标签：android android-imageview image-zoom
我已经在android中为imageView zoom..i做了一个简单的演示程序,尝试了下面的代码,但是当捏或点击时图像不会变焦..请帮忙
main.java
package com.example.imageviewzoomdemo;
import android.os.Bundle;
import android.annotation.SuppressLint;
import android.app.Activity;
import android.graphics.Matrix;
import android.graphics.PointF;
import android.util.FloatMath;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;
public class MainActivity extends Activity {
ImageView imageview;
Matrix matrix =new Matrix();
Matrix savedMatrix =new Matrix();
PointF start = new PointF();
PointF mid =new PointF();
float oldDist = 1f;
final static int NONE = 0;
final static int DRAG = 1;
final static int ZOOM = 2;
int mode = NONE;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
imageview=(ImageView)findViewById(R.id.imageView1);
imageview.setOnTouchListener(new 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);
start.set(event.getX(), event.getY());
mode = DRAG;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(mid, 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() - start.x,
event.getY() - start.y);
} else if (mode == ZOOM) {
float newDist = spacing(event);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist / oldDist;
matrix.postScale(scale, scale, mid.x, mid.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);
}
});
}
}
我正在获取图像,但是当我点击该图像时它不会缩放.
解决方法:
这个对我有用.试试看.
public class Touch implements OnTouchListener {
// 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;
@Override
public boolean onTouch(View v, MotionEvent event) {
// TODO Auto-generated method stub
ImageView view = (ImageView)v;
view.setScaleType(ImageView.ScaleType.MATRIX);
// Handle touch events here...
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
mode = DRAG;
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
if (oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(mid, 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() - start.x, event.getY() - start.y);
}
else if(mode == ZOOM)
{
float newDist = spacing(event);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist / oldDist;
matrix.postScale(scale, scale, mid.x, mid.y);
}
}
break;
}
view.setImageMatrix(matrix);
return true;
}
/** Determine the space between the first two fingers */
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);
}
/** Calculate the mid point of the first 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);
}
}
就像这样使用它
ImageView iv = (ImageView)findViewById(R.id.imageView1);
iv.setOnTouchListener(new Touch());
标签：android,android-imageview,image-zoom 来源： https://codeday.me/bug/20190825/1721274.html
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