Android 如何将图库图像添加到绘图应用程序中

Question

我正在创建一个应用程序，人们可以在其中绘制草图并将其保存到图库中。我已经完成并且工作正常。我希望能够做的是从图库中获取图像并能够在其上进行绘制。我已经能够调出画廊来选择图像，但我无法弄清楚如何将该图像嵌入到 Canvas 上然后在 Canvas 上绘制

这是我的画廊按钮代码:

else if(view.getId()==R.id.GalleryButton){
            //new button
            AlertDialog.Builder newDialog = new AlertDialog.Builder(this);
            newDialog.setTitle("New drawing");
            newDialog.setMessage("Start new drawing (you will lose the current drawing)?");
            newDialog.setPositiveButton("Yes", new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int which){
                    Intent choosePictureIntent = new Intent(
                            Intent.ACTION_PICK,
                            android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                    startActivityForResult(choosePictureIntent, 0);


                }

            });
            newDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener(){
                public void onClick(DialogInterface dialog, int which){
                    dialog.cancel();
                }
            });
            newDialog.show();
        }

我确定在 startActivityForResult 部分之后必须有一些东西，而那是我无法解决的问题。我想嵌入图像的地方是 (R.id.drawing)。

编辑:

完整代码如下:

public class MainActivity extends Activity implements OnClickListener {

//custom drawing view
private DrawingView drawView;
//buttons
private ImageButton currPaint, drawBtn, eraseBtn, newBtn, saveBtn, galleryBtn, cameraBtn;
//sizes
private float smallBrush, mediumBrush, largeBrush;

Bitmap bitmap;

protected static final int CAMERA_PIC_REQUEST = 0;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    //get drawing view
    drawView = (DrawingView)findViewById(R.id.drawing);

    //get the palette and first color button
    LinearLayout paintLayout = (LinearLayout)findViewById(R.id.paint_colors);
    currPaint = (ImageButton)paintLayout.getChildAt(0);
    currPaint.setImageDrawable(getResources().getDrawable(R.drawable.paint_pressed));

    //sizes from dimensions
    smallBrush = getResources().getInteger(R.integer.small_size);
    mediumBrush = getResources().getInteger(R.integer.medium_size);
    largeBrush = getResources().getInteger(R.integer.large_size);

    //draw button
    drawBtn = (ImageButton)findViewById(R.id.draw_btn);
    drawBtn.setOnClickListener(this);

    //set initial size
    drawView.setBrushSize(mediumBrush);

    //erase button
    eraseBtn = (ImageButton)findViewById(R.id.erase_btn);
    eraseBtn.setOnClickListener(this);

    //new button
    newBtn = (ImageButton)findViewById(R.id.new_btn);
    newBtn.setOnClickListener(this);

    //save button
    saveBtn = (ImageButton)findViewById(R.id.save_btn);
    saveBtn.setOnClickListener(this);

    //new button
    galleryBtn = (ImageButton)findViewById(R.id.GalleryButton);
    galleryBtn.setOnClickListener(this);

    //new button
    cameraBtn = (ImageButton)findViewById(R.id.camera_btn);
    cameraBtn.setOnClickListener(this);
}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}

//user clicked paint
public void paintClicked(View view){
    //use chosen color

    //set erase false
    drawView.setErase(false);
    drawView.setBrushSize(drawView.getLastBrushSize());

    if(view!=currPaint){
        ImageButton imgView = (ImageButton)view;
        String color = view.getTag().toString();
        drawView.setColor(color);
        //update ui
        imgView.setImageDrawable(getResources().getDrawable(R.drawable.paint_pressed));
        currPaint.setImageDrawable(getResources().getDrawable(R.drawable.paint));
        currPaint=(ImageButton)view;
    }
}

@Override
public void onClick(View view){

    if(view.getId()==R.id.draw_btn){
        //draw button clicked
        final Dialog brushDialog = new Dialog(this);
        brushDialog.setTitle("Brush size:");
        brushDialog.setContentView(R.layout.brush_chooser);
        //listen for clicks on size buttons
        ImageButton smallBtn = (ImageButton)brushDialog.findViewById(R.id.small_brush);
        smallBtn.setOnClickListener(new OnClickListener(){
            @Override
            public void onClick(View v) {
                drawView.setErase(false);
                drawView.setBrushSize(smallBrush);
                drawView.setLastBrushSize(smallBrush);
                brushDialog.dismiss();
            }
        });
        ImageButton mediumBtn = (ImageButton)brushDialog.findViewById(R.id.medium_brush);
        mediumBtn.setOnClickListener(new OnClickListener(){
            @Override
            public void onClick(View v) {
                drawView.setErase(false);
                drawView.setBrushSize(mediumBrush);
                drawView.setLastBrushSize(mediumBrush);
                brushDialog.dismiss();
            }
        });
        ImageButton largeBtn = (ImageButton)brushDialog.findViewById(R.id.large_brush);
        largeBtn.setOnClickListener(new OnClickListener(){
            @Override
            public void onClick(View v) {
                drawView.setErase(false);
                drawView.setBrushSize(largeBrush);
                drawView.setLastBrushSize(largeBrush);
                brushDialog.dismiss();
            }
        });
        //show and wait for user interaction
        brushDialog.show();
    }
    else if(view.getId()==R.id.erase_btn){
        //switch to erase - choose size
        final Dialog brushDialog = new Dialog(this);
        brushDialog.setTitle("Eraser size:");
        brushDialog.setContentView(R.layout.brush_chooser);
        //size buttons
        ImageButton smallBtn = (ImageButton)brushDialog.findViewById(R.id.small_brush);
        smallBtn.setOnClickListener(new OnClickListener(){
            @Override
            public void onClick(View v) {
                drawView.setErase(true);
                drawView.setBrushSize(smallBrush);
                brushDialog.dismiss();
            }
        });
        ImageButton mediumBtn = (ImageButton)brushDialog.findViewById(R.id.medium_brush);
        mediumBtn.setOnClickListener(new OnClickListener(){
            @Override
            public void onClick(View v) {
                drawView.setErase(true);
                drawView.setBrushSize(mediumBrush);
                brushDialog.dismiss();
            }
        });
        ImageButton largeBtn = (ImageButton)brushDialog.findViewById(R.id.large_brush);
        largeBtn.setOnClickListener(new OnClickListener(){
            @Override
            public void onClick(View v) {
                drawView.setErase(true);
                drawView.setBrushSize(largeBrush);
                brushDialog.dismiss();
            }
        });
        brushDialog.show();
    }
    else if(view.getId()==R.id.new_btn){
        //new button
        AlertDialog.Builder newDialog = new AlertDialog.Builder(this);
        newDialog.setTitle("New drawing");
        newDialog.setMessage("Start new drawing (you will lose the current drawing)?");
        newDialog.setPositiveButton("Yes", new DialogInterface.OnClickListener(){
            public void onClick(DialogInterface dialog, int which){
                drawView.startNew();
                dialog.dismiss();
            }
        });
        newDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener(){
            public void onClick(DialogInterface dialog, int which){
                dialog.cancel();
            }
        });
        newDialog.show();
    }
    else if(view.getId()==R.id.save_btn){
        //save drawing
        AlertDialog.Builder saveDialog = new AlertDialog.Builder(this);
        saveDialog.setTitle("Save drawing");
        saveDialog.setMessage("Save drawing to device Gallery?");
        saveDialog.setPositiveButton("Yes", new DialogInterface.OnClickListener(){
            public void onClick(DialogInterface dialog, int which){
                //save drawing
                drawView.setDrawingCacheEnabled(true);
                //attempt to save
                String imgSaved = MediaStore.Images.Media.insertImage(
                        getContentResolver(), drawView.getDrawingCache(),
                        UUID.randomUUID().toString()+".png", "drawing");
                //feedback
                if(imgSaved!=null){
                    Toast savedToast = Toast.makeText(getApplicationContext(), 
                            "Drawing saved to Gallery!", Toast.LENGTH_SHORT);
                    savedToast.show();
                }
                else{
                    Toast unsavedToast = Toast.makeText(getApplicationContext(), 
                            "Oops! Image could not be saved.", Toast.LENGTH_SHORT);
                    unsavedToast.show();
                }
                drawView.destroyDrawingCache();
            }
        });
        saveDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener(){
            public void onClick(DialogInterface dialog, int which){
                dialog.cancel();
            }
        });
        saveDialog.show();
    }
    else if(view.getId()==R.id.GalleryButton){
        //new button
        AlertDialog.Builder newDialog = new AlertDialog.Builder(this);
        newDialog.setTitle("New drawing");
        newDialog.setMessage("Start new drawing (you will lose the current drawing)?");
        newDialog.setPositiveButton("Yes", new DialogInterface.OnClickListener(){
            public void onClick(DialogInterface dialog, int which){
                Intent choosePictureIntent = new Intent(
                        Intent.ACTION_PICK,
                        android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
                startActivityForResult(choosePictureIntent, 101);


            }

        });
        newDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener(){
            public void onClick(DialogInterface dialog, int which){
                dialog.cancel();
            }
        });
        newDialog.show();
    }

    else if(view.getId()==R.id.camera_btn){
        //new button
        AlertDialog.Builder newDialog = new AlertDialog.Builder(this);
        newDialog.setTitle("New drawing");
        newDialog.setMessage("Start new drawing (you will lose the current drawing)?");
        newDialog.setPositiveButton("Yes", new DialogInterface.OnClickListener(){
            public void onClick(DialogInterface dialog, int which){
                Intent intent = new Intent(getApplicationContext(), ChoosePicture.class); 
                intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP); 
                startActivity(intent);


            }

        });
        newDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener(){
            public void onClick(DialogInterface dialog, int which){
                dialog.cancel();
            }
        });
        newDialog.show();
}

@Override
                    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
                        InputStream stream = null;
                        if (requestCode == 101&& resultCode == Activity.RESULT_OK)
                        {
                            try 
                            {
                                // We need to recycle unused bitmaps
                                if (bitmap != null) 
                                {
                                    bitmap.recycle();
                                }
                                stream = getContentResolver().openInputStream(data.getData());
                                bitmap = BitmapFactory.decodeStream(stream);
                                ImageView imageView=(ImageView)findViewById(R.id.drawing);
                                imageView.setImageBitmap(bitmap);
                                imageView.getLayoutParams().height = bitmap.getHeight()/8;
                            }
                            catch (FileNotFoundException e)
                            {
                                e.printStackTrace();
                            }
                            if (stream != null)
                            {
                                try
                                {
                                    stream.close();
                                }
                                catch (IOException e)
                                {
                                    e.printStackTrace();
                                }
                            }
                        }
                    }
                };
}

RAGHUNANDAN 代码:

else if(view.getId()==R.id.GalleryButton){
            //new button
            AlertDialog.Builder newDialog = new AlertDialog.Builder(this);
            newDialog.setTitle("New drawing");
            newDialog.setMessage("Start new drawing (you will lose the current drawing)?");
            newDialog.setPositiveButton("Yes", new DialogInterface.OnClickListener(){
                public void  setDrawingThemefrmGallery()
                {
                    // To open up a gallery browser
                    Intent intent = new Intent();
                    intent.setType("image/*");
                    intent.setAction(Intent.ACTION_GET_CONTENT);
                    startActivityForResult(Intent.createChooser(intent, "Select Picture"),1);
                    // To handle when an image is selected from the browser, add the following to your Activity
                }

                public void onActivityResult(int requestCode, int resultCode, Intent data) {
                if (resultCode == RESULT_OK) {
                if (requestCode == 1) {
                Uri currImageURI = data.getData();
                String s= getRealPathFromURI(currImageURI);
                File file = new File(s);

                if (file.exists()) {
                Drawable d = Drawable.createFromPath(file.getAbsolutePath());
                drawView.setBackground(d);
                }
                else
                {
                       // file does not exist
                }

                }
                }
                }
                /**
                 * @param contentURI
                 * @return
                 */
                private String getRealPathFromURI(Uri contentURI) {
                    Cursor cursor = getContentResolver().query(contentURI, null, null, null, null);
                    if (cursor == null) { // Source is Dropbox or other similar local file path
                        return contentURI.getPath();
                    } else { 
                        cursor.moveToFirst(); 
                        int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA); 
                        return cursor.getString(idx); 
                    }
                }

非常感谢您。

Answer 1

试试下面的方法。

此外，如果图像太大而不适合您在将其设置为背景之前可能必须按比例缩小。根据需要使用适当的 BitmapFactory.decode 方法。

public void  setDrawingThemefrmGallery()
{
    // To open up a gallery browser
    Intent intent = new Intent();
    intent.setType("image/*");
    intent.setAction(Intent.ACTION_GET_CONTENT);
    startActivityForResult(Intent.createChooser(intent, "Select Picture"),1);
    // To handle when an image is selected from the browser, add the following to your Activity
}

@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (resultCode == RESULT_OK) {
if (requestCode == 1) {
Uri currImageURI = data.getData();
String s= getRealPathFromURI(currImageURI);
File file = new File(s);

if (file.exists()) {
Drawable d = Drawable.createFromPath(file.getAbsolutePath());
drawView.setBackground(d);
}
else
{
       // file does not exist
}

}
}
}
/**
 * @param contentURI
 * @return
 */
private String getRealPathFromURI(Uri contentURI) {
    Cursor cursor = getContentResolver().query(contentURI, null, null, null, null);
    if (cursor == null) { // Source is Dropbox or other similar local file path
        return contentURI.getPath();
    } else { 
        cursor.moveToFirst(); 
        int idx = cursor.getColumnIndex(MediaStore.Images.ImageColumns.DATA); 
        return cursor.getString(idx); 
    }
}

快照

从作为绘图 View 背景的图库中选取的图像，您可以在其上绘图。