Android实现图片双指缩放

本文实例为大家分享了android实现图片双指缩放的具体代码，供大家参考，具体内容如下

展示

源码

using android.app;
using android.os;
using android.util;
using android.views;
using android.widget;

namespace android_by_csharp
{
    [activity(label = "@string/app_name", theme = "@style/apptheme", mainlauncher = true)]
    public class mainactivity : activity
    {
        protected override void oncreate(bundle savedinstancestate)
        {
            base.oncreate(savedinstancestate);
            setcontentview(resource.layout.main);

            var avatar = findviewbyid<imageview>(resource.id.avatar);
            var distance = 0;
            if (avatar != null)
                avatar.touch += (sender, args) =>
                {
                    if (args.event == null) return;
                    // 双指按下
                    if ((args.event.action & motioneventactions.pointer2down) == motioneventactions.pointer2down)
                        distance = (int)distance(args.event);
                    // 双指抬起
                    else if ((args.event.action & motioneventactions.pointer2up) == motioneventactions.pointer2up)
                        toast.maketext(this, "双指抬起", toastlength.short)?.show();

                    // 移动,双指
                    if ((args.event.action & motioneventactions.move) == 0 || args.event.pointercount != 2) return;
                    var movedistance = distance(args.event);
                    avatar.scaley = avatar.scalex *= movedistance / distance;

                    if (movedistance / distance < 1)
                        toast.maketext(this, "缩小", toastlength.short)?.show();
                    else if (movedistance / distance > 1)
                        toast.maketext(this, "放大", toastlength.short)?.show();
                };
        }

        // 计算两个触摸点之间的距离
        private static float distance(motionevent motionevent)
        {
            var x = motionevent.getx(0) - motionevent.getx(1);
            var y = motionevent.gety(0) - motionevent.gety(1);
            return floatmath.sqrt(x * x + y * y);
        }
    }
}

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持。