Question

我有一个完美的PerformCrop方法。

我想把它转移到我的＆＃39; util＆＃39;所以我可以在其他活动中称呼它。这有一个复杂因素，它使用返回调用类的意图。我认为这不应该是问题，但也许我不对。

以下是我所尝试的以及我所看到的问题

我将performCrop（）剪切并粘贴到我的util类中。
我在'startActivityForResult（cropIntent，CROP_IMAGE）中遇到错误;＆＃39;它没有识别方法，所以我用“扩展活动”
当它运行时出现错误并且我不是100％确定为什么会捕获异常

＆＃39; java.lang.NullPointerException：尝试调用虚方法＆＃39; android.app.ActivityThread $ ApplicationThread android.app.ActivityThread.getApplicationThread（）＆＃39;在null对象上参考＆＃39;

以下是方法，即onActivityResult＆＃39;方法。谁能告诉我如何将performCrop（）移动到非Activity扩展类？

代码

public void performCrop(Uri picUri)
{
    final int CROP_IMAGE = 2;
        /*
* PERFORM CROP
* this must take into account he fact we may not have a crop method on phone, or the diff ways diff OS crop
 */
    //NEXUS 5 OS 5 is example of this branch
    // take care of exceptions
    try {
        // call the standard crop action intent (the user device may not
        // support it)

        Intent cropIntent = new Intent("com.android.camera.action.CROP");
        // indicate image type and Uri
        cropIntent.setDataAndType(picUri, "image/*");
        // set crop properties
        cropIntent.putExtra("crop", "true");
        // // indicate aspect of desired crop
        cropIntent.putExtra("aspectX", 1);
        cropIntent.putExtra("aspectY", 1);
        // // // indicate output X and Y

        // retrieve data on return
        cropIntent.putExtra("return-data", true);
        // start the activity - we handle returning in onActivityResult
        startActivityForResult(cropIntent, CROP_IMAGE);
    }
    // respond to users whose devices do not support the crop action
    catch (ActivityNotFoundException anfe)
    {
        Toast toast = Toast.makeText(this,"This device doesn't support the crop action! Exception: " + anfe.toString(),Toast.LENGTH_SHORT);
        toast.show();
    }
    catch (OutOfMemoryError e)
    {//NOT TESTED AS HW DOES NOT GO HERE
        System.out.println("out of memory");
    }
    catch (Exception e)
    { //NOT TESTED AS HW DOES NOT GO HERE
        Display display = this.getWindowManager().getDefaultDisplay();
        Point size = new Point();
        //display.getSize(size);
        int width = size.x;
        int height = size.y;
        Intent cropIntent = new Intent("com.android.camera.action.CROP");
        // indicate image type and Uri
        cropIntent.setDataAndType(picUri, "image/*");
        // set crop properties
        cropIntent.putExtra("crop", "true");
        // // indicate aspect of desired crop
        cropIntent.putExtra("aspectX", 2);
        cropIntent.putExtra("aspectY", 1);
        // // indicate output X and Y
        cropIntent.putExtra("outputX", width);
        cropIntent.putExtra("outputY", 200);
        // retrieve data on return
        cropIntent.putExtra("return-data", true);
        // start the activity - we handle returning in onActivityResult
        startActivityForResult(cropIntent, CROP_IMAGE);
    }
}

当相机意图返回成功结果时从Activity调用。请注意，裁剪意图也将重新调整为此方法。

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data)
{
    // TODO Auto-generated method stub
    if (resultCode==RESULT_OK )
    {
        if(requestCode == CAMERA_IMAGE) //reply from camera
        {
            toolbox.performCrop(uri); //crop the picture
        }

        if(requestCode == CROP_IMAGE) //reply from crop
        {
           /* Bitmap bmp = getBitmap(uri);
            imgView.setImageBitmap(bmp);*/
            Bundle extras = data.getExtras();
            if (extras != null) {
                Bitmap bmp = extras.getParcelable("data");
                imgViewProfilePic.setImageBitmap(bmp);
            }
        }

        if (requestCode == PICK_IMAGE_FROM_GALLERY) //reply from gallery
        {
            Uri selectedImage = data.getData();
            uri = data.getData();
            toolbox.performCrop(uri);
        }
    }
}

Answer 1

创建一个类名CropImage，将你的方法performCrop（）放入其中并从你想要的任何地方调用它，

                CropImage cropImage = new CropImage(this);
                cropImage.performCrop(uri);

CropImage claas看起来像，

public class CropImage {
Context context;

public CropImage(Context context) {
    this.context = context;
}

public void performCrop(Uri picUri)
{
    final int CROP_IMAGE = 2;
    /*
    * PERFORM CROP
    * this must take into account he fact we may not have a crop method on phone, or the diff ways diff OS crop
    */
    //NEXUS 5 OS 5 is example of this branch
    // take care of exceptions
    try {
        // call the standard crop action intent (the user device may not
        // support it)

        Intent cropIntent = new Intent("com.android.camera.action.CROP");
        // indicate image type and Uri
        cropIntent.setDataAndType(picUri, "image/*");
        // set crop properties
        cropIntent.putExtra("crop", "true");
        // // indicate aspect of desired crop
        cropIntent.putExtra("aspectX", 1);
        cropIntent.putExtra("aspectY", 1);
        // // // indicate output X and Y

        // retrieve data on return
        cropIntent.putExtra("return-data", true);
        // start the activity - we handle returning in onActivityResult
        ((Activity)context).startActivityForResult(cropIntent, CROP_IMAGE);
    }
    // respond to users whose devices do not support the crop action
    catch (ActivityNotFoundException anfe)
    {
        Toast toast = Toast.makeText(context,"This device doesn't support the crop action! Exception: " + anfe.toString(), Toast.LENGTH_SHORT);
        toast.show();
    }
    catch (OutOfMemoryError e)
    {//NOT TESTED AS HW DOES NOT GO HERE
        System.out.println("out of memory");
    }
    catch (Exception e)
    { //NOT TESTED AS HW DOES NOT GO HERE
        Display display = ((Activity)context).getWindowManager().getDefaultDisplay();
        Point size = new Point();
        //display.getSize(size);
        int width = size.x;
        int height = size.y;
        Intent cropIntent = new Intent("com.android.camera.action.CROP");
        // indicate image type and Uri
        cropIntent.setDataAndType(picUri, "image/*");
        // set crop properties
        cropIntent.putExtra("crop", "true");
        // // indicate aspect of desired crop
        cropIntent.putExtra("aspectX", 2);
        cropIntent.putExtra("aspectY", 1);
        // // indicate output X and Y
        cropIntent.putExtra("outputX", width);
        cropIntent.putExtra("outputY", 200);
        // retrieve data on return
        cropIntent.putExtra("return-data", true);
        // start the activity - we handle returning in onActivityResult
        ((Activity)context).startActivityForResult(cropIntent, CROP_IMAGE);
    }
}
}

Answer 2

首先检查哪里结果

ifgetpaternt==null)
{
Startactivityforreslt(your intent,code);
}
else
{
getpaprent().Startactivityforreslt(your intent,code);
}

如果Getpaprent（）方法调用则结果发送到父活动。所以得到父活动的结果并重新发送到你的活动.....

重构活动类

2 个答案:

首先检查哪里结果