从本地图库获取图片

隐式启动activity

private static final String IMAGE_TYPE = "image/*";
private static final int RESULT_IMAGE = 10;

    //从本地图库获取图片
private void getAnotherPicFromMediaStore() {
        //本地图库
        /** Intent.ACTION_PICK **
         * Activity Action: Pick an item from the data, returning what was selected.
         * Input: {@link #getData} is URI containing a directory of data
         * (vnd.android.cursor.dir/*) from which to pick an item.
         * Output: The URI of the item that was picked.
         */
    Intent intent = new Intent(Intent.ACTION_PICK, null);
        //MediaStore.Images.Media.EXTERNAL_CONTENT_URI是照片的路径
    intent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI, IMAGE_TYPE);

    startActivityForResult(intent, RESULT_IMAGE);
    }

选完图片回调onActivityResult

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (resultCode != RESULT_OK) {
        return;
    }
    Intent intent = new Intent(this, PuzzleActivity.class);
    switch (requestCode) {
        case RESULT_IMAGE:
                //返回图片的Uri,此例中imageUri.toString = "content://media/external/images/media/38";
            Uri imageUri = data.getData();
                //通过contentResolver获取图片的路径
//↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓
            String[] filePathColumn = {MediaStore.Images.Media.DATA};
            Cursor cursor = getContentResolver().query(imageUri, filePathColumn, null, null, null);
//↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑
            if (!cursor.moveToFirst()) {
                return;
            }
//↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓↓
            int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
            String imagePath = cursor.getString(columnIndex);
//↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑↑
                //别忘了释放游标
            cursor.close();
            File imageFile = new File(imagePath);
            if (!imageFile.exists()) {
                return;
            }
            //do Something, imageFile就是选择的图片
            break;
    }
}

调用系统相机拍照片

隐式启动activity

//这个路径用来存放拍摄的照片
public static final String TEMP_IMAGE_PATH;
//拍照的返回码
public static final int RESULT_CAMERA = 20;

//直接照一张图片
private void getAnotherPicFromCamera() {
        //路径随便填,用来存储系统相机拍摄的照片,注意外部存储的权限
    TEMP_IMAGE_PATH = getApplication().getCacheDir().toString() + "/temp.png";
        //把路径转化为Uri
    Uri photoUri = Uri.fromFile(new File(TEMP_IMAGE_PATH));
        //使用系统相机的action
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
        //将Uri附加进intent传递过去
    intent.putExtra(MediaStore.EXTRA_OUTPUT, photoUri);
    startActivityForResult(intent, RESULT_CAMERA);
}

回调onActivityResult

@Override
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);
    if (resultCode != RESULT_OK) {
        return;
    }
    Intent intent = new Intent(this, PuzzleActivity.class);
    switch (requestCode) {
        case RESULT_CAMERA:
            //返回RESULT_OK,就说明TEMP_IMAGE_PATH这个成员变量表示的文件就是我们系统相机拍摄的图片
            File image = new File(TEMP_IMAGE_PATH);
            break;
    }
}