如何将位图保存到内部存储

Question

如何将位图保存到内部存储

50

这是我的代码，我想将这个位图保存到内部存储器中。公共布尔值saveImageToInternalStorage是谷歌提供的代码，但我不知道如何使用它。当我触摸button2时，按照button1的操作执行。

public class MainActivity extends Activity implements OnClickListener {
Button btn, btn1;
SurfaceView sv;
Bitmap bitmap;
Canvas canvas;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    btn=(Button)findViewById(R.id.button1);
    btn1=(Button)findViewById(R.id.button2);
    sv=(SurfaceView)findViewById(R.id.surfaceView1);

    btn.setOnClickListener(this);
    btn1.setOnClickListener(this);

    bitmap=BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);

}
@Override
public void onClick(View v) {
    canvas=sv.getHolder().lockCanvas();
    if(canvas==null) return;
    canvas.drawBitmap(bitmap, 100, 100, null);
    sv.getHolder().unlockCanvasAndPost(canvas);


}

public boolean saveImageToInternalStorage(Bitmap image) {

    try {
    // Use the compress method on the Bitmap object to write image to
    // the OutputStream
    FileOutputStream fos = openFileOutput("desiredFilename.png", Context.MODE_PRIVATE);

    // Writing the bitmap to the output stream
    image.compress(Bitmap.CompressFormat.PNG, 100, fos);
    fos.close();

    return true;
    } catch (Exception e) {
    Log.e("saveToInternalStorage()", e.getMessage());
    return false;
    }
    }
 }

- Marius Hincu

5个回答

13

private static void SaveImage(Bitmap finalBitmap) {

    String root = Environment.getExternalStorageDirectory().getAbsolutePath();
    File myDir = new File(root + "/saved_images");
    myDir.mkdirs();

    String fname = "Image-"+ o +".jpg";
    File file = new File (myDir, fname);
    if (file.exists ()) file.delete ();
    try {
        FileOutputStream out = new FileOutputStream(file);
        finalBitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);
        out.flush();
        out.close();

    } catch (Exception e) {
        e.printStackTrace();
    }
}

- Gaby Bou Tayeh

1

将文件保存到目录中。

  public static Uri saveImageToInternalStorage(Context mContext, Bitmap bitmap){

    String mTimeStamp = new SimpleDateFormat("ddMMyyyy_HHmm").format(new Date());

    String mImageName = "snap_"+mTimeStamp+".jpg";

    ContextWrapper wrapper = new ContextWrapper(mContext);

    File file = wrapper.getDir("Images",MODE_PRIVATE);

    file = new File(file, "snap_"+ mImageName+".jpg");

    try{

        OutputStream stream = null;

        stream = new FileOutputStream(file);

        bitmap.compress(Bitmap.CompressFormat.JPEG,100,stream);

        stream.flush();

        stream.close();

    }catch (IOException e) 
    {
        e.printStackTrace();
    }

    Uri mImageUri = Uri.parse(file.getAbsolutePath());

    return mImageUri;
}

必需的权限

<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

- Mahesh Pandit

1

你可以使用以下方法对图像进行解码、压缩和保存：

     @Override
     public void onClick(View view) {
                onItemSelected1();
                InputStream image_stream = null;
                try {
                    image_stream = getContentResolver().openInputStream(myUri);
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                }

                Bitmap image= BitmapFactory.decodeStream(image_stream );
                // path to sd card
                File path=Environment.getExternalStorageDirectory();
                //create a file
                File  dir=new File(path+"/ComDec/");
                dir.mkdirs();
                Date date=new Date();
                File file=new File(dir,date+".jpg");

                OutputStream out=null;
                try{
                    out=new FileOutputStream(file);
                    image.compress(format,size,out);
                    out.flush();
                    out.close();


                    MediaStore.Images.Media.insertImage(getContentResolver(), image," yourTitle "," yourDescription");

                    image=null;


                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
                Toast.makeText(SecondActivity.this,"Image Save Successfully",Toast.LENGTH_LONG).show();
            }
        });

- Amar Nath Rawat

1

将onClick()修改如下：

@Override
public void onClick(View v) {
    if(v == btn) {
        canvas=sv.getHolder().lockCanvas();
        if(canvas!=null) {
            canvas.drawBitmap(bitmap, 100, 100, null);
            sv.getHolder().unlockCanvasAndPost(canvas);
        }
    } else if(v == btn1) {
        saveBitmapToInternalStorage(bitmap);
    }
}

有几种方法可以强制要求在尝试保存位图之前必须先按下btn，然后再按下btn1。

我建议您最初禁用btn1，并在单击btn时启用它，如下所示：

if(v == btn) {
    ...
    btn1.setEnabled(true);
}

- David Manpearl

如何正确处理 if(view == btn) 和 else if(view == btn1) 的视图显示？ - Marius Hincu

我编辑了"view" -> "v"。这两个if()语句确定了在onClick()函数中哪个按钮被按下。 - David Manpearl

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- vinothp · Accepted Answer

要将位图保存在SD卡中，请使用以下代码：

存储图片

private void storeImage(Bitmap image) {
    File pictureFile = getOutputMediaFile();
    if (pictureFile == null) {
        Log.d(TAG,
                "Error creating media file, check storage permissions: ");// e.getMessage());
        return;
    } 
    try {
        FileOutputStream fos = new FileOutputStream(pictureFile);
        image.compress(Bitmap.CompressFormat.PNG, 90, fos);
        fos.close();
    } catch (FileNotFoundException e) {
        Log.d(TAG, "File not found: " + e.getMessage());
    } catch (IOException e) {
        Log.d(TAG, "Error accessing file: " + e.getMessage());
    }  
}

获取图像存储路径

/** Create a File for saving an image or video */
private  File getOutputMediaFile(){
    // To be safe, you should check that the SDCard is mounted
    // using Environment.getExternalStorageState() before doing this. 
    File mediaStorageDir = new File(Environment.getExternalStorageDirectory()
            + "/Android/data/"
            + getApplicationContext().getPackageName()
            + "/Files"); 

    // This location works best if you want the created images to be shared
    // between applications and persist after your app has been uninstalled.

    // Create the storage directory if it does not exist
    if (! mediaStorageDir.exists()){
        if (! mediaStorageDir.mkdirs()){
            return null;
        }
    } 
    // Create a media file name
    String timeStamp = new SimpleDateFormat("ddMMyyyy_HHmm").format(new Date());
    File mediaFile;
        String mImageName="MI_"+ timeStamp +".jpg";
        mediaFile = new File(mediaStorageDir.getPath() + File.separator + mImageName);  
    return mediaFile;
}

编辑根据您的评论，我已经修改了 onclick 视图，现在按钮1和按钮2的功能将会分别执行。

public onClick(View v){

switch(v.getId()){
case R.id.button1:
//Your button 1 function
break;
case R.id. button2:
//Your button 2 function
break;
} 
}