android - 如何剪切图像的某些部分并在imageview中显示它

时间:2012-10-11 10:29:13

标签: android imageview scale

我想在imageview中只显示图像的某些部分。见下图。 image part

在google + app中可以找到相同的示例,其中您可以看到包含图片的所有帖子。

任何链接,代码都会有所帮助。 感谢

3 个答案:

答案 0 :(得分:7)

// Set some constants
private static final Bitmap SOURCE_BITMAP = BitmapFactory.decodeFile(....); // Get the source Bitmap using your favorite method :-)
private static final int START_X = 10;
private static final int START_Y = 15;
private static final int WIDTH_PX = 100;
private static final int HEIGHT_PX = 100;

// Crop bitmap
Bitmap newBitmap = Bitmap.createBitmap(SOURCE_BITMAP, START_X, START_Y, WIDTH_PX, HEIGHT_PX, null, false);

// Assign new bitmap to ImageView
ImageView image = (ImageView)findViewById(R.id.image_view);
image.setImageBitmap(newBitmap);

答案 1 :(得分:4)

使用此代码

int width = bitmapOrg.width();
int height = bitmapOrg.height();
int newWidth = 200;
int newHeight = 200;

// calculate the scale - in this case = 0.4f
float scaleWidth = ((float) newWidth) / width;
float scaleHeight = ((float) newHeight) / height;

// createa matrix for the manipulation
Matrix matrix = new Matrix();
// resize the bit map
matrix.postScale(scaleWidth, scaleHeight);

// recreate the new Bitmap
Bitmap resizedBitmap = Bitmap.createBitmap(bitmapOrg, 0, 0, 
                  width, height, matrix, true); 

// make a Drawable from Bitmap to allow to set the BitMap 
// to the ImageView, ImageButton or what ever
BitmapDrawable bmd = new BitmapDrawable(resizedBitmap);

ImageView imageView = new ImageView(this);

// set the Drawable on the ImageView
imageView.setImageDrawable(bmd);

答案 2 :(得分:0)

如果有人想要从底部剪切图像

// recreate the new Bitmap
Bitmap resizedBitmap = Bitmap.createBitmap(bitmapOrg, x, y, 
                  width, height, matrix, true); 

用这个逻辑替换以下参数

y:(bitmapOrg.getHeight() - 1) - (问题中出现红框的高度)

身高:(问题中出现的红色框的高度)

通过这种方式,您可以避免例外情况(例如,x需要相应修改)

IllegalArgumentException: x + width must be <= bitmap.width() in android

IllegalArgumentException: y + width must be <= bitmap.height() in android