按钮上的“放大/缩小”图像在Android中单击？
我是Android的新手。我已经按照这个问题，我成功缩放图像这个代码工作正常可以有人请帮我如何编写按钮点击的zoomin zoomout代码。我没有得到如何实现这个任务
这是我遵循Tutorial Zoom Image的教程，也遵循“ Salman的Ayub答案 ”
它工作正常，但我无法在放大和缩小图像时应用比例因子
您需要将这两个方法添加到TouchImageView类：
public void zoomIn() { oldScale = saveScale; if(saveScale<=maxScale) { saveScale += .5; matrix.setScale(saveScale, saveScale); setImageMatrix(matrix); invalidate(); // Center the image // Center the image if(bmHeight>bmWidth) { redundantXSpace = width - (saveScale * bmWidth); redundantXSpace /= 2; } else { redundantYSpace = height - (saveScale * bmHeight) ; redundantYSpace /= 2; } matrix.postTranslate(redundantXSpace , redundantYSpace ); setImageMatrix(matrix); invalidate(); } } public void zoomOut() { if(saveScale>=minScale) { saveScale -= .5; matrix.setScale(saveScale, saveScale); setImageMatrix(matrix); invalidate(); // Center the image if(bmHeight>bmWidth) { redundantXSpace = width - (saveScale * bmWidth); redundantXSpace /= 2; } else { redundantYSpace = height - (saveScale * bmHeight) ; redundantYSpace /= 2; } matrix.postTranslate(redundantXSpace , redundantYSpace ); setImageMatrix(matrix); invalidate(); } }
这是完整的TouchImageView类代码，以及这两种方法：
public class TouchImageView extends ImageView { public Matrix matrix = new Matrix(); // We can be in one of these 3 states static final int NONE = 0; static final int DRAG = 1; static final int ZOOM = 2; static final int CLICK = 3; int mode = NONE; float oldScale = 1.0f; // Remember some things for zooming PointF last = new PointF(); PointF start = new PointF(); float minScale = 1f; float maxScale = 4f; float[] m; float redundantXSpace, redundantYSpace; float width, height; float saveScale = 1f; float right, bottom, origWidth, origHeight, bmWidth, bmHeight; ScaleGestureDetector mScaleDetector; Context context; public TouchImageView(Context context) { super(context); super.setClickable(true); this.context = context; mScaleDetector = new ScaleGestureDetector(context, new ScaleListener()); matrix.setTranslate(1f, 1f); m = new float[9]; setImageMatrix(matrix); setScaleType(ScaleType.MATRIX); setOnTouchListener(new OnTouchListener() { @Override public boolean onTouch(View v, MotionEvent event) { mScaleDetector.onTouchEvent(event); matrix.getValues(m); float x = m[Matrix.MTRANS_X]; float y = m[Matrix.MTRANS_Y]; PointF curr = new PointF(event.getX(), event.getY()); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: last.set(event.getX(), event.getY()); start.set(last); mode = DRAG; break; case MotionEvent.ACTION_POINTER_DOWN: last.set(event.getX(), event.getY()); start.set(last); mode = ZOOM; break; case MotionEvent.ACTION_MOVE: if (mode == ZOOM || (mode == DRAG && saveScale > minScale)) { Log.d("******", "ZOOM OR DRAG"); float deltaX = curr.x - last.x; float deltaY = curr.y - last.y; float scaleWidth = Math.round(origWidth * saveScale); float scaleHeight = Math.round(origHeight * saveScale); if (scaleWidth < width) { deltaX = 0; if (y + deltaY > 0) deltaY = -y; else if (y + deltaY < -bottom) deltaY = -(y + bottom); } else if (scaleHeight < height) { deltaY = 0; if (x + deltaX > 0) deltaX = -x; else if (x + deltaX < -right) deltaX = -(x + right); } else { if (x + deltaX > 0) deltaX = -x; else if (x + deltaX < -right) deltaX = -(x + right); if (y + deltaY > 0) deltaY = -y; else if (y + deltaY < -bottom) deltaY = -(y + bottom); } matrix.postTranslate(deltaX, deltaY); last.set(curr.x, curr.y); }else if(mode == DRAG && saveScale == minScale) { Log.d("******", "DRAG"); } break; case MotionEvent.ACTION_UP: mode = NONE; int xDiff = (int) Math.abs(curr.x - start.x); int yDiff = (int) Math.abs(curr.y - start.y); if (xDiff < CLICK && yDiff < CLICK) performClick(); break; case MotionEvent.ACTION_POINTER_UP: mode = NONE; break; } setImageMatrix(matrix); invalidate(); return true; // indicate event was handled } }); } @Override public void setImageBitmap(Bitmap bm) { super.setImageBitmap(bm); bmWidth = bm.getWidth(); bmHeight = bm.getHeight(); } public void setMaxZoom(float x) { maxScale = x; } private class ScaleListener extends ScaleGestureDetector.SimpleOnScaleGestureListener { @Override public boolean onScaleBegin(ScaleGestureDetector detector) { mode = ZOOM; return true; } @Override public boolean onScale(ScaleGestureDetector detector) { float mScaleFactor = detector.getScaleFactor();//(float)Math.min(Math.max(.95f, detector.getScaleFactor()), 1.05); float origScale = saveScale; saveScale *= mScaleFactor; if (saveScale > maxScale) { saveScale = maxScale; mScaleFactor = maxScale / origScale; } else if (saveScale < minScale) { saveScale = minScale; mScaleFactor = minScale / origScale; } right = width * saveScale - width - (2 * redundantXSpace * saveScale); bottom = height * saveScale - height - (2 * redundantYSpace * saveScale); if (origWidth * saveScale <= width || origHeight * saveScale <= height) { matrix.postScale(mScaleFactor, mScaleFactor, width / 2, height / 2); if (mScaleFactor < 1) { matrix.getValues(m); float x = m[Matrix.MTRANS_X]; float y = m[Matrix.MTRANS_Y]; if (mScaleFactor < 1) { if (Math.round(origWidth * saveScale) < width) { if (y < -bottom) matrix.postTranslate(0, -(y + bottom)); else if (y > 0) matrix.postTranslate(0, -y); } else { if (x < -right) matrix.postTranslate(-(x + right), 0); else if (x > 0) matrix.postTranslate(-x, 0); } } } } else { matrix.postScale(mScaleFactor, mScaleFactor, detector.getFocusX(), detector.getFocusY()); matrix.getValues(m); float x = m[Matrix.MTRANS_X]; float y = m[Matrix.MTRANS_Y]; if (mScaleFactor < 1) { if (x < -right) matrix.postTranslate(-(x + right), 0); else if (x > 0) matrix.postTranslate(-x, 0); if (y < -bottom) matrix.postTranslate(0, -(y + bottom)); else if (y > 0) matrix.postTranslate(0, -y); } } return true; } } @Override protected void onMeasure (int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); width = MeasureSpec.getSize(widthMeasureSpec); height = MeasureSpec.getSize(heightMeasureSpec); //Fit to screen. float scale; float scaleX = width / bmWidth; float scaleY = height / bmHeight; scale = Math.min(scaleX, scaleY); matrix.setScale(scale, scale); setImageMatrix(matrix); saveScale = 1f; // Center the image redundantYSpace = height - (scale * bmHeight) ; redundantXSpace = width - (scale * bmWidth); redundantYSpace /= 2; redundantXSpace /= 2; matrix.postTranslate(redundantXSpace, redundantYSpace); origWidth = width - 2 * redundantXSpace; origHeight = height - 2 * redundantYSpace; right = width * saveScale - width - (2 * redundantXSpace * saveScale); bottom = height * saveScale - height - (2 * redundantYSpace * saveScale); setImageMatrix(matrix); } public TouchImageView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); super.setClickable(true); this.context = context; mScaleDetector = new ScaleGestureDetector(context, new ScaleListener()); matrix.setTranslate(1f, 1f); m = new float[9]; setImageMatrix(matrix); setScaleType(ScaleType.MATRIX); setOnTouchListener(new OnTouchListener() { @Override public boolean onTouch(View v, MotionEvent event) { mScaleDetector.onTouchEvent(event); matrix.getValues(m); float x = m[Matrix.MTRANS_X]; float y = m[Matrix.MTRANS_Y]; PointF curr = new PointF(event.getX(), event.getY()); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: last.set(event.getX(), event.getY()); start.set(last); mode = DRAG; break; case MotionEvent.ACTION_POINTER_DOWN: last.set(event.getX(), event.getY()); start.set(last); mode = ZOOM; break; case MotionEvent.ACTION_MOVE: if (mode == ZOOM || (mode == DRAG && saveScale > minScale)) { Log.d("******", "ZOOM OR DRAG"); float deltaX = curr.x - last.x; float deltaY = curr.y - last.y; float scaleWidth = Math.round(origWidth * saveScale); float scaleHeight = Math.round(origHeight * saveScale); if (scaleWidth < width) { deltaX = 0; if (y + deltaY > 0) deltaY = -y; else if (y + deltaY < -bottom) deltaY = -(y + bottom); } else if (scaleHeight < height) { deltaY = 0; if (x + deltaX > 0) deltaX = -x; else if (x + deltaX < -right) deltaX = -(x + right); } else { if (x + deltaX > 0) deltaX = -x; else if (x + deltaX < -right) deltaX = -(x + right); if (y + deltaY > 0) deltaY = -y; else if (y + deltaY < -bottom) deltaY = -(y + bottom); } matrix.postTranslate(deltaX, deltaY); last.set(curr.x, curr.y); }else if(mode == DRAG && saveScale == minScale) { Log.d("******", "DRAG"); } break; case MotionEvent.ACTION_UP: mode = NONE; int xDiff = (int) Math.abs(curr.x - start.x); int yDiff = (int) Math.abs(curr.y - start.y); if (xDiff < CLICK && yDiff < CLICK) performClick(); break; case MotionEvent.ACTION_POINTER_UP: mode = NONE; break; } setImageMatrix(matrix); invalidate(); return true; // indicate event was handled } }); } public TouchImageView(Context context, AttributeSet attrs) { super(context, attrs); super.setClickable(true); this.context = context; mScaleDetector = new ScaleGestureDetector(context, new ScaleListener()); matrix.setTranslate(1f, 1f); m = new float[9]; setImageMatrix(matrix); setScaleType(ScaleType.MATRIX); setOnTouchListener(new OnTouchListener() { @Override public boolean onTouch(View v, MotionEvent event) { mScaleDetector.onTouchEvent(event); matrix.getValues(m); float x = m[Matrix.MTRANS_X]; float y = m[Matrix.MTRANS_Y]; PointF curr = new PointF(event.getX(), event.getY()); switch (event.getAction()) { case MotionEvent.ACTION_DOWN: last.set(event.getX(), event.getY()); start.set(last); mode = DRAG; break; case MotionEvent.ACTION_POINTER_DOWN: last.set(event.getX(), event.getY()); start.set(last); mode = ZOOM; break; case MotionEvent.ACTION_MOVE: if (mode == ZOOM || (mode == DRAG && saveScale > minScale)) { Log.d("******", "ZOOM OR DRAG"); float deltaX = curr.x - last.x; float deltaY = curr.y - last.y; float scaleWidth = Math.round(origWidth * saveScale); float scaleHeight = Math.round(origHeight * saveScale); if (scaleWidth < width) { deltaX = 0; if (y + deltaY > 0) deltaY = -y; else if (y + deltaY < -bottom) deltaY = -(y + bottom); } else if (scaleHeight < height) { deltaY = 0; if (x + deltaX > 0) deltaX = -x; else if (x + deltaX < -right) deltaX = -(x + right); } else { if (x + deltaX > 0) deltaX = -x; else if (x + deltaX < -right) deltaX = -(x + right); if (y + deltaY > 0) deltaY = -y; else if (y + deltaY < -bottom) deltaY = -(y + bottom); } matrix.postTranslate(deltaX, deltaY); last.set(curr.x, curr.y); }else if(mode == DRAG && saveScale == minScale) { Log.d("******", "DRAG"); } break; case MotionEvent.ACTION_UP: mode = NONE; int xDiff = (int) Math.abs(curr.x - start.x); int yDiff = (int) Math.abs(curr.y - start.y); if (xDiff < CLICK && yDiff < CLICK) performClick(); break; case MotionEvent.ACTION_POINTER_UP: mode = NONE; break; } setImageMatrix(matrix); invalidate(); return true; // indicate event was handled } }); } public void zoomIn() { oldScale = saveScale; if(saveScale<=maxScale) { saveScale += .5; matrix.setScale(saveScale, saveScale); setImageMatrix(matrix); invalidate(); // Center the image // Center the image if(bmHeight>bmWidth) { redundantXSpace = width - (saveScale * bmWidth); redundantXSpace /= 2; } else { redundantYSpace = height - (saveScale * bmHeight) ; redundantYSpace /= 2; } matrix.postTranslate(redundantXSpace , redundantYSpace ); setImageMatrix(matrix); invalidate(); } } public void zoomOut() { if(saveScale>=minScale) { saveScale -= .5; matrix.setScale(saveScale, saveScale); setImageMatrix(matrix); invalidate(); // Center the image if(bmHeight>bmWidth) { redundantXSpace = width - (saveScale * bmWidth); redundantXSpace /= 2; } else { redundantYSpace = height - (saveScale * bmHeight) ; redundantYSpace /= 2; } matrix.postTranslate(redundantXSpace , redundantYSpace ); setImageMatrix(matrix); invalidate(); } } }
在这里你可以在zoomIn / zoomOut按钮中使用它们：
protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.LAYOUT_NAME); Button zoonIn = (Button)findViewById(R.id.ZOOM_IN_BUTTON_ID); Button zoonOut = (Button)findViewById(R.id.ZOOM_OUT_BUTTON_ID); final TouchImageView touch = (TouchImageView)findViewById(R.id.YOUR_TOUCH_IMAGE_VIEW_)ID); Bitmap bImage = BitmapFactory.decodeResource(this.getResources(), R.drawable.DRAWABLE_ID); touch.setImageBitmap(bImage); touch.setMaxZoom(4f); //change the max level of zoom, default is 3f zoonIn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub touch.zoomIn(); } }); zoonOut.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { // TODO Auto-generated method stub touch.zoomOut(); } }); }
我希望这有帮助。
放大/缩小按钮图像的最简单方法是将其显示在webView中，然后您可以使用webView提供的所有function。
将您的图像复制到assets文件夹中，然后将其加载到onCreate中：
WebView mWebView = (WebView) findViewById(R.id.webView1); mWebView.setScrollBarStyle(WebView.SCROLLBARS_OUTSIDE_OVERLAY); mWebView.setBackgroundColor(Color.parseColor("#ffffff")); mWebView.loadUrl("file:///android_asset/image.png"); mWebView.getSettings().setBuiltInZoomControls(true); mWebView.setInitialScale(50);
尝试使用PhotoView 。 我认为它可以开箱即用。