Question

我正在研究android中的联系人列表项目，我想制作一个浏览按钮来浏览图像并将其保存在我的数据库中，以便每个联系人。然后我想在屏幕上显示图像。你能给我一个很好的例子或教程，如何浏览图像并保存/从数据库中检索？

首先，我试图让程序浏览图像，但我收到错误。

这是我的.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;
}

}

错误是：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

您的清单引用了不存在的TestareActivity：

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]

修复清单或添加缺少的活动。

android浏览图片

1 个答案: