Android模拟实现滑动解锁界面

<?xml version="1.0" encoding="utf-8"? 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools" android:id="@+id/activity_main"
android:layout_width="match_parent" android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
android:gravity="center_horizontal"
tools:context="com.example.a7_.MainActivity" 

<com.example.a7_.MyView
 android:layout_alignParentBottom="true"
 android:id="@+id/mv"
 android:background="@mipmap/lockviewbg"
 android:layout_width="wrap_content"
 android:layout_height="wrap_content" / 
</RelativeLayout 

package com.example.a7_;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Paint;
import android.util.AttributeSet;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.widget.Scroller;
/**
* Created by Administrator on 2017.05.28.0028.
*/
public class MyView extends View {
private final Bitmap slidBitmap;
private final Bitmap bgBitmap;
private int startx;
private int destance;
private float endx;
private final Scroller scroller;
public MyView(Context context, AttributeSet attrs) {
super(context, attrs);
//加载图片资源
slidBitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.switch_button);
bgBitmap = BitmapFactory.decodeResource(getResources(), R.mipmap.lockviewbg);
//创建scroller对象
scroller = new Scroller(context);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
//设置自定义控件的宽和高,,以背景图片为标准
setMeasuredDimension(bgBitmap.getWidth(),bgBitmap.getHeight());
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
//绘制图片
canvas.drawBitmap(slidBitmap,0,0,null);
}
//设置滑块的触摸事件
@Override
public boolean onTouchEvent(MotionEvent event) {
switch (event.getAction()){
case MotionEvent.ACTION_DOWN:
//当手指按下的时候,记录坐标
startx = (int) event.getX();
break;
case MotionEvent.ACTION_MOVE:
//当手指移动的时候,记录移动的距离
destance = (int)(event.getX()-startx);
//限制滑块移动的区间
if (destance<0){
destance = 0;
}else if (destance bgBitmap.getWidth()-slidBitmap.getWidth()){
destance = bgBitmap.getWidth()-slidBitmap.getWidth();
}
//将滑块移动至该位置
scrollTo( -destance,0);
break;
case MotionEvent.ACTION_UP:
//当手指离开时,记录手指离开的位置
if (destance<bgBitmap.getWidth()-slidBitmap.getWidth()){
//手指抬起时,如果滑块不在右边,那就让他回到左边
startx = destance;
int dx = 0-destance;
scroller.startScroll(startx,0,dx,0);
invalidate();
}else {
//开启解锁
listener.onUnlock(this);
}
break;
}
invalidate();
return true;
}
//重写computeScroll方法 调用invalidate之后 会调用draw draw会调用到这个computeScroll
@Override
public void computeScroll() {
if (scroller.computeScrollOffset()){
//获取滑块当前的位置
int currx = scroller.getCurrX();
scrollTo(-currx,0);
//重新绘制
invalidate();
}
}
//设置一个解锁的接口
interface onUnLockListener{
void onUnlock(MyView view);
}
private onUnLockListener listener;
public void setOnLockListener(onUnLockListener listener){
this.listener = listener;
}
}
##核心代码
package com.example.a7_;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
private MyView myView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//初始化控件
myView = (MyView) findViewById(R.id.mv);
//设置监听事件
myView.setOnLockListener(new MyView.onUnLockListener() {
@Override
public void onUnlock(MyView view) {
//触发监听,结束页面
finish();
}
});
}
}