滑块按钮
滑块按钮的实现
运行的效果：
用到的图片：（放置到drawable_xhdpi目录下）
public class SlipButton extends View{
private Bitmap bitmapDrawUnderSlid;
private Bitmap bitmapDrawSlid;
private Paint paint;
private int backWidth; //滑座图片的宽度
private int slidWidth; //滑块图片的宽度
private float location; //手触摸的位置
private boolean isOn = true; //是打开还是关闭
private boolean isSliding = false; //是否正在滑动
public SlipButton(Context context,AttributeSetattrs) {
super(context);
init();
}
/**
* 初始化参数
*/
public void init(){
bitmapDrawUnderSlid = BitmapFactory.decodeResource(getResources(),R.drawable.slid_button_background);
bitmapDrawSlid = BitmapFactory.decodeResource(getResources(),R.drawable.slid_button);
backWidth = bitmapDrawUnderSlid.getWidth();
slidWidth = bitmapDrawSlid.getWidth();
paint = new Paint();
}
/**
* 重写view的onDraw函数
*/
@Override
protected void onDraw(Canvas canvas) {
if(isSliding){
}else{
if(location > backWidth/2 - slidWidth/2){
location = backWidth/2;
}else{
location = 0;
}
}
canvas.drawBitmap(bitmapDrawUnderSlid, 0, 0, paint);
canvas.drawBitmap(bitmapDrawSlid,location, 0, paint);
}
/**
* 控制滑块的移动，并且会重新设置移动的位置的参数
*/
@Override
public boolean onTouchEvent(MotionEventevent) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:{ //手按下的时候
location = event.getX();
isSliding = true;
if(location > backWidth - slidWidth){
location = backWidth - slidWidth;
isOn = false;
}else if(location < slidWidth/2){
location = 0;
isOn = true;
}else{
location=location - slidWidth/2;
}
break;
}
case MotionEvent.ACTION_UP:{ //手指离开的时候
location = event.getX();
isSliding = false;
if(location > backWidth - slidWidth){
location = backWidth - slidWidth;
isOn = false;
}else if(location < slidWidth/2){
location = 0;
isOn = true;
}else{
location=location - slidWidth/2;
}
break;
}
case MotionEvent.ACTION_MOVE:{ //手指移动的时候
isSliding = true;
location = event.getX();
if(location > backWidth - slidWidth){
location = backWidth - slidWidth;
isOn = false;
}else if(location < slidWidth/2){
isOn = true;
location = 0;
}else{
location=location - slidWidth/2;
}
break;
}
default:break;
}
invalidate(); //此函数是view自带的函数，用于调用onDraw函数重新绘制
return true;
}
}