我已经阅读过相同问题的先前问题,但我仍然存在。
我有一个自定义ImageView
类,我试图在我的xml布局中使用ImageView
这样我可以缩放。(在stackoverflow上得到了示例)问题在于我尝试使用自定义ImageView
时的xml我收到此错误:
java.lang.ClassNotFoundException: NonActivities.TouchImageView$ScaleListener
at org.jetbrains.android.uipreview.ProjectClassLoader.load(ProjectClassLoader.java:91)
at com.android.tools.idea.rendering.RenderClassLoader.findClass(RenderClassLoader.java:55)
at org.jetbrains.android.uipreview.ProjectClassLoader.findClass(ProjectClassLoader.java:53)
at java.lang.ClassLoader.loadClass(ClassLoader.java:425)
at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
at NonActivities.TouchImageView.sharedConstructing(TouchImageView.java:52)
at NonActivities.TouchImageView.<init>(TouchImageView.java:46)
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
我读到你必须改变构造函数以接受2个参数,这个类有:
public TouchImageView(Context context, AttributeSet attrs) {
super(context, attrs);
sharedConstructing(context);
}
这是xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<NonActivities.TouchImageView
android:layout_width="50dp"
android:layout_height="50dp"
android:id="@+id/imageView"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_marginLeft="10dp"
android:layout_marginTop="10dp" />
</RelativeLayout>
有关为何发生这种情况的任何建议?
修改 这是整个课程(学分归于原创海报)
package NonActivities;
import android.content.Context;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.View;
import android.widget.ImageView;
public class TouchImageView extends ImageView {
Matrix 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;
int viewWidth, viewHeight;
static final int CLICK = 3;
float saveScale = 1f;
protected float origWidth, origHeight;
int oldMeasuredWidth, oldMeasuredHeight;
ScaleGestureDetector mScaleDetector;
Context context;
public TouchImageView(Context context) {
super(context);
sharedConstructing(context);
}
public TouchImageView(Context context, AttributeSet attrs) {
super(context, attrs);
sharedConstructing(context);
}
private void sharedConstructing(Context context) {
super.setClickable(true);
this.context = context;
mScaleDetector = new ScaleGestureDetector(context, new ScaleListener());
matrix = new Matrix();
m = new float[9];
setImageMatrix(matrix);
setScaleType(ScaleType.MATRIX);
setOnTouchListener(new OnTouchListener() {
@Override
public boolean onTouch(View v, MotionEvent event) {
mScaleDetector.onTouchEvent(event);
PointF curr = new PointF(event.getX(), event.getY());
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
last.set(curr);
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 fixTransX = getFixDragTrans(deltaX, viewWidth,
origWidth * saveScale);
float fixTransY = getFixDragTrans(deltaY, viewHeight,
origHeight * saveScale);
matrix.postTranslate(fixTransX, fixTransY);
fixTrans();
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
}
});
}
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 origScale = saveScale;
saveScale *= mScaleFactor;
if (saveScale > maxScale) {
saveScale = maxScale;
mScaleFactor = maxScale / origScale;
} else if (saveScale < minScale) {
saveScale = minScale;
mScaleFactor = minScale / origScale;
}
if (origWidth * saveScale <= viewWidth
|| origHeight * saveScale <= viewHeight)
matrix.postScale(mScaleFactor, mScaleFactor, viewWidth / 2,
viewHeight / 2);
else
matrix.postScale(mScaleFactor, mScaleFactor,
detector.getFocusX(), detector.getFocusY());
fixTrans();
return true;
}
}
void fixTrans() {
matrix.getValues(m);
float transX = m[Matrix.MTRANS_X];
float transY = m[Matrix.MTRANS_Y];
float fixTransX = getFixTrans(transX, viewWidth, origWidth * saveScale);
float fixTransY = getFixTrans(transY, viewHeight, origHeight
* saveScale);
if (fixTransX != 0 || fixTransY != 0)
matrix.postTranslate(fixTransX, fixTransY);
}
float getFixTrans(float trans, float viewSize, float contentSize) {
float minTrans, maxTrans;
if (contentSize <= viewSize) {
minTrans = 0;
maxTrans = viewSize - contentSize;
} else {
minTrans = viewSize - contentSize;
maxTrans = 0;
}
if (trans < minTrans)
return -trans + minTrans;
if (trans > maxTrans)
return -trans + maxTrans;
return 0;
}
float getFixDragTrans(float delta, float viewSize, float contentSize) {
if (contentSize <= viewSize) {
return 0;
}
return delta;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
viewWidth = MeasureSpec.getSize(widthMeasureSpec);
viewHeight = MeasureSpec.getSize(heightMeasureSpec);
//
// Rescales image on rotation
//
if (oldMeasuredHeight == viewWidth && oldMeasuredHeight == viewHeight
|| viewWidth == 0 || viewHeight == 0)
return;
oldMeasuredHeight = viewHeight;
oldMeasuredWidth = viewWidth;
if (saveScale == 1) {
// Fit to screen.
float scale;
Drawable drawable = getDrawable();
if (drawable == null || drawable.getIntrinsicWidth() == 0
|| drawable.getIntrinsicHeight() == 0)
return;
int bmWidth = drawable.getIntrinsicWidth();
int bmHeight = drawable.getIntrinsicHeight();
Log.d("bmSize", "bmWidth: " + bmWidth + " bmHeight : " + bmHeight);
float scaleX = (float) viewWidth / (float) bmWidth;
float scaleY = (float) viewHeight / (float) bmHeight;
scale = Math.min(scaleX, scaleY);
matrix.setScale(scale, scale);
// Center the image
float redundantYSpace = (float) viewHeight
- (scale * (float) bmHeight);
float redundantXSpace = (float) viewWidth
- (scale * (float) bmWidth);
redundantYSpace /= (float) 2;
redundantXSpace /= (float) 2;
matrix.postTranslate(redundantXSpace, redundantYSpace);
origWidth = viewWidth - 2 * redundantXSpace;
origHeight = viewHeight - 2 * redundantYSpace;
setImageMatrix(matrix);
}
fixTrans();
}
}
答案 0 :(得分:1)
在layout
更改此
<NonActivities.TouchImageView
android:layout_width="50dp"
android:layout_height="50dp"
android:id="@+id/imageView"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_marginLeft="10dp"
android:layout_marginTop="10dp" />
将 yourpackagename 设为com.example.myapp
<com.example.myapp.TouchImageView
android:layout_width="50dp"
android:layout_height="50dp"
android:id="@+id/imageView"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_marginLeft="10dp"
android:layout_marginTop="10dp" />
答案 1 :(得分:0)
您必须像这样更改XML代码:
<com.example.app.TouchImageView
android:layout_width="50dp"
android:layout_height="50dp"
android:id="@+id/imageView"
android:layout_alignParentTop="true"
android:layout_alignParentLeft="true"
android:layout_marginLeft="10dp"
android:layout_marginTop="10dp" />
其中com.example.app是您的自定义类TouchImageView。
所在的包尝试更改您的软件包,因为当您在Android中创建新项目时,如果您按照自己的意愿进行操作,请说:Package name must have at least two identifiers.