android瀏覽圖像

Question

我正在研究android中的聯繫人列表項目，我想做一個瀏覽按鈕來瀏覽圖像並將其保存在我的數據庫中，以便每次聯繫。然後我想在屏幕上顯示圖像。 你能給我一個很好的例子或教程如何瀏覽圖像並保存/從數據庫中檢索？

首先，我試圖讓程序瀏覽圖像，但我得到一個錯誤。

這裏是我的.java：

package ianco.test.andrei; 
    import android.app.Activity; 
    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.View.OnClickListener; 
    import android.widget.Button; 

    public class BrowsePicture extends Activity { 

//YOU CAN EDIT THIS TO WHATEVER YOU WANT 
private static final int SELECT_PICTURE = 1; 

private String selectedImagePath; 
//ADDED 
private String filemanagerstring; 

public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 



    Button sButton = (Button) findViewById(R.id.button1); 
    sButton.setOnClickListener(new OnClickListener() { 

     public void onClick(View arg0) { 

      // in onCreate or any event where your want the user to 
      // select a file 
      Intent intent = new Intent(); 
      intent.setType("image/*"); 
      intent.setAction(Intent.ACTION_GET_CONTENT); 
      startActivityForResult(Intent.createChooser(intent, 
        "Select Picture"), SELECT_PICTURE); 
     } 
    }); 
} 

//UPDATED 
public void onActivityResult(int requestCode, int resultCode, Intent data) { 
    if (resultCode == RESULT_OK) { 
     if (requestCode == SELECT_PICTURE) { 
      Uri selectedImageUri = data.getData(); 

      //OI FILE Manager 
      filemanagerstring = selectedImageUri.getPath(); 

      //MEDIA GALLERY 
      selectedImagePath = getPath(selectedImageUri); 

      //DEBUG PURPOSE - you can delete this if you want 
      if(selectedImagePath!=null) 
       System.out.println(selectedImagePath); 
      else System.out.println("selectedImagePath is null"); 
      if(filemanagerstring!=null) 
       System.out.println(filemanagerstring); 
      else System.out.println("filemanagerstring is null"); 

      //NOW WE HAVE OUR WANTED STRING 
      if(selectedImagePath!=null) 
       System.out.println("selectedImagePath is the right one for you!"); 
      else 
       System.out.println("filemanagerstring is the right one for you!"); 
     } 
    } 
} 

//UPDATED! 
public String getPath(Uri uri) { 
    String[] projection = { MediaStore.Images.Media.DATA }; 
    Cursor cursor = managedQuery(uri, projection, null, null, null); 
    if(cursor!=null) 
    { 
     //HERE YOU WILL GET A NULLPOINTER IF CURSOR IS NULL 
     //THIS CAN BE, IF YOU USED OI FILE MANAGER FOR PICKING THE MEDIA 
     int column_index = cursor 
     .getColumnIndexOrThrow(MediaStore.Images.Media.DATA); 
     cursor.moveToFirst(); 
     return cursor.getString(column_index); 
    } 
    else return null; 
} 

}

錯誤是：12-24 00:14:07.742: E/AndroidRuntime(365): FATAL EXCEPTION: main 12-24 00:14:07.742: E/AndroidRuntime(365): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{ianco.test.andrei/ianco.test.andrei.TestareActivity}: java.lang.ClassNotFoundException: ianco.test.andrei.TestareActivity in loader dalvik.system.PathClassLoader[/data/app/ianco.test.andrei-1.apk] 12-24 00:14:07.742: E/AndroidRuntime(365): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2585) 12-24 00:14:07.742: E/AndroidRuntime(365): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679) 12-24 00:14:07.742: E/AndroidRuntime(365): at android.app.ActivityThread.access$2300(ActivityThread.java:125) 12-24 00:14:07.742: E/AndroidRuntime(365): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033) 12-24 00:14:07.742: E/AndroidRuntime(365): at android.os.Handler.dispatchMessage(Handler.java:99) 12-24 00:14:07.742: E/AndroidRuntime(365): at android.os.Looper.loop(Looper.java:123) 12-24 00:14:07.742: E/AndroidRuntime(365): at android.app.ActivityThread.main(ActivityThread.java:4627) 12-24 00:14:07.742: E/AndroidRuntime(365): at java.lang.reflect.Method.invokeNative(Native Method) 12-24 00:14:07.742: E/AndroidRuntime(365): at java.lang.reflect.Method.invoke(Method.java:521) 12-24 00:14:07.742: E/AndroidRuntime(365): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 12-24 00:14:07.742: E/AndroidRuntime(365): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 12-24 00:14:07.742: E/AndroidRuntime(365): at dalvik.system.NativeStart.main(Native Method) 12-24 00:14:07.742: E/AndroidRuntime(365): Caused by: java.lang.ClassNotFoundException: ianco.test.andrei.TestareActivity in loader dalvik.system.PathClassLoader[/data/app/ianco.test.andrei-1.apk] 12-24 00:14:07.742: E/AndroidRuntime(365): at dalvik.system.PathClassLoader.findClass(PathClassLoader.java:243) 12-24 00:14:07.742: E/AndroidRuntime(365): at java.lang.ClassLoader.loadClass(ClassLoader.java:573) 12-24 00:14:07.742: E/AndroidRuntime(365): at java.lang.ClassLoader.loadClass(ClassLoader.java:532) 12-24 00:14:07.742: E/AndroidRuntime(365): at android.app.Instrumentation.newActivity(Instrumentation.java:1021) 12-24 00:14:07.742: E/AndroidRuntime(365): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2577)

Answer 1

你的清單具有對一個TestareActivity的引用不存在：

00:14:07.742: E/AndroidRuntime(365): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{ianco.test.andrei/ianco.test.andrei.TestareActivity}: java.lang.ClassNotFoundException: ianco.test.andrei.TestareActivity in loader dalvik.system.PathClassLoader[/data/app/ianco.test.andrei-1.apk] 

修復清單或添加缺失的活動。