有人可以指导我在Android中的多个视图上执行放大和缩小操作吗？我需要在触摸图像，文本视图时执行放大和缩小操作。什么应该是我的父布局？这是在触摸imageview时缩放图像的代码。如何缩放textview？请帮我。
// These matrices will be used to scale points of the image
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
// The 3 states (events) which the user is trying to perform
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
// these PointF objects are used to record the point(s) the user is touching
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
private void zoom(View v, MotionEvent event)
{
ImageView view = (ImageView) v;
view.setScaleType(ImageView.ScaleType.MATRIX);
float scale;
// dumpEvent(event);
// Handle touch events here...
switch (event.getAction() & MotionEvent.ACTION_MASK)
{
case MotionEvent.ACTION_DOWN:
// first finger down only
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
mode = DRAG;
break;
case MotionEvent.ACTION_UP: // first finger lifted
case MotionEvent.ACTION_POINTER_UP: // second finger lifted
mode = NONE;
break;
case MotionEvent.ACTION_POINTER_DOWN: // first and second finger down
oldDist = spacing(event);
if (oldDist > 5f)
{
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
}
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG)
{
matrix.set(savedMatrix);
matrix.postTranslate(event.getX() - start.x, event.getY() - start.y); // create the transformation in the matrix of points
}
else if (mode == ZOOM)
{
// pinch zooming
float newDist = spacing(event);
if (newDist > 5f)
{
matrix.set(savedMatrix);
scale = newDist / oldDist; // setting the scaling of the
// matrix...if scale > 1 means
// zoom in...if scale < 1 means
// zoom out
matrix.postScale(scale, scale, mid.x, mid.y);
}
}
break;
}
view.setImageMatrix(matrix); // display the transformation on screen
}
/*
* --------------------------------------------------------------------------
* Method: spacing Parameters: MotionEvent Returns: float Description:
*
* checks the spacing between the two fingers on touch
* ----------------------------------------------------
*/
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);
}
/*
* --------------------------------------------------------------------------
* Method: midPoint Parameters: PointF object, MotionEvent Returns: void
* Description: calculates the midpoint between the two fingers
* ------------------------------------------------------------
*/
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);
}
答案 0 :(得分：2)
以上是可以的，但你可以在下面看到::
在oncreate（）中，您必须对文本视图进行初始化并在其上设置ontouch事件，如下所示
TextView tv = (TextView)findViewById(R.id.name);
tv.setText("text");
tv.setOnTouchListener(this);
这里是完整的代码，包括你的代码:::
public class MyTextView extends Activity implements OnTouchListener{
private static final String TAG = "Touch";
@SuppressWarnings("unused")
private static final float MIN_ZOOM = 1f,MAX_ZOOM = 1f;
// These matrices will be used to scale points of the image
Matrix matrix = new Matrix();
Matrix savedMatrix = new Matrix();
// The 3 states (events) which the user is trying to perform
static final int NONE = 0;
static final int DRAG = 1;
static final int ZOOM = 2;
int mode = NONE;
// these PointF objects are used to record the point(s) the user is touching
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
TextView iv = new TextView(this);
iv.setText("text");
iv.setOnTouchListener(this);
setContentView(iv);
}
@Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
ImageView view = (ImageView) v;
view.setScaleType(ImageView.ScaleType.MATRIX);
float scale;
dumpEvent(event);
// Handle touch events here...
switch (event.getAction() & 255)
{
case MotionEvent.ACTION_DOWN: // first finger down only
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
Log.d(TAG, "mode=DRAG"); // write to LogCat
mode = DRAG;
break;
case MotionEvent.ACTION_UP: // first finger lifted
case 6: // second finger lifted
mode = NONE;
Log.d(TAG, "mode=NONE");
break;
case 5: // first and second finger down
oldDist = spacing(event);
Log.d(TAG, "oldDist=" + oldDist);
if (oldDist > 5f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
Log.d(TAG, "mode=ZOOM");
}
break;
case MotionEvent.ACTION_MOVE:
if (mode == DRAG)
{
matrix.set(savedMatrix);
matrix.postTranslate(event.getX() - start.x, event.getY() - start.y); // create the transformation in the matrix of points
}
else if (mode == ZOOM)
{
// pinch zooming
float newDist = spacing(event);
Log.d(TAG, "newDist=" + newDist);
if (newDist > 5f)
{
matrix.set(savedMatrix);
scale = newDist / oldDist; // setting the scaling of the
// matrix...if scale > 1 means
// zoom in...if scale < 1 means
// zoom out
matrix.postScale(scale, scale, mid.x, mid.y);
}
}
break;
}
view.setImageMatrix(matrix); // display the transformation on screen
return true; // indicate event was handled
}
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);
}
/*
* --------------------------------------------------------------------------
* Method: midPoint Parameters: PointF object, MotionEvent Returns: void
* Description: calculates the midpoint between the two fingers
* ------------------------------------------------------------
*/
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);
}
/** Show an event in the LogCat view, for debugging */
private void dumpEvent(MotionEvent 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("Touch Events ---------", sb.toString());
}
}
答案 1 :(得分：1)
要缩放文本视图，您可以使用与缩放图像相同的代码。但是您应该将textview更改为imageview，然后执行缩放操作。以下是将textview转换为imageview Converting a TextView->Bitmap->ImageView, and nothing's showing up
的链接答案 2 :(得分：1)
我找到了一个非常简单的解决方案来实现文本视图的放大/缩小。也许它有助于某人
package com.app;
import android.os.Bundle;
import android.util.TypedValue;
import android.view.MotionEvent;
import android.widget.TextView;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
public class MyActivity extends AppCompatActivity implements View.OnTouchListener{
public static final int TEXT_MAX_SIZE = 140;
public static final int TEXT_MIN_SIZE = 40;
private static final int STEP = 4;
private int mBaseDistZoomIn;
private int mBaseDistZoomOut;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.my_activity);
.
.
.
TextView viewById = (TextView) findViewById(R.id.some_text_view);
viewById.setOnTouchListener(this);
}
@Override
public boolean onTouch(View v, MotionEvent event) {
if (event.getPointerCount() == 2) {
TextView viewById = (TextView) findViewById(R.id.some_text_view);
int action = event.getAction();
int pure = action & MotionEvent.ACTION_MASK;
if (pure == MotionEvent.ACTION_POINTER_DOWN
&& viewById.getTextSize() <= TEXT_MAX_SIZE
&& viewById.getTextSize() >= TEXT_MIN_SIZE) {
mBaseDistZoomIn = getDistanceFromEvent(event);
mBaseDistZoomOut = getDistanceFromEvent(event);
} else {
int currentDistance = getDistanceFromEvent(event);
if (currentDistance > mBaseDistZoomIn) {
float finalSize = viewById.getTextSize() + STEP;
if (finalSize > TEXT_MAX_SIZE) {
finalSize = TEXT_MAX_SIZE;
}
viewById.setTextSize(TypedValue.COMPLEX_UNIT_PX, finalSize);
} else {
if (currentDistance < mBaseDistZoomOut) {
float finalSize = viewById.getTextSize() - STEP;
if (finalSize < TEXT_MIN_SIZE) {
finalSize = TEXT_MIN_SIZE;
}
viewById.setTextSize(TypedValue.COMPLEX_UNIT_PX, finalSize);
}
}
}
return true;
}
return false;
}
// good function to get the distance between the multiple touch
int getDistanceFromEvent(MotionEvent event) {
int dx = (int) (event.getX(0) - event.getX(1));
int dy = (int) (event.getY(0) - event.getY(1));
return (int) (Math.sqrt(dx * dx + dy * dy));
}
}
答案 3 :(得分：0)
first you should convert Textview to imageview.Next you should apply sample image view drag functionality.
-----------------------------
TextView tv = new TextView(this);
FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams(
FrameLayout.LayoutParams.FILL_PARENT,
FrameLayout.LayoutParams.FILL_PARENT);
tv.setLayoutParams(layoutParams);
tv.setText("Text");
tv.setTextColor(Color.BLACK);
tv.setBackgroundColor(Color.TRANSPARENT);
Bitmap testB;
testB = Bitmap.createBitmap(80, 100, Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(testB);
tv.layout(30, 40, 200, 100);
tv.draw(c);
ImageView iv = (ImageView) findViewById(R.id.imageView);
iv.setLayoutParams(layoutParams);
iv.setBackgroundColor(Color.GRAY);`enter code here`
iv.setImageBitmap(testB);
iv.setMaxHeight(80);
iv.setMaxWidth(200);
iv.setOnTouchListener(this);