小开

最佳答案

我使用WebView和加载图像从内存通过

webview.loadUrl("file://...")

WebView处理所有的平移、缩放和滚动。如果你使用wrap_content, webview不会比图像大，也不会显示白色区域。 WebView是更好的ImageView;)

小开

我改编了一些代码来创建一个支持多点触摸的TouchImageView(>2.1)。它的灵感来自于书你好,安卓系统!(第3版)

它包含在以下3个文件中 TouchImageView.java WrapMotionEvent.java EclairMotionEvent.java < / p >

TouchImageView.java

import se.robertfoss.ChanImageBrowser.Viewer;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.util.FloatMath;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.ImageView;


public class TouchImageView extends ImageView {


private static final String TAG = "Touch";
// These matrices will be used to move and zoom image
Matrix matrix = new Matrix();
Matrix savedMatrix = 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;
int mode = NONE;


// Remember some things for zooming
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;


Context context;




public TouchImageView(Context context) {
super(context);
super.setClickable(true);
this.context = context;


matrix.setTranslate(1f, 1f);
setImageMatrix(matrix);
setScaleType(ScaleType.MATRIX);


setOnTouchListener(new OnTouchListener() {


@Override
public boolean onTouch(View v, MotionEvent rawEvent) {
WrapMotionEvent event = WrapMotionEvent.wrap(rawEvent);


// Dump touch event to log
if (Viewer.isDebug == true){
dumpEvent(event);
}


// Handle touch events here...
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
Log.d(TAG, "mode=DRAG");
mode = DRAG;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
Log.d(TAG, "oldDist=" + oldDist);
if (oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
Log.d(TAG, "mode=ZOOM");
}
break;
case MotionEvent.ACTION_UP:
int xDiff = (int) Math.abs(event.getX() - start.x);
int yDiff = (int) Math.abs(event.getY() - start.y);
if (xDiff < 8 && yDiff < 8){
performClick();
}
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
Log.d(TAG, "mode=NONE");
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
// ...
matrix.set(savedMatrix);
matrix.postTranslate(event.getX() - start.x, event.getY() - start.y);
} else if (mode == ZOOM) {
float newDist = spacing(event);
Log.d(TAG, "newDist=" + newDist);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist / oldDist;
matrix.postScale(scale, scale, mid.x, mid.y);
}
}
break;
}


setImageMatrix(matrix);
return true; // indicate event was handled
}


});
}




public void setImage(Bitmap bm, int displayWidth, int displayHeight) {
super.setImageBitmap(bm);


//Fit to screen.
float scale;
if ((displayHeight / bm.getHeight()) >= (displayWidth / bm.getWidth())){
scale =  (float)displayWidth / (float)bm.getWidth();
} else {
scale = (float)displayHeight / (float)bm.getHeight();
}


savedMatrix.set(matrix);
matrix.set(savedMatrix);
matrix.postScale(scale, scale, mid.x, mid.y);
setImageMatrix(matrix);




// Center the image
float redundantYSpace = (float)displayHeight - (scale * (float)bm.getHeight()) ;
float redundantXSpace = (float)displayWidth - (scale * (float)bm.getWidth());


redundantYSpace /= (float)2;
redundantXSpace /= (float)2;




savedMatrix.set(matrix);
matrix.set(savedMatrix);
matrix.postTranslate(redundantXSpace, redundantYSpace);
setImageMatrix(matrix);
}




/** Show an event in the LogCat view, for debugging */
private void dumpEvent(WrapMotionEvent event) {
// ...
String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE",
"POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" };
StringBuilder sb = new StringBuilder();
int action = event.getAction();
int actionCode = action & MotionEvent.ACTION_MASK;
sb.append("event ACTION_").append(names[actionCode]);
if (actionCode == MotionEvent.ACTION_POINTER_DOWN
|| actionCode == MotionEvent.ACTION_POINTER_UP) {
sb.append("(pid ").append(
action >> MotionEvent.ACTION_POINTER_ID_SHIFT);
sb.append(")");
}
sb.append("[");
for (int i = 0; i < event.getPointerCount(); i++) {
sb.append("#").append(i);
sb.append("(pid ").append(event.getPointerId(i));
sb.append(")=").append((int) event.getX(i));
sb.append(",").append((int) event.getY(i));
if (i + 1 < event.getPointerCount())
sb.append(";");
}
sb.append("]");
Log.d(TAG, sb.toString());
}


/** Determine the space between the first two fingers */
private float spacing(WrapMotionEvent event) {
// ...
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return FloatMath.sqrt(x * x + y * y);
}


/** Calculate the mid point of the first two fingers */
private void midPoint(PointF point, WrapMotionEvent event) {
// ...
float x = event.getX(0) + event.getX(1);
float y = event.getY(0) + event.getY(1);
point.set(x / 2, y / 2);
}
}

WrapMotionEvent.java

import android.view.MotionEvent;


public class WrapMotionEvent {
protected MotionEvent event;








protected WrapMotionEvent(MotionEvent event) {
this.event = event;
}


static public WrapMotionEvent wrap(MotionEvent event) {
try {
return new EclairMotionEvent(event);
} catch (VerifyError e) {
return new WrapMotionEvent(event);
}
}






public int getAction() {
return event.getAction();
}


public float getX() {
return event.getX();
}


public float getX(int pointerIndex) {
verifyPointerIndex(pointerIndex);
return getX();
}


public float getY() {
return event.getY();
}


public float getY(int pointerIndex) {
verifyPointerIndex(pointerIndex);
return getY();
}


public int getPointerCount() {
return 1;
}


public int getPointerId(int pointerIndex) {
verifyPointerIndex(pointerIndex);
return 0;
}


private void verifyPointerIndex(int pointerIndex) {
if (pointerIndex > 0) {
throw new IllegalArgumentException(
"Invalid pointer index for Donut/Cupcake");
}
}


}

EclairMotionEvent.java

import android.view.MotionEvent;


public class EclairMotionEvent extends WrapMotionEvent {


protected EclairMotionEvent(MotionEvent event) {
super(event);
}


public float getX(int pointerIndex) {
return event.getX(pointerIndex);
}


public float getY(int pointerIndex) {
return event.getY(pointerIndex);
}


public int getPointerCount() {
return event.getPointerCount();
}


public int getPointerId(int pointerIndex) {
return event.getPointerId(pointerIndex);
}
}

小开

你也可以尝试http://code.google.com/p/android-multitouch-controller/

这个图书馆真的很棒，尽管一开始有点难以理解。

小开

更新

我刚刚给TouchImageView一个新的更新。它现在包括双击缩放和抛除平移和捏缩放。下面的代码是非常日期。你可以检查github项目以获得最新的代码。

使用

将TouchImageView.java放到你的项目中。这样就可以像 ImageView。例子:< / p >

TouchImageView img = (TouchImageView) findViewById(R.id.img);

如果你在xml中使用TouchImageView，那么你必须提供完整的包名称，因为它是一个自定义视图。例子:< / p >

<com.example.touch.TouchImageView
android:id="@+id/img”
android:layout_width="match_parent"
android:layout_height="match_parent" />

注意:我已经删除了我之前的答案，其中包括一些非常旧的代码，现在直接链接到github上最新的代码。

: viewpage

如果你对将TouchImageView放入ViewPager感兴趣，参考这个答案。

小开

你可以尝试使用LayoutParams

public void zoom(boolean flag){
if(flag){
int width=40;
int height=40;
}
else{
int width=20;
int height=20;
}
RelativeLayout.LayoutParams param=new RelativeLayout.LayoutParams(width,height); //use the parent layout of the ImageView;
imageView.setLayoutParams(param); //imageView is the view which needs zooming.
}

ZoomIn =缩放(true); ZoomOut =缩放(false);

小开

@Robert Foss， @Mike Ortiz，非常感谢你们的工作。我合并了你的工作，并完成了罗伯特的android> 2.0课程与迈克的额外工作。

由于我的工作，我提出了Android触摸画廊，基于ViewPager和使用修改的TouchImageView。图片通过URL加载，你可以缩放和拖动它们。你可以在这里找到它https://github.com/Dreddik/AndroidTouchGallery

小开

在回答Janusz最初的问题时，有几种方法可以实现这一目标，这些方法的难度各不相同，如下所述。使用web视图很好，但在观感和可控性方面非常有限。如果你在画布上绘制位图，最通用的解决方案似乎是MikeOrtiz, Robert Foss和/或Jacob Nordfalk的建议。这里有一个通过PaulBourke来合并android-multitouch controller的很好的例子，并且对于拥有多点触摸支持和所有类型的自定义视图是很好的。

就我个人而言，如果你只是简单地绘制一个画布到一个位图，然后在ImageView中显示它，并希望能够使用多点触摸缩放和移动，我发现MikeOrtiz的解决方案是最简单的。然而，出于我的目的，他提供的Git代码似乎只在他的TouchImageView自定义ImageView类是唯一的子类或提供布局参数为:

android:layout_height="match_parent"
android:layout_height="match_parent"

不幸的是，由于我的布局设计，我需要“wrap_content”为“layout_height”。当我把它改成这样的时候，图像在底部被裁剪了，我不能滚动或缩放到裁剪的区域。所以我看了一下ImageView的源，只是看看Android如何实现“onMeasure”，并改变MikeOrtiz的适应。< / p >

   @Override
protected void onMeasure (int widthMeasureSpec, int heightMeasureSpec)
{
super.onMeasure(widthMeasureSpec, heightMeasureSpec);


//**** ADDED THIS ********/////
int  w = (int) bmWidth;
int  h = (int) bmHeight;
width = resolveSize(w, widthMeasureSpec);
height = resolveSize(h, heightMeasureSpec);
//**** END ********///


// width = MeasureSpec.getSize(widthMeasureSpec);   // REMOVED
// height = MeasureSpec.getSize(heightMeasureSpec); // REMOVED


//Fit to screen.
float scale;
float scaleX =  (float)width / (float)bmWidth;
float scaleY = (float)height / (float)bmHeight;


scale = Math.min(scaleX, scaleY);
matrix.setScale(scale, scale);
setImageMatrix(matrix);
saveScale = 1f;


// Center the image
redundantYSpace = (float)height - (scale * (float)bmHeight) ;
redundantXSpace = (float)width - (scale * (float)bmWidth);
redundantYSpace /= (float)2;
redundantXSpace /= (float)2;


matrix.postTranslate(redundantXSpace, redundantYSpace);


origWidth = width - 2 * redundantXSpace;
origHeight = height - 2 * redundantYSpace;
// origHeight = bmHeight;
right = width * saveScale - width - (2 * redundantXSpace * saveScale);
bottom = height * saveScale - height - (2 * redundantYSpace * saveScale);


setImageMatrix(matrix);
}

这里的resolveSize(int,int)是一个实用程序，用于将所需的大小与MeasureSpec施加的约束进行协调，其中:

参数:

 - size How big the view wants to be
- MeasureSpec Constraints imposed by the parent

返回:

 - The size this view should be."

本质上提供了一种行为更类似于图像加载时的原始ImageView类。还可以进行更多的更改，以支持修改纵横比的各种屏幕。但现在我希望这能有所帮助。感谢MikeOrtiz的原始代码，做得很好。

小开

我刚刚整合了Robert Foss的TouchImageView:它完美地开箱即用!谢谢!

我只是修改了一些代码，所以我可以从我的layout.xml实例化它。

只需添加两个构造函数

public TouchImageView(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}


public TouchImageView(Context context) {
super(context);
init(context);
}

并将旧的构造函数转换为init方法:

private void init(Context context){
//...old code ofconstructor of Robert Moss's code
}

小开

尝试使用ZoomView缩放任何其他视图。

http://code.google.com/p/android-zoom-view/它很容易，免费和有趣的使用!

小开

补充@Mike的回答。我还需要双击将图像恢复到第一次观看时的原始尺寸。所以我添加了一堆“orig…”实例变量，并添加了SimpleOnGestureListener。

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.widget.ImageView;


public class TouchImageView extends ImageView {


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;
int mode = NONE;


// Remember some things for zooming
PointF last = new PointF();
PointF start = new PointF();
float minScale = 1f;
float maxScale = 3f;
float[] m;


float redundantXSpace, redundantYSpace, origRedundantXSpace, origRedundantYSpace;;


float width, height;
static final int CLICK = 3;
static final float SAVE_SCALE = 1f;
float saveScale = SAVE_SCALE;


float right, bottom, origWidth, origHeight, bmWidth, bmHeight, origScale, origBottom,origRight;


ScaleGestureDetector mScaleDetector;
GestureDetector mGestureDetector;


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) {


boolean onDoubleTapEvent = mGestureDetector.onTouchEvent(event);
if (onDoubleTapEvent) {
// Reset Image to original scale values
mode = NONE;
bottom = origBottom;
right = origRight;
last = new PointF();
start = new PointF();
m = new float[9];
saveScale = SAVE_SCALE;
matrix = new Matrix();
matrix.setScale(origScale, origScale);
matrix.postTranslate(origRedundantXSpace, origRedundantYSpace);
setImageMatrix(matrix);
invalidate();
return true;
}




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_MOVE:
if (mode == 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);
}
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
}


});


mGestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
@Override
public boolean onDoubleTapEvent(MotionEvent e) {
return true;
}
});
}


@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 = (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 = (float) width / (float) bmWidth;
float scaleY = (float) height / (float) bmHeight;
scale = Math.min(scaleX, scaleY);
matrix.setScale(scale, scale);
setImageMatrix(matrix);
saveScale = SAVE_SCALE;
origScale = scale;


// Center the image
redundantYSpace = (float) height - (scale * (float) bmHeight);
redundantXSpace = (float) width - (scale * (float) bmWidth);
redundantYSpace /= (float) 2;
redundantXSpace /= (float) 2;


origRedundantXSpace = redundantXSpace;
origRedundantYSpace = redundantYSpace;


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);
origRight = right;
origBottom = bottom;
setImageMatrix(matrix);
}


}

小开

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imageDetail = (ImageView) findViewById(R.id.imageView1);
imageDetail.setOnTouchListener(new View.OnTouchListener() {


@Override
public boolean onTouch(View v, MotionEvent event) {
ImageView view = (ImageView) v;
System.out.println("matrix=" + savedMatrix.toString());
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
startPoint.set(event.getX(), event.getY());
mode = DRAG;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(midPoint, event);
mode = ZOOM;
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG) {
matrix.set(savedMatrix);
matrix.postTranslate(event.getX() - startPoint.x, event.getY() - startPoint.y);
} else if (mode == ZOOM) {
float newDist = spacing(event);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist / oldDist;
matrix.postScale(scale, scale, midPoint.x, midPoint.y);
}
}
break;
}
view.setImageMatrix(matrix);
return true;


}


@SuppressLint("FloatMath")
private float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return FloatMath.sqrt(x * x + y * y);
}


private void midPoint(PointF point, MotionEvent event) {
float x = event.getX(0) + event.getX(1);
float y = event.getY(0) + event.getY(1);
point.set(x / 2, y / 2);
}
});
}

和可绘制文件夹应该有bticn图像文件。完美的工作:)

小开

这是一个很晚添加到这个线程，但我一直在工作的图像视图，支持缩放和平移，并有几个功能，我没有发现在其他地方。这开始作为一种显示非常大的图像而不引起__abc0的方式，通过在缩小时对图像进行子采样，在放大时加载更高分辨率的tile。它现在支持在ViewPager中使用，手动旋转或使用EXIF信息(90°停止)，使用OnClickListener或你自己的GestureDetector或OnTouchListener覆盖选定的触摸事件，子类化来添加覆盖，缩放时平移，和抛出动量。

它不打算作为ImageView的一般使用替代品，因此不扩展它，并且不支持显示来自资源的图像，只支持资产和外部文件。它需要SDK 10。

源代码在GitHub上，有一个示例说明了在ViewPager中的使用。

https://github.com/davemorrissey/subsampling-scale-image-view

小开

如下所示就可以了。

@Override public boolean onTouch(View v,MotionEvent e)
{


tap=tap2=drag=pinch=none;
int mask=e.getActionMasked();
posx=e.getX();posy=e.getY();


float midx= img.getWidth()/2f;
float midy=img.getHeight()/2f;
int fingers=e.getPointerCount();


switch(mask)
{
case MotionEvent.ACTION_POINTER_UP:
tap2=1;break;


case MotionEvent.ACTION_UP:
tap=1;break;


case MotionEvent.ACTION_MOVE:
drag=1;
}
if(fingers==2){nowsp=Math.abs(e.getX(0)-e.getX(1));}
if((fingers==2)&&(drag==0)){ tap2=1;tap=0;drag=0;}
if((fingers==2)&&(drag==1)){ tap2=0;tap=0;drag=0;pinch=1;}


if(pinch==1)


{
if(nowsp>oldsp)scale+=0.1;
if(nowsp<oldsp)scale-=0.1;
tap2=tap=drag=0;
}
if(tap2==1)
{
scale-=0.1;
tap=0;drag=0;
}
if(tap==1)
{
tap2=0;drag=0;
scale+=0.1;
}
if(drag==1)
{
movx=posx-oldx;
movy=posy-oldy;
x+=movx;
y+=movy;
tap=0;tap2=0;
}
m.setTranslate(x,y);
m.postScale(scale,scale,midx,midy);
img.setImageMatrix(m);img.invalidate();
tap=tap2=drag=none;
oldx=posx;oldy=posy;
oldsp=nowsp;
return true;
}




public void onCreate(Bundle b)
{
super.onCreate(b);


img=new ImageView(this);
img.setScaleType(ImageView.ScaleType.MATRIX);
img.setOnTouchListener(this);


path=Environment.getExternalStorageDirectory().getPath();
path=path+"/DCIM"+"/behala.jpg";
byte[] bytes;
bytes=null;
try{
FileInputStream fis;
fis=new FileInputStream(path);
BufferedInputStream bis;
bis=new BufferedInputStream(fis);
bytes=new byte[bis.available()];
bis.read(bytes);
if(bis!=null)bis.close();
if(fis!=null)fis.close();


}
catch(Exception e)
{
ret="Nothing";
}
Bitmap bmp=BitmapFactory.decodeByteArray(bytes,0,bytes.length);


img.setImageBitmap(bmp);


setContentView(img);
}

要查看完整的程序，请参见这里:程序放大图像在android

我如何获得图像缩放功能?

更新

使用

: viewpage