我正在创建一个应用程序，我在同一个ImageView上实现各种缩放功能。我已经编写了用于捏缩放的代码，它没有显示任何错误或异常，但它无法正常工作。我使用GestureDetector进行双击和滑动功能，并使用ScaleGestureDetector进行捏缩放
这是我的代码有问题吗？
public class SecondActivity extends AppCompatActivity {
ImageView iv;
private Matrix matrix = new Matrix();
private Matrix original_matrix = new Matrix();
private float x1,x2;
static final int MIN_DISTANCE = 150;
private Matrix matrix_scale=new Matrix();
int view_height;
int view_width;
int drawable_height;
int drawable_width;
Drawable drawable;
Bitmap bmp;
private float scale = 1f;
private ScaleGestureDetector SGD;
private Matrix matrix_pinch=new Matrix();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
setContentView(R.layout.activity_second);
iv = (ImageView) findViewById(R.id.iv_demo_gestures);
final Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
getSupportActionBar().setDisplayHomeAsUpEnabled(true);
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
bmp = Bitmap.createScaledBitmap(BitmapFactory.decodeResource(
getResources(), R.drawable.demoimg), size.x, size.y, true);
iv.setImageBitmap(bmp);
view_height=iv.getHeight();
view_width=iv.getWidth();
drawable=iv.getDrawable();
drawable_height=drawable.getMinimumHeight();
drawable_width=drawable.getMinimumWidth();
SGD = new ScaleGestureDetector(this,new ScaleListener());
iv.setOnTouchListener(new View.OnTouchListener() {
private GestureDetector gestureDetector = new GestureDetector(SecondActivity.this, new GestureDetector.SimpleOnGestureListener() {
int check_zoom_state = 0;
@Override
public boolean onDoubleTap(MotionEvent e) {
switch (check_zoom_state) {
case 0:
float scalefactor = Math.max(1.1f, Math.min(3.0f, 4.0f));
float x = e.getX();
float y = e.getY();
matrix.setScale(scalefactor, scalefactor, x, y);
iv.setImageMatrix(matrix);
check_zoom_state = 1;
break;
case 1:
//iv.setImageMatrix(original_matrix);
// iv.setAdjustViewBounds(true);
iv.setBackgroundResource(R.drawable.demoimg);
float scale_X = view_width / drawable_width;
float scale_Y = view_height / drawable_height;
original_matrix.setScale(scale_X, scale_Y);
iv.setImageMatrix(original_matrix);
check_zoom_state = 0;
break;
default:
float scalefactor1 = Math.max(1.1f, Math.min(3.0f, 4.0f));
float x1 = e.getX();
float y1 = e.getY();
matrix.setScale(scalefactor1, scalefactor1, x1, y1);
iv.setImageMatrix(matrix);
check_zoom_state = 1;
}
return super.onDoubleTap(e);
}
@Override
public void onLongPress(MotionEvent event) {
//iv.setImageMatrix(original_matrix);
/* Toast.makeText(getApplicationContext(), "Long Pressed",
Toast.LENGTH_LONG).show();*/
//iv.setAdjustViewBounds(true);
iv.setBackgroundResource(R.drawable.demoimg);
float scale_X = view_width / drawable_width;
float scale_Y = view_height / drawable_height;
original_matrix.setScale(scale_X, scale_Y);
iv.setImageMatrix(original_matrix);
}
});
@Override
public boolean onTouch(View v, MotionEvent event) {
switch(event.getAction())
{
case MotionEvent.ACTION_DOWN:
x1 = event.getX();
break;
case MotionEvent.ACTION_UP:
x2 = event.getX();
float deltaX = x2 - x1;
if (Math.abs(deltaX) > MIN_DISTANCE)
{
// Left to Right swipe action
if (x2 > x1)
{
// Toast.makeText(getApplicationContext(), "Left to Right swipe [Next]", Toast.LENGTH_SHORT).show();
Intent intent = new Intent(SecondActivity.this, MainActivity.class);
startActivity(intent);
}
// Right to left swipe action
/*else
{
Toast.makeText(getApplicationContext(), "Right to Left swipe [Previous]", Toast.LENGTH_SHORT).show();
}*/
}
else
{
// consider as something else - a screen tap for example
}
break;
}
gestureDetector.onTouchEvent(event);
return true;
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == android.R.id.home) {
Intent intent = new Intent(SecondActivity.this, MainActivity.class);
startActivity(intent);
}
return super.onOptionsItemSelected(item);
}
private float spacing(MotionEvent event) {
float x = event.getX(0) - event.getX(1);
float y = event.getY(0) - event.getY(1);
return (float) Math.sqrt(x * x + y * y);
}
public boolean onTouchEvent(MotionEvent ev) {
SGD.onTouchEvent(ev);
return true;
}
private class ScaleListener extends ScaleGestureDetector.
SimpleOnScaleGestureListener {
@Override
public boolean onScale(ScaleGestureDetector detector) {
scale *= detector.getScaleFactor();
scale = Math.max(0.1f, Math.min(scale, 5.0f));
matrix_pinch.setScale(scale, scale);
iv.setImageMatrix(matrix_pinch);
return true;
}
}
}
答案 0 :(得分：0)
试试这个例子 - Multitouch Image
声明全局内部活动
//variable for counting two successive up-down events
int clickCount = 0;
//variable for storing the time of first click
long startTime;
//variable for calculating the total time
long duration;
//constant for defining the time duration between the click that can be considered as double-tap
static final int MAX_DURATION = 500;
对于Double Tap听力，您可以在OnTouch
switch(event.getAction() & MotionEvent.ACTION_MASK)
{
case MotionEvent.ACTION_DOWN:
startTime = System.currentTimeMillis();
clickCount++;
break;
case MotionEvent.ACTION_UP:
long time = System.currentTimeMillis() - startTime;
duration= duration + time;
if(clickCount == 2)
{
if(duration<= MAX_DURATION)
{
Toast.makeText(SecondActivity.this, "double tap", Toast.LENGTH_LONG).show();
}
clickCount = 0;
duration = 0;
break;
}
}