
    <string name="layout2">This is Layout 2</string>

    <color name="black">#000000</color>
    <color name="white">#FFFFFFFF</color>

MainActivity.java

package com.example.demo;

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

public class MainActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        /* 以findViewById()取得Button 对象，并添加onClickListener */
        Button b1 = (Button) findViewById(R.id.button1);
        b1.setOnClickListener(new Button.OnClickListener() {
            public void onClick(View v) {
                jumpToLayout2();// 调用跳转方法jumpToLayout2()
            }
        });
    }

    /*
     * method jumpToLayout2：将 layout 由 main.xml 切 换 成 mylayout.xml
     */
    public void jumpToLayout2() {
        /* 将layout 改成mylayout.xml */
        setContentView(R.layout.mylayout);
        /* 以findViewById()取得Button 对象，并添加onClickListener */
        Button b2 = (Button) findViewById(R.id.button2);
        b2.setOnClickListener(new Button.OnClickListener() {
            public void onClick(View v) {
                jumpToLayout1();// 调用跳转方法jumpToLayout1()
            }
        });
    } /*
     * method jumpToLayout1：将 layout 由 mylayout.xml 切 换 成main.xml
     */

    public void jumpToLayout1() {
        /* 将layout 改成main.xml */
        setContentView(R.layout.activity_main);
        /* 以findViewById()取得Button 对象，并添加onClickListener */
        Button b1 = (Button) findViewById(R.id.button1);
        b1.setOnClickListener(new Button.OnClickListener() {
            public void onClick(View v) {
                jumpToLayout2();// 调用跳转方法jumpToLayout2()
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }
}

 调用另一个Activity

 Intent 对象的使用

string_color.xml

    <string name="act1">This is Activity 1!</string>
    <string name="act2">This is Activity 2!</string>

    <color name="black">#000000</color>
    <color name="white">#FFFFFFFF</color>

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@color/black" >

    <TextView
        android:id="@+id/text1"
        android:layout_width="186px"
        android:layout_height="29px"
        android:layout_x="70px"
        android:layout_y="32px"
        android:text="@string/act1"
        android:textSize="24sp" >
    </TextView>

    <Button
        android:id="@+id/button1"
        android:layout_width="118px"
        android:layout_height="wrap_content"
        android:layout_x="100px"
        android:layout_y="82px"
        android:text="Go to Activity2" >
    </Button>

</AbsoluteLayout>

secondlayout.xml

<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:background="@color/white" >

    <TextView
        android:id="@+id/text2"
        android:layout_width="186px"
        android:layout_height="29px"
        android:layout_x="70px"
        android:layout_y="32px"
        android:text="@string/act2"
        android:textColor="@color/black"
        android:textSize="24sp" >
    </TextView>

    <Button
        android:id="@+id/button2"
        android:layout_width="118px"
        android:layout_height="wrap_content"
        android:layout_x="100px"
        android:layout_y="82px"
        android:text="Go to Activity1" >
    </Button>

</AbsoluteLayout>

MainActivity.java

package com.example.demo;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.widget.Button;

public class MainActivity extends Activity {

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        /* 载入main.xml Layout */
        setContentView(R.layout.activity_main);
        /* 以findViewById()取得Button 对象，并添加onClickListener */
        Button b1 = (Button) findViewById(R.id.button1);
        b1.setOnClickListener(new Button.OnClickListener() {
            public void onClick(View v) {
                /* new 一个Intent 对象，并指定要启动的class */
                Intent intent = new Intent();
                intent.setClass(MainActivity.this, SecondActivity.class);
                /* 调用一个新的Activity */
                startActivity(intent);
                /* 关闭原本的Activity */
                MainActivity.this.finish();
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.activity_main, menu);
        return true;
    }
}

SecondActivity.java

package com.example.demo;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;

public class SecondActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        /* 载入mylayout.xml Layout */
        setContentView(R.layout.secondlayout);
        /* 以findViewById()取得Button 对象，并添加onClickListener */
        Button b2 = (Button) findViewById(R.id.button2);
        b2.setOnClickListener(new Button.OnClickListener() {
            public void onClick(View v) {
                /* new 一个Intent 对象，并指定要启动的class */
                Intent intent = new Intent();
                intent.setClass(SecondActivity.this, MainActivity.class);
                /* 调用一个新的Activity */
                startActivity(intent);
                /* 关闭原本的Activity */
                SecondActivity.this.finish();
            }
        });
    }
}

在AndroidManifest.xml 文件中添加SecondActivity

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.example.demo"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="10"
        android:targetSdkVersion="15" />

    <application
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/title_activity_main" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name="SecondActivity" >
        </activity>
    </application>

</manifest>

 专业相框设计:

ImageView 的堆叠应用

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/widget34"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" > <!-- 创建第一个ImageView (第二层图片) -->

    <ImageView
        android:id="@+id/myImageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_x="0px"
        android:layout_y="36px" />
    <!-- 创建第二个ImageView (第一层图片) -->

    <ImageView
        android:id="@+id/myImageView2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_x="0px"
        android:layout_y="36px" />
    <!-- 创建第一个Button -->

    <Button
        android:id="@+id/myButton1"
        android:layout_width="105px"
        android:layout_height="66px"
        android:layout_x="9px"
        android:layout_y="356px"
        myButton1=""
        android:text="pic1" />
    <!-- 创建第二个Button -->

    <Button
        android:id="@+id/myButton2"
        android:layout_width="105px"
        android:layout_height="66px"
        android:layout_x="179px"
        android:layout_y="356px"
        android:text="pic2" />

</AbsoluteLayout>

MainActivity.java

package com.example.demo;

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

public class MainActivity extends Activity {

    /** Called when the activity is first created. */
    /* 声明Button、ImageView 对象 */
    private ImageView mImageView01;
    private ImageView mImageView02;
    private Button mButton01;
    private Button mButton02;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        /* 取得Button、ImageView 对象 */
        mImageView01 = (ImageView) findViewById(R.id.myImageView1);
        mImageView02 = (ImageView) findViewById(R.id.myImageView2);
        mButton01 = (Button) findViewById(R.id.myButton1);
        mButton02 = (Button) findViewById(R.id.myButton2);
        /* 设置ImageView 背景图 */
        mImageView01.setImageDrawable(getResources().getDrawable(
                R.drawable.right));
        mImageView02.setImageDrawable(getResources().getDrawable(
                R.drawable.photo));
        /* 用OnClickListener 事件来启动 */
        mButton01.setOnClickListener(new Button.OnClickListener() {
            @Override
            public void onClick(View v) {
                /* 当启动后， ImageView 立刻换背景图 */
                mImageView01.setImageDrawable(getResources().getDrawable(
                        R.drawable.right));
            }
        });
        mButton02.setOnClickListener(new Button.OnClickListener() {
            @Override
            public void onClick(View v) {
                mImageView01.setImageDrawable(getResources().getDrawable(
                        R.drawable.left));
            }
        });
    }
}

相簿浏览Gallery

Gallery 与衍生BaseAdapter 容器

strings.xml

   <declare-styleable name="Gallery">
        <attr name="android:galleryItemBackground" />
    </declare-styleable>
    <!-- 定义layout 外部resource 的xml 文件，用来改变layout 的背景图。 -->

修改activity_main.xml布局，添加一个Gallery 和一个ImageView

<?xml version="1.0" encoding="utf-8"?>
<AbsoluteLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/widget_absolutelayout"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <Gallery
        android:id="@+id/Gallery_preView"
        android:layout_width="fill_parent"
        android:layout_height="143px"

        android:layout_x="0px"
        android:layout_y="51px" >
    </Gallery>

    <ImageView
        android:id="@+id/ImageView_photo"
        android:layout_width="239px"
        android:layout_height="218px"
        android:layout_x="38px"
        android:layout_y="184px" >
    </ImageView>

</AbsoluteLayout>

新建一个myImageAdapter 类--Gallery 的适配器，它继承于BaseAdapter 类.实现相簿浏览效果

package com.example.demo;

import android.content.Context;
import android.content.res.TypedArray;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.Gallery;
import android.widget.ImageView;

public class myImageAdapter extends BaseAdapter {
    /* 变量声明 */
    int mGalleryItemBackground;
    private Context context;// 上下文
    /* 构建一Integer array 并取得预加载Drawable 的图片id */
    public Integer[] myImageIds = { R.drawable.photo1, R.drawable.photo2,
            R.drawable.photo3, R.drawable.photo4, R.drawable.photo5,
            R.drawable.photo6, };

    /* 自定义的构造方法 */
    public myImageAdapter(Context context) {
        // TODO Auto-generated constructor stub
        this.context = context;
        /*
         * 使用在res/values/attrs.xml 中的<declare-styleable>定义的Gallery 属性.
         */
        TypedArray typed_array = context
                .obtainStyledAttributes(R.styleable.Gallery);
        /* 取得Gallery 属性的Index id */
        mGalleryItemBackground = typed_array.getResourceId(
                R.styleable.Gallery_android_galleryItemBackground, 0);
        /* 让对象的styleable 属性能够反复使用 */
        typed_array.recycle();
    }/*
     * 重 写 的 方 法 getCount,返 回 图 片 数 目
     */

    @Override
    public int getCount() {
        // TODO Auto-generated method stub
        return myImageIds.length;
    }

    @Override
    public Object getItem(int position) {
        // TODO Auto-generated method stub
        return position;
    }

    @Override
    public long getItemId(int position) {
        // TODO Auto-generated method stub
        return position;
    }

    /*
     * 重 写 的 方 法 getView,返 回 一 View 对 象
     */
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        // TODO Auto-generated method stub
        /* 产生ImageView 对象 */
        ImageView imageview = new ImageView(context);
        /* 设置图片给imageView 对象 */
        imageview.setImageResource(myImageIds[position]);/* 重新设置图片的宽高 */
        imageview.setScaleType(ImageView.ScaleType.FIT_XY);
        /* 重新设置Layout 的宽高 */
        imageview.setLayoutParams(new Gallery.LayoutParams(128, 128));
        /* 设置Gallery 背景图 */
        imageview.setBackgroundResource(mGalleryItemBackground);
        /* 返回imageView 对象 */
        return imageview;
    }
}

修改mainActivity.java，添加Gallery 相关操作

package com.example.demo;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Gallery;
import android.widget.ImageView;
import android.widget.Toast;

public class MainActivity extends Activity {

    /** Called when the activity is first created. */
    /* 定义要使用的对象 */
    private Gallery gallery;
    private ImageView imageview;
    private myImageAdapter imageadapter;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        imageadapter = new myImageAdapter(this);
        /* 通过findViewById 取得资源对象 */
        gallery = (Gallery) findViewById(R.id.Gallery_preView);
        imageview = (ImageView) findViewById(R.id.ImageView_photo);
        /* 给Gallery设置适配器把Ex_Ctrl_10ME类传入参数 */
        gallery.setAdapter(imageadapter);
        /* 设置Gallery的点击事件监听器 */
        gallery.setOnItemClickListener(new Gallery.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View v,
                    int position, long id) {
                // TODO Auto-generated method stub
                /* 显示该图片是几号 */
                Toast.makeText(MainActivity.this, "这是图片：" + position + "号",
                        Toast.LENGTH_SHORT).show();
                /* 设置大图片 */
                imageview
                        .setBackgroundResource(imageadapter.myImageIds[position]);
            }
        });
    }
}

 文件搜索引擎FileSearch

SDCard 中，文件搜索与File 类

activity_main.xml

<AbsoluteLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/widget0"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

    <Button
        android:id="@+id/Button_Search"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_x="253px"
        android:layout_y="5px"
        android:text="@string/toSearch" >
    </Button>

    <EditText
        android:id="@+id/input_KEY_EditText"
        android:layout_width="112px"
        android:layout_height="52px"
        android:layout_x="119px"
        android:layout_y="4px"
        android:textSize="18sp" >
    </EditText>

    <TextView
        android:id="@+id/TextView_showIn"
        android:layout_width="103px"
        android:layout_height="29px"
        android:layout_x="5px"
        android:layout_y="16px"
        android:text="@string/showInput"
        android:textSize="20sp" >
    </TextView>

    <TextView
        android:id="@+id/TextView_Result"
        android:layout_width="fill_parent"
        android:layout_height="370px"
        android:layout_x="0px"
        android:layout_y="60px" >
    </TextView>

</AbsoluteLayout>

strings.xml

<resources>

    <string name="app_name">Demo</string>
    <string name="hello_world">Hello world!</string>
    <string name="menu_settings">Settings</string>
    <string name="title_activity_main">MainActivity</string>
    <string name="showInput">输入关键字</string>
    <string name="toSearch">搜索</string>
    <string name="info">系统SDCard目录文件路径:\n</string>
    <string name="pleaseInput">请输入关键字!!</string>
    <string name="notFond">没有找到相关文件!!</string>
    <string name="pathError">读取路径出错!!</string>

</resources>

MainActivity.java

package com.example.demo;

import java.io.File;

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

public class MainActivity extends Activity implements Button.OnClickListener {
    /** Called when the activity is first created. */
    /* 定义程序要使用的类对象 */
    private File file;
    private String path;
    private String info;
    private String theKey_formInput;
    private TextView show_Result;
    private EditText input_SearchKey_Edit;
    private Button toSearch_Button;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        /* 通过findViewById()获取XML中的UI对象 */
        show_Result = (TextView) findViewById(R.id.TextView_Result);
        input_SearchKey_Edit = (EditText) findViewById(R.id.input_KEY_EditText);
        toSearch_Button = (Button) findViewById(R.id.Button_Search);
        /* 为搜索按钮添加点击事件监听器 */
        toSearch_Button.setOnClickListener(this);
        /* 初始化一个Field 对象，指定路径为/sdcard */
        file = new File("/sdcard");
        /* 从xml中获取字符串 */
        info = getString(R.string.info);
    }

    /*
     * 按 钮 点 击 事 件 处 理
     */
    public void onClick(View v) {
        // TODO Auto-generated method stub
        /* 清空 */
        path = "";
        show_Result.setText("");
        /* 取得输入框中的要查询的Key */
        theKey_formInput = input_SearchKey_Edit.getText().toString();
        /* 浏览文件 */
        BrowserFile(file);
    } /*
     * 浏 览 文 件 方 法
     */

    public void BrowserFile(File file) {
        if (theKey_formInput.equals("")) {
            /* 如果输入框没有输入点击搜索按钮，提示输入 */
            Toast.makeText(this, getString(R.string.pleaseInput),
                    Toast.LENGTH_SHORT).show();
        } else {
            /* 开始搜索文件 */
            ToSearchFiles(file);
            /* 搜索完毕后，如果搜到结果为空，提示没有找到 */
            if (show_Result.getText().equals("")) {
                Toast.makeText(this, getString(R.string.notFond),
                        Toast.LENGTH_SHORT).show();
            }
        }
    }/*
     * 开 始 搜 索 文 件 方 法
     */

    public void ToSearchFiles(File file) {
        /* 定义一个File文件数组，用来存放/sdcard目录下的文件或文件夹 */
        File[] the_Files = file.listFiles();
        /* 通过遍历所有文件和文件夹 */
        for (File tempF : the_Files) {
            if (tempF.isDirectory()) {
                ToSearchFiles(tempF);
                /* 如果是文件夹的话继续遍历搜索 */
            } else {
                try {
                    /* 是文件，进行比较，如果文件名称中包含输入搜索Key，则返回大于-1的值 */
                    if (tempF.getName().indexOf(theKey_formInput) > -1) {
                        /* 获取符合条件文件的路径，进行累加 */
                        path += "\n" + tempF.getPath();
                        /* 显示结果的TextView显示信息和搜索到的路径 */
                        show_Result.setText(info + path);
                    }
                } catch (Exception e) {
                    // TODO: handle exception
                    /* 如果路径找不到，提示出错 */
                    Toast.makeText(this, getString(R.string.pathError),
                            Toast.LENGTH_SHORT).show();
                }
            }
        }
    }
}

----