Android的：在两指放大/缩小 [英] android:two finger zoom in/out
本文介绍了Android的：在两指放大/缩小的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我在屏幕上绘制一个对象（矩形），现在我想补充两指缩放视口。我发现一些教程，是放大图像，我改变/补充说，我的应用程序，它运行但在输入/输出不起作用放大！没有错误也！
你能不能帮我修复呢？这是。一个好的方式来放大/缩小视图端口？
公共类android1扩展活动实现OnTouchListener {
/ **当第一次创建活动调用。 * /
@覆盖
公共无效的onCreate（捆绑savedInstanceState）{
super.onCreate（savedInstanceState）;
this.requestWindowFeature（Window.FEATURE_NO_TITLE）;
getWindow（）。setFlags（WindowManager.LayoutParams.FLAG_FULLSCREEN，
WindowManager.LayoutParams.FLAG_FULLSCREEN）;
GLSurfaceView视图=新GLSurfaceView（本）;
view.setRenderer（新OpenGLRenderer（））;
的setContentView（视图）;
view.setOnTouchListener（本）;
} 私有静态最后弦乐TAG =触摸;
//这些矩阵将用于移动和放大图像
字模=新的Matrix（）;
矩阵savedMatrix =新的Matrix（）; //我们可以在这3个国家之一
静态最终诠释NONE = 0;
静态最终诠释ZOOM = 2;
INT模式=无; //记住一些东西放大
的PointF开始=新的PointF（）;
的PointF中旬=新的PointF（）;
浮oldDist = 1F;
公共布尔onTouch（视图V，MotionEvent事件）{
开关（event.getAction（）及MotionEvent.ACTION_MASK）{
案例MotionEvent.ACTION_DOWN：
savedMatrix.set（矩阵）;
start.set（event.getX（），event.getY（））;
Log.d（TAG模式= DRAG）; 打破;
案例MotionEvent.ACTION_POINTER_DOWN：
oldDist =间距（事件）;
Log.d（TAGoldDist =+ oldDist）;
如果（oldDist＆GT; 10F）{
savedMatrix.set（矩阵）;
中点（中，事件）;
模式= ZOOM;
Log.d（TAG模式= ZOOM）;
}
打破;
案例MotionEvent.ACTION_UP：
案例MotionEvent.ACTION_POINTER_UP：
模式=无;
Log.d（TAG模式= NONE）;
打破;
案例MotionEvent.ACTION_MOVE： 如果（==模式ZOOM）{
浮newDist =间距（事件）;
Log.d（TAGnewDist =+ newDist）;
如果（newDist＆GT; 10F）{
matrix.set（savedMatrix）;
浮规模= newDist / oldDist;
matrix.postScale（规模化，规模化，mid.x，mid.y）;
}
}
打破;
} 返回true; //表示事件已处理
} / **显示在LogCat中查看事件，调试* /
私人无效dumpEvent（MotionEvent事件）{
字符串名称[] = {DOWN，UP，MOVE，取消，外，
POINTER_DOWN，POINTER_UP，7？，8？，9？ };
StringBuilder的SB =新的StringBuilder（）;
INT行动= event.getAction（）;
INT行动code =动作＆安培; MotionEvent.ACTION_MASK;
sb.append（事件响应_）追加（名称[动作code]）;
如果（动作code == MotionEvent.ACTION_POINTER_DOWN
||行动code == MotionEvent.ACTION_POINTER_UP）{
sb.append（（PID）.append（
作用＆gt;＆GT; MotionEvent.ACTION_POINTER_ID_SHIFT）;
sb.append（））;
}
sb.append（[）;
的for（int i = 0; I＆LT; event.getPointerCount（）;我++）{
。sb.append（＃）追加（ⅰ）;
sb.append（（PID）.append（event.getPointerId（ⅰ））;
sb.append（）=）追加（（int）的event.getX（ⅰ））。
。sb.append（，）附加（（int）的event.getY（ⅰ））;
如果第（i + 1＆下; event.getPointerCount（））
sb.append（;）;
}
sb.append（]）;
Log.d（TAG，sb.toString（））;
} / **确定第一两个手指之间的空间* /
私人浮动间距（MotionEvent事件）{
浮X = event.getX（0） - event.getX（1）;
浮Y = event.getY（0） - event.getY（1）;
返回FloatMath.sqrt（X * X + Y * Y）;
} / **计算前两个手指的中点* /
私人无效中点（点的PointF，MotionEvent事件）{
浮X = event.getX（0）+ event.getX（1）;
浮Y = event.getY（0）+ event.getY（1）;
point.set（X / 2，Y / 2）;
}
}
解决方案
你正确设置矩阵，但你不把它应用到你的观点。在你onTouch活动结束：
v.setImageMatrix（矩阵）;
I draw an object (rectangle) on the screen and now I want to add two finger zooming to the viewport . I find some tutorial that was for zooming into an image , I changed/added that to my app , it runs but zoom in/out does not work! There's no error also ! could you help me fixing that ? is this agood way to zoom in/out of view port?
public class android1 extends Activity implements OnTouchListener {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
GLSurfaceView view = new GLSurfaceView(this);
view.setRenderer(new OpenGLRenderer());
setContentView(view);
view.setOnTouchListener(this);
}
private static final String TAG = "Touch";
// 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 ZOOM = 2;
int mode = NONE;
// Remember some things for zooming
PointF start = new PointF();
PointF mid = new PointF();
float oldDist = 1f;
public boolean onTouch(View v, MotionEvent event) {
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
savedMatrix.set(matrix);
start.set(event.getX(), event.getY());
Log.d(TAG, "mode=DRAG");
break;
case MotionEvent.ACTION_POINTER_DOWN:
oldDist = spacing(event);
Log.d(TAG, "oldDist=" + oldDist);
if (oldDist > 10f) {
savedMatrix.set(matrix);
midPoint(mid, event);
mode = ZOOM;
Log.d(TAG, "mode=ZOOM");
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_POINTER_UP:
mode = NONE;
Log.d(TAG, "mode=NONE");
break;
case MotionEvent.ACTION_MOVE:
if (mode == ZOOM) {
float newDist = spacing(event);
Log.d(TAG, "newDist=" + newDist);
if (newDist > 10f) {
matrix.set(savedMatrix);
float scale = newDist / oldDist;
matrix.postScale(scale, scale, mid.x, mid.y);
}
}
break;
}
return true; // indicate event was handled
}
/** 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(TAG, sb.toString());
}
/** 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);
}
}
解决方案
You're setting the matrix correctly but you don't apply it to your view. At the end of your onTouch event:
v.setImageMatrix(matrix);
这篇关于Android的：在两指放大/缩小的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
查看全文
