android脚步---Itent.ACTION_PICK ，startActivityForResult

public void onClick(View v) {
        // TODO Auto-generated method stub
        Intent intent = new Intent(Intent.ACTION_PICK);
        intent.setType("image/*");
        switch (v.getId()) {
        case R.id.btFirst:

            startActivityForResult(intent, 1);
        
            break;
        case R.id.btSecond:

            startActivityForResult(intent, 2);

            break;
        case R.id.btDetect:
            final String firstPath = etFirst.getText().toString();
            final String secondPath = etSecond.getText().toString();

然后重写方法，对应：

@Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // TODO Auto-generated method stub
        super.onActivityResult(requestCode, resultCode, data);
        if (data != null) {
            Cursor cursor = getContentResolver().query(data.getData(), null,
                    null, null, null);
            cursor.moveToFirst();
            int idx = cursor.getColumnIndex(ImageColumns.DATA);
            String fileSrc = cursor.getString(idx);
            if (requestCode == 1) {
                etFirst.setText(fileSrc);

            } else if (requestCode == 2) {
                etSecond.setText(fileSrc);

            }
            cursor.close();

        }
    }

Cursor cursor得到数据库指针 cursor，指向data.getData，像是一条条存储，cursor.moveToFirst();指向存储的第一条，int idx = cursor.getColumnIndex(ImageColumns.DATA);idx相当一个索引，指向(ImageColumns.DATA，

requestCode很重要，startActivityForResult(Intent intent, int requestCode)中startActivityForResult中两个参数对应的requestCode，

http://blog.csdn.net/chenzheng_java/article/details/6266135

代码中：Intent intent = new Intent(Intent.ACTION_PICK);

        android之Itent.ACTION_PICK  Intent.ACTION_GET_CONTENT妙用             

你是不是很多时候，想从弹出的电话本姓名列表中中查找到某个人，然后再获取该人的详细信息呢？

你是不是想选择从弹出的列表中选择一张图片，然后将其进行进一步的操作呢？

如果，你想，那你是不是很像知道，我们应该怎么让其弹出来一张选择列表，又应该怎么代码实现后边的操作呢？

Itent.ACTION_PICK  Intent.ACTION_GET_CONTENT 两者都可以完成类似的功能，让我们一起来看下例子

第一：Intent.ACTION_PICK

首先添加一个权限： <uses-permission android:name="android.permission.READ_CONTACTS"/>

发起一个 Contact Picker

Intent intent = new Intent(Intent.ACTION_PICK, People.CONTENT_URI);

startActivityForResult(intent, PICK_CONTACT);

然后：

重写方法

@Override 
public void onActivityResult(int reqCode, int resultCode, Intent data) 
  {  
      super.onActivityResult(reqCode, resultCode, data);  
        switch (reqCode) { 
             case (PICK_CONTACT) :      
             if (resultCode == Activity.RESULT_OK) {        
             Uri contactData = data.getData();        
             Cursor c =  managedQuery(contactData, null, null, null, null);        
             if (c.moveToFirst()) {          
                String name = c.getString(c.getColumnIndexOrThrow(People.NAME));          
                // TODO Whatever you want to do with the selected contact name.        
                                 }      
                      }      
               
      break;  
                
         } 
   } 

     其中cursor是数据库的知识，相当于数据库中的指针，query得到contactdata，
例如

String[] columns = new String[] {People.NAME}; 
int[] names = new int[] {R.id.row_entry}; 
mAdapter = new SimpleCursorAdapter(this, R.layout.mycontacts, C, columns, names）； 
setListAdapter(mAdapter); 

第二：Intent.ACTION_GET_CONTENT

 

我们可以发现，其实action_get_content是通过intent中设置的type属性来判断具体调用哪个程序的。

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("audio/*");
startActivity(Intent.createChooser(intent, "Select music"));

<span style="font-family: comic sans ms,sans-serif;"><span style="font-size: x-small;">Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("audio/*");
startActivity(Intent.createChooser(intent, "Select music"));</span></span>

Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
intent.setType("audio/*");
startActivity(Intent.createChooser(intent, "Select music"));

执行之 会弹出一个对话框 效果为：

 

其实 对于这段代码 大家应该都能猜出什么意思  现自己模拟并理解

[代码]

1. 定义TestActivity 用于根据传入Uri  播放目标

<span style="font-family: comic sans ms,sans-serif;"><span style="font-size: x-small;">public class TestActivity extends Activity {
    
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        this.setTitle("TestActivity");
        
        Intent i = this.getIntent();
        
        Uri u = i.getData();
        
        try {
            playMusic(u);
        } catch (IllegalArgumentException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SecurityException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IllegalStateException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
    
    public void playMusic(Uri uri) throws IllegalArgumentException, SecurityException, IllegalStateException, IOException{
        MediaPlayer mp = new MediaPlayer();
        mp.setDataSource(this, uri);
        mp.prepare();
        mp.start();
    }
}</span></span>

2. 在AndroidManifest 注册TestActivity

<span style="font-family: comic sans ms,sans-serif;"><span style="font-size: x-small;"><activity android:name=".TestActivity"
                  android:label="TestActivity">
            <intent-filter>
                <action android:name="android.intent.action.GET_CONTENT" />
                 <category android:name="android.intent.category.DEFAULT" />
                 <category android:name="android.intent.category.OPENABLE" />
                 <data android:mimeType="audio/music1" />
            </intent-filter>
        </activity></span></span>

3. 使用TestActivity

<span style="font-family: comic sans ms,sans-serif;"><span style="font-size: x-small;">public void sendChooser(){
        Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
        
        intent.setDataAndType(Uri.parse("file:///sdcard/DCIM/cc.mp3"), "audio/music1");

        startActivity(Intent.createChooser(intent, "Select music1 app"));
    }</span></span>

4. emulator 运行截图：

 

此外：

   //选择图片 requestCode 返回的标识

　　Intent innerIntent = new Intent(Intent.ACTION_GET_CONTENT); //"android.intent.action.GET_CONTENT"

　　innerIntent.setType(contentType); //查看类型 String IMAGE_UNSPECIFIED = "image/*";

　　Intent wrapperIntent = Intent.createChooser(innerIntent, null);

　　((Activity) context).startActivityForResult(wrapperIntent, requestCode);

 

　　//视频

　　Intent innerIntent = new Intent(Intent.ACTION_GET_CONTENT);

　　innerIntent.setType(contentType); //String VIDEO_UNSPECIFIED = "video/*";

　　Intent wrapperIntent = Intent.createChooser(innerIntent, null);

　　((Activity) context).startActivityForResult(wrapperIntent, requestCode);

 

　　//添加音频

　　Intent innerIntent = new Intent(Intent.ACTION_GET_CONTENT);

　　innerIntent.setType(contentType); //String VIDEO_UNSPECIFIED = "video/*";

　　Intent wrapperIntent = Intent.createChooser(innerIntent, null);

　　((Activity) context).startActivityForResult(wrapperIntent, requestCode);

 

　　//录音

　　Intent intent = new Intent(Intent.ACTION_GET_CONTENT);

　　intent.setType(ContentType.AUDIO_AMR); //String AUDIO_AMR = "audio/amr";

　　intent.setClassName("com.android.soundrecorder",

　　"com.android.soundrecorder.SoundRecorder");

　　((Activity) context).startActivityForResult(intent, requestCode);

 

　　//拍摄视频

　　int durationLimit = getVideoCaptureDurationLimit(); //SystemProperties.getInt("ro.media.enc.lprof.duration", 60);

　　Intent intent = new Intent(MediaStore.ACTION_VIDEO_CAPTURE);

　　intent.putExtra(MediaStore.EXTRA_VIDEO_QUALITY, 0);

　　intent.putExtra(MediaStore.EXTRA_SIZE_LIMIT, sizeLimit);

　　intent.putExtra(MediaStore.EXTRA_DURATION_LIMIT, durationLimit);

　　startActivityForResult(intent, REQUEST_CODE_TAKE_VIDEO);

 

　　//拍照 REQUEST_CODE_TAKE_PICTURE 为返回的标识

　　Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE); //"android.media.action.IMAGE_CAPTURE";

　　intent.putExtra(MediaStore.EXTRA_OUTPUT, Mms.ScrapSpace.CONTENT_URI); // output,Uri.parse("content://mms/scrapSpace");

　　startActivityForResult(intent, REQUEST_CODE_TAKE_PICTURE);