在我的Android应用程序中,我需要创建可缩放的活动。我找到了用于缩放线性布局here的有用代码。但在我的应用程序中,几个活动以scrollview开头,此代码无法识别scrollview。如何为可滚动活动进行捏缩放? 这是我的布局之一。
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/scrollViewZoom"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_centerVertical="true" >
<LinearLayout
android:id="@+id/wd_content"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="10dp"
android:orientation="vertical" >
<!-- Start Circle -->
<TableRow
android:id="@+id/row_circl1"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="center"
android:layout_marginTop="30dp"
android:background="@color/purple_color" >
<RelativeLayout
android:id="@+id/circle_layout1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@color/white_color" >
<ImageView
android:id="@+id/img_engin_circle1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:background="@drawable/circle_engin_bg"
android:contentDescription="TODO" />
</RelativeLayout>
<RelativeLayout
android:id="@+id/circle_layout2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@color/white_color" >
<ImageView
android:id="@+id/img_engin_circle2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:background="@drawable/circle_engin_bg"
android:contentDescription="TODO" />
</RelativeLayout>
</TableRow>
<TableRow
android:id="@+id/row_name_circle"
android:layout_width="wrap_content"
android:layout_height="match_parent"
android:layout_gravity="center"
android:layout_marginTop="30dp" >
<RelativeLayout
android:id="@+id/circle_name_layout1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="-15dp"
android:background="@color/white_color" >
<ImageView
android:id="@+id/img_name_circle1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:background="@drawable/circle_gauge_name"
android:contentDescription="TODO" />
</RelativeLayout>
<RelativeLayout
android:id="@+id/circle_name_layout2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="-15dp"
android:background="@color/white_color" >
<ImageView
android:id="@+id/img_name_circle2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:background="@drawable/circle_gauge_name"
android:contentDescription="TODO" />
</RelativeLayout>
</TableRow>
<!-- End Circle -->
</LinearLayout>
</ScrollView>
任何想法都会对我有所帮助。 感谢。
答案 0 :(得分:22)
确定。翻耕网后,终于找到了答案。
我发现滚动浏览的onTouchEvent()
不起作用,因此我必须使用dispatchTouchEvent()
而不是onTouchEvent()
。
在顶部你可以看到我的xml代码(在我的问题中)这里是我的活动代码,当然还有评论。
// step 1: add some instance
private float mScale = 1f;
private ScaleGestureDetector mScaleDetector;
GestureDetector gestureDetector;
//step 2: create instance from GestureDetector(this step sholude be place into onCreate())
gestureDetector = new GestureDetector(this, new GestureListener());
// animation for scalling
mScaleDetector = new ScaleGestureDetector(this, new ScaleGestureDetector.SimpleOnScaleGestureListener()
{
@Override
public boolean onScale(ScaleGestureDetector detector)
{
float scale = 1 - detector.getScaleFactor();
float prevScale = mScale;
mScale += scale;
if (mScale < 0.1f) // Minimum scale condition:
mScale = 0.1f;
if (mScale > 10f) // Maximum scale condition:
mScale = 10f;
ScaleAnimation scaleAnimation = new ScaleAnimation(1f / prevScale, 1f / mScale, 1f / prevScale, 1f / mScale, detector.getFocusX(), detector.getFocusY());
scaleAnimation.setDuration(0);
scaleAnimation.setFillAfter(true);
ScrollView layout =(ScrollView) findViewById(R.id.scrollViewZoom);
layout.startAnimation(scaleAnimation);
return true;
}
});
// step 3: override dispatchTouchEvent()
@Override
public boolean dispatchTouchEvent(MotionEvent event) {
super.dispatchTouchEvent(event);
mScaleDetector.onTouchEvent(event);
gestureDetector.onTouchEvent(event);
return gestureDetector.onTouchEvent(event);
}
//step 4: add private class GestureListener
private class GestureListener extends GestureDetector.SimpleOnGestureListener {
@Override
public boolean onDown(MotionEvent e) {
return true;
}
// event when double tap occurs
@Override
public boolean onDoubleTap(MotionEvent e) {
// double tap fired.
return true;
}
}
非常感谢。
答案 1 :(得分:2)
感谢您的解决方案,我实现它有点不同,因为我的scrollview在片段而不是活动中,将所有逻辑委托给视图我建议在同一个自定义滚动视图中添加dispatchTouchEvent:
package com.your.package;
import android.content.Context;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.view.ScaleGestureDetector;
import android.view.animation.ScaleAnimation;
import android.widget.ScrollView;
import com.your.package.R;
public class CustomZoomScrollView extends ScrollView {
// step 1: add some instance
private float mScale = 1f;
private ScaleGestureDetector mScaleDetector;
GestureDetector gestureDetector;
public CustomZoomScrollView(Context context) {
super(context);
}
public CustomZoomScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
//step 2: create instance from GestureDetector(this step should be place into onCreate())
gestureDetector = new GestureDetector(getContext(), new GestureListener());
mScaleDetector = new ScaleGestureDetector(getContext(), new ScaleGestureDetector.SimpleOnScaleGestureListener()
{
@Override
public boolean onScale(ScaleGestureDetector detector)
{
float scale = 1 - detector.getScaleFactor();
float prevScale = mScale;
mScale += scale;
if (mScale < 0.1f) // Minimum scale condition:
mScale = 0.1f;
if (mScale > 10f) // Maximum scale condition:
mScale = 10f;
ScaleAnimation scaleAnimation = new ScaleAnimation(1f / prevScale, 1f / mScale, 1f / prevScale, 1f / mScale, detector.getFocusX(), detector.getFocusY());
scaleAnimation.setDuration(0);
scaleAnimation.setFillAfter(true);
getRootView().findViewById(R.id.svSeats).startAnimation(scaleAnimation);
return true;
}
});
}
// step 3: override dispatchTouchEvent()
@Override
public boolean dispatchTouchEvent(MotionEvent event) {
super.dispatchTouchEvent(event);
mScaleDetector.onTouchEvent(event);
gestureDetector.onTouchEvent(event);
return gestureDetector.onTouchEvent(event);
}
//step 4: add private class GestureListener
private class GestureListener extends GestureDetector.SimpleOnGestureListener {
@Override
public boolean onDown(MotionEvent e) {
return true;
}
// event when double tap occurs
@Override
public boolean onDoubleTap(MotionEvent e) {
// double tap fired.
return true;
}
}
}