Android设置位图图片

Question

我现在正在做一个绘画应用，请问如何加载图片并设置为Bitmap？

我已经设置了编码如下，并且链接了Class A和Class DrawView。

问题:

代码在 DrawView Class 中报告错误“The method setImageBitmap(Bitmap) is undefined for the type Bitmap” for the line

bitmap.setImageBitmap(BitmapFactory.decodeFile(picturePath));

，我不知道如何将图片加载到Bitmap。

A 类:

private DrawView drawView;
...
...

public void go_load_pic() 
{       
    Intent i = new Intent(Intent.ACTION_PICK,android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);                
    startActivityForResult(i, RESULT_LOAD_IMAGE);   
}   

protected void onActivityResult(int requestCode, int resultCode, Intent data) 
{
    super.onActivityResult(requestCode, resultCode, data);

    if (requestCode == RESULT_LOAD_IMAGE && resultCode == RESULT_OK && null != data) 
    {
        Uri selectedImage = data.getData();
        String[] filePathColumn = { MediaStore.Images.Media.DATA };

        Cursor cursor = getContentResolver().query(selectedImage, filePathColumn, null, null, null);
        cursor.moveToFirst();

        int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
        String picturePath = cursor.getString(columnIndex);
        cursor.close();

        drawView.load_pic(picturePath);     
    }   
}   

在 DrawView 类中:

public class DrawView extends View  // the main screen that is painted
{
   // used to determine whether user moved a finger enough to draw again   
   private static final float TOUCH_TOLERANCE = 10;

   private Bitmap bitmap; // drawing area for display or saving
   private Canvas bitmapCanvas; // used to draw on bitmap
   private Paint paintScreen; // use to draw bitmap onto screen
   private Paint paintLine; // used to draw lines onto bitmap
   private HashMap<Integer, Path> pathMap; // current Paths being drawn
   private HashMap<Integer, Point> previousPointMap; // current Points
   ...

public void load_pic(String picturePath) // load a picture from gallery
   {
      bitmap.setImageBitmap(BitmapFactory.decodeFile(picturePath)); //ERROR LINE
      invalidate(); // refresh the screen
   }

Answer 1

您正在调用 Bitmap 类中不存在的方法。该方法可在 ImageView 和 ImageButton 等框架小部件上找到。 BitmapFactory 已经返回一个 Bitmap，因此只需分配实例即可。

bitmap = BitmapFactory.decodeFile(picturePath);