如何创建动态文件视图？

Question

嗨我想创建动态文件查看图库图像，但我不知道如何创建动态文件视图.....请帮我......给我你的建议.....

这是我的相册查看本次代码：

package ImageViewExample.ImageViewExample; 

import android.app.Activity; 
import android.content.Context; 
import android.content.Intent; 
import android.database.Cursor; 
import android.net.Uri; 
import android.os.Bundle; 
import android.provider.MediaStore; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.AdapterView; 
import android.widget.BaseAdapter; 
import android.widget.Gallery; 
//import android.widget.GridView; 
import android.widget.ImageView; 
import android.widget.AdapterView.OnItemClickListener; 

public class ImageViewExample extends Activity { 
    /** Called when the activity is first created. */ 
    private Cursor imagecursor, actualimagecursor; 
    private int image_column_index, actual_image_column_index; 
    Gallery imagegrid; 
    private int count; 
    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 
     init_phone_image_grid(); 
    } 
    private void init_phone_image_grid() { 
     String[] img = { MediaStore.Images.Thumbnails._ID }; 
     imagecursor = managedQuery(
    MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, img, null, 
    null, MediaStore.Images.Thumbnails.IMAGE_ID + ""); 
     image_column_index = imagecursor 
    .getColumnIndexOrThrow(MediaStore.Images.Thumbnails._ID); 
     count = imagecursor.getCount(); 
     imagegrid = (Gallery) findViewById(R.id.PhoneImageGrid); 
     imagegrid.setAdapter(new ImageAdapter(getApplicationContext())); 
     imagegrid.setOnItemClickListener(new OnItemClickListener() { 
       public void onItemClick(AdapterView parent, View v, 
    int position, long id) { 
        System.gc(); 
        String[] proj = { MediaStore.Images.Media.DATA }; 
        actualimagecursor = managedQuery(
    MediaStore.Images.Media.EXTERNAL_CONTENT_URI, proj, 
    null, null, null); 
        actual_image_column_index = actualimagecursor 
    .getColumnIndexOrThrow(MediaStore.Images.Media.DATA); 
        actualimagecursor.moveToPosition(position); 
        String i = actualimagecursor.getString(actual_image_column_index); 
        System.gc(); 
        Intent intent = new Intent(getApplicationContext(),  
    ViewImage.class); 
        intent.putExtra("filename", i); 
        startActivity(intent); 
       } 
     }); 
     } 


    public class ImageAdapter extends BaseAdapter { 
     private    Context mContext; 
     public ImageAdapter(Context c) { 
       mContext = c; 
     } 
     public int getCount() { 
       return count; 
     } 
     public Object getItem(int position) { 
       return position; 
     } 
     public long getItemId(int position) { 
       return position; 
     } 
     public View getView(int position,View convertView,ViewGroup parent) { 
       System.gc(); 
       ImageView i = new ImageView(mContext.getApplicationContext()); 
       if (convertView == null) { 
        imagecursor.moveToPosition(position); 
        int id = imagecursor.getInt(image_column_index); 
        i.setImageURI(Uri.withAppendedPath(
     MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, "" 
    + id)); 
        i.setScaleType(ImageView.ScaleType.CENTER_CROP); 
        i.setLayoutParams(new Gallery.LayoutParams(110,110)); 
       } 
       else { 
        i = (ImageView) convertView; 
       } 
       return i; 
     } 
    } 
    } 

这是我的XML编码：

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:orientation="vertical" 
android:layout_width="fill_parent" 
android:layout_height="fill_parent"> 
<Gallery xmlns:android="http://schemas.android.com/apk/res/android" 
android:id="@+id/PhoneImageGrid" 
android:layout_width="fill_parent" 
android:layout_height="fill_parent" 
android:numColumns="auto_fit" 
android:verticalSpacing="10dp" 
android:horizontalSpacing="10dp" 
android:columnWidth="90dp" 
android:stretchMode="columnWidth" 
android:spacing="16dp" 
/> 
</LinearLayout> 

日志猫错误：

04-25 23:06:14.329: INFO/Process(391): Sending signal. PID: 391 SIG: 9 
04-25 23:06:14.389: INFO/ActivityManager(63): Process 
ImageViewExample.ImageViewExample (pid 391) has died. 
04-25 23:06:14.800: WARN/InputManagerService(63): Window already focused, ignoring 
focus gain of: com.android.internal.view.IInputMethodClient$Stub$Proxy@43fdc730 
04-25 23:06:26.009: DEBUG/AndroidRuntime(403): >>>>>>>>>>>>>> AndroidRuntime START 
<<<<<<<<<<<<<< 
04-25 23:06:26.019: DEBUG/AndroidRuntime(403): CheckJNI is ON 
04-25 23:06:26.580: DEBUG/AndroidRuntime(403): --- registering native functions --- 
04-25 23:06:28.259: DEBUG/AndroidRuntime(403): Shutting down VM 
04-25 23:06:28.300: DEBUG/dalvikvm(403): Debugger has detached; object registry had 1 
entries 
04-25 23:06:28.329: INFO/AndroidRuntime(403): NOTE: attach of thread 'Binder Thread 
#3' failed 
04-25 23:06:29.389: DEBUG/AndroidRuntime(411): >>>>>>>>>>>>>> AndroidRuntime START 
<<<<<<<<<<<<<< 
04-25 23:06:29.389: DEBUG/AndroidRuntime(411): CheckJNI is ON 
04-25 23:06:29.839: DEBUG/AndroidRuntime(411): --- registering native functions --- 
04-25 23:06:31.359: INFO/ActivityManager(63): Starting activity: Intent { 
act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 
cmp=ImageViewExample.ImageViewExample/.ImageViewExample } 
04-25 23:06:31.610: DEBUG/AndroidRuntime(411): Shutting down VM 
04-25 23:06:31.730: DEBUG/dalvikvm(411): Debugger has detached; object registry had 1 
entries 
04-25 23:06:31.786: INFO/AndroidRuntime(411): NOTE: attach of thread 'Binder Thread 
#3' failed 
04-25 23:06:32.019: INFO/ActivityManager(63): Start proc 
ImageViewExample.ImageViewExample for activity 
ImageViewExample.ImageViewExample/.ImageViewExample: pid=418 uid=10050 gids={} 
04-25 23:06:33.169: DEBUG/AndroidRuntime(418): Shutting down VM 
04-25 23:06:33.169: WARN/dalvikvm(418): threadid=1: thread exiting with uncaught  
exception (group=0x4001d800) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418): FATAL EXCEPTION: main 
04-25 23:06:33.229: ERROR/AndroidRuntime(418): java.lang.RuntimeException: Unable to 
start activity 
ComponentInfo{ImageViewExample.ImageViewExample/ImageViewExample.ImageViewExample 
.ImageViewExample}: java.lang.NullPointerException 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  at 
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  at  
android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  at 
android.app.ActivityThread.access$2300(ActivityThread.java:125) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  at 
android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  at  
android.os.Handler.dispatchMessage(Handler.java:99) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  at 
android.os.Looper.loop(Looper.java:123) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  at  
android.app.ActivityThread.main(ActivityThread.java:4627) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  at 
java.lang.reflect.Method.invokeNative(Native Method) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  at 
java.lang.reflect.Method.invoke(Method.java:521) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  at 
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  at 
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  at 
dalvik.system.NativeStart.main(Native Method) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418): Caused by: 
java.lang.NullPointerException 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  at 
ImageViewExample.ImageViewExample.MyImageView.<init>(MyImageView.java:32) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  at 
ImageViewExample.ImageViewExample.ImageViewExample.onCreate(ImageViewExample.java:28) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  at 
android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  at 
android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627) 
04-25 23:06:33.229: ERROR/AndroidRuntime(418):  ... 11 more 
04-25 23:06:33.279: WARN/ActivityManager(63): Force finishing activity 
ImageViewExample.ImageViewExample/.ImageViewExample 
04-25 23:06:33.839: WARN/ActivityManager(63): Activity pause timeout for 
HistoryRecord{4403fb30 ImageViewExample.ImageViewExample/.ImageViewExample} 
04-25 23:06:45.281: WARN/ActivityManager(63): Activity destroy timeout for 
HistoryRecord{4403fb30 ImageViewExample.ImageViewExample/.ImageViewExample} 
04-25 23:10:06.659: DEBUG/SntpClient(63): request time failed: 
java.net.SocketException: 
Address family not supported by protocol 

Answer 1

import android.content.Context; 
import android.graphics.Canvas; 
import android.graphics.drawable.BitmapDrawable; 
import android.util.AttributeSet; 
import android.util.Log; 
import android.view.MotionEvent; 
import android.view.ScaleGestureDetector; 
import android.view.View; 

public class MyImageView extends View { 

private static final int INVALID_POINTER_ID = -1; 

    private Drawable mImage; 
    private float mPosX; 
    private float mPosY; 

    private float mLastTouchX; 
    private float mLastTouchY; 
    private int mActivePointerId = INVALID_POINTER_ID; 

    private ScaleGestureDetector mScaleDetector; 
    private float mScaleFactor = 1.f; 

    public MyImageView(Context context) { 
     this(context, null, 0); 
    mImage = Drawable.createFromPath("/sdcard/filename"); 

     mImage.setBounds(0, 0, width, height); 
    } 

    public MyImageView(Context context, AttributeSet attrs) { 
     this(context, attrs, 0); 
    } 

    public MyImageView(Context context, AttributeSet attrs, int defStyle) { 
     super(context, attrs, defStyle); 
     mScaleDetector = new ScaleGestureDetector(context, new ScaleListener()); 
    } 

    @Override 
    public boolean onTouchEvent(MotionEvent ev) { 
     // Let the ScaleGestureDetector inspect all events. 
     mScaleDetector.onTouchEvent(ev); 

     final int action = ev.getAction(); 
     switch (action & MotionEvent.ACTION_MASK) { 
     case MotionEvent.ACTION_DOWN: { 
      final float x = ev.getX(); 
      final float y = ev.getY(); 

      mLastTouchX = x; 
      mLastTouchY = y; 
      mActivePointerId = ev.getPointerId(0); 
      break; 
     } 

     case MotionEvent.ACTION_MOVE: { 
      final int pointerIndex = ev.findPointerIndex(mActivePointerId); 
      final float x = ev.getX(pointerIndex); 
      final float y = ev.getY(pointerIndex); 

      // Only move if the ScaleGestureDetector isn't processing a gesture. 
      if (!mScaleDetector.isInProgress()) { 
       final float dx = x - mLastTouchX; 
       final float dy = y - mLastTouchY; 

       mPosX += dx; 
       mPosY += dy; 

       invalidate(); 
      } 

      mLastTouchX = x; 
      mLastTouchY = y; 

      break; 
     } 

     case MotionEvent.ACTION_UP: { 
      mActivePointerId = INVALID_POINTER_ID; 
      break; 
     } 

     case MotionEvent.ACTION_CANCEL: { 
      mActivePointerId = INVALID_POINTER_ID; 
      break; 
     } 

     case MotionEvent.ACTION_POINTER_UP: { 
      final int pointerIndex = (ev.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) 
        >> MotionEvent.ACTION_POINTER_INDEX_SHIFT; 
      final int pointerId = ev.getPointerId(pointerIndex); 
      if (pointerId == mActivePointerId) { 
       // This was our active pointer going up. Choose a new 
       // active pointer and adjust accordingly. 
       final int newPointerIndex = pointerIndex == 0 ? 1 : 0; 
       mLastTouchX = ev.getX(newPointerIndex); 
       mLastTouchY = ev.getY(newPointerIndex); 
       mActivePointerId = ev.getPointerId(newPointerIndex); 
      } 
      break; 
     } 
     } 

     return true; 
    } 

    @Override 
    public void onDraw(Canvas canvas) { 
     super.onDraw(canvas); 

     canvas.save(); 
     Log.d("DEBUG", "X: "+mPosX+" Y: "+mPosY); 
     canvas.translate(mPosX, mPosY); 
     canvas.scale(mScaleFactor, mScaleFactor); 
     mImage.draw(canvas); 
     canvas.restore(); 
    } 

    private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener { 
     @Override 
     public boolean onScale(ScaleGestureDetector detector) { 
      mScaleFactor *= detector.getScaleFactor(); 

      // Don't let the object get too small or too large. 
      mScaleFactor = Math.max(0.1f, Math.min(mScaleFactor, 10.0f)); 

      invalidate(); 
      return true; 
     } 
    } 

} 

要在您的活动中调用setContentView（new MyImageView（this））;