本文实例讲述了Android编程实现可滑动的开关效果。分享给大家供大家参考，具体如下：
闲着没事，把之前写的一个Demo放上来分享下。就是一个开关，实现可滑动和动画效果。不是图片切换。
好了，先上图：
完整实例代码点击此处本站下载。
直接把自定义的这个View代码放上来，有注释应该很好理解：首先是布局：
<?xml version="1.0" encoding="utf-8"?><RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" android:id="@+id/sv_container" android:layout_width="230dip" android:layout_height="38dip" android:background="@drawable/usage_list_dark" > <ImageView android:id="@+id/iv_switch_cursor" android:layout_width="120dip" android:layout_height="36dip" android:layout_centerVertical="true" android:layout_marginLeft="0.5dip" android:layout_marginRight="0.5dip" android:background="@drawable/usage_list_green" /> <LinearLayout android:layout_width="fill_parent" android:layout_height="fill_parent" android:gravity="center" > <TextView android:id="@+id/switch_text_true" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:gravity="center" android:text="开" /> <TextView android:id="@+id/switch_text_false" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:gravity="center" android:text="关" /> </LinearLayout></RelativeLayout>
接着是这个View的代码，继承自LinearLayout ：
package com.lxb.switchdemo;import android.content.Context;import android.graphics.Color;import android.os.Handler;import android.os.Message;import android.view.LayoutInflater;import android.view.MotionEvent;import android.view.View;import android.view.View.OnClickListener;import android.view.animation.Animation;import android.view.animation.Animation.AnimationListener;import android.view.animation.LinearInterpolator;import android.view.animation.TranslateAnimation;import android.widget.ImageView;import android.widget.LinearLayout;import android.widget.RelativeLayout;import android.widget.TextView;public class SwitchView extends LinearLayout implements OnClickListener { private static final int FLAG_MOVE_TRUE = 1; // 向左滑动标识 private static final int FLAG_MOVE_FALSE = 2; // 向右滑动标识 private static final int HANDLE_LAYOUT_CURSOR = 100; // 处理调用开关的layout方法 private Context context; // 上下文对象 private RelativeLayout sv_container; // SwitchView的外层Layout private ImageView iv_switch_cursor; // 开关邮标的ImageView private TextView switch_text_true; // true的文字信息控件 private TextView switch_text_false; // false的文字信息控件 private boolean isChecked = true; // 是否已开 private boolean checkedChange = false; // isChecked是否有改变 private OnCheckedChangeListener onCheckedChangeListener; // 用于监听isChecked是否有改变 private int margin = 1; // 游标离边缘位置(这个值视图片而定, 主要是为了图片能显示正确) private int bg_left; // 背景左 private int bg_right; // 背景右 private int cursor_left; // 游标左部 private int cursor_top; // 游标顶部 private int cursor_right; // 游标右部 private int cursor_bottom; // 游标底部 private Animation animation; // 移动动画 private int currentFlag = FLAG_MOVE_TRUE; // 当前移动方向flag public SwitchView(Context context) { super(context); this.context = context; initView(); } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { super.onLayout(changed, l, t, r, b); // 获取所需要的值 bg_left = sv_container.getLeft(); bg_right = sv_container.getRight(); cursor_left = iv_switch_cursor.getLeft(); cursor_top = iv_switch_cursor.getTop(); cursor_right = iv_switch_cursor.getRight(); cursor_bottom = iv_switch_cursor.getBottom(); } private Handler mHandler = new Handler() { @Override public void handleMessage(Message msg) { switch(msg.what) { case HANDLE_LAYOUT_CURSOR: iv_switch_cursor.layout(cursor_left, cursor_top, cursor_right, cursor_bottom); break; } } }; public void onClick(View v) { // 控件点击时触发改变checked值 if(v == this) { changeChecked(!isChecked); } } /** * 初始化控件 */ private void initView() { LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE); View view = inflater.inflate(R.layout.switch_view, this); view.setOnClickListener(this); sv_container = (RelativeLayout) view.findViewById(R.id.sv_container); switch_text_true = (TextView) view.findViewById(R.id.switch_text_true); switch_text_false = (TextView) view.findViewById(R.id.switch_text_false); changeTextColor(); iv_switch_cursor = (ImageView) view.findViewById(R.id.iv_switch_cursor); iv_switch_cursor.setClickable(false); iv_switch_cursor.setOnTouchListener(new OnTouchListener() { int lastX; // 最后的X坐标 public boolean onTouch(View v, MotionEvent event) { switch(event.getAction()) { case MotionEvent.ACTION_DOWN: lastX = (int) event.getRawX(); cursor_left = v.getLeft(); cursor_top = v.getTop(); cursor_right = v.getRight(); cursor_bottom = v.getBottom(); break; case MotionEvent.ACTION_MOVE: int dx = (int) event.getRawX() - lastX; cursor_left = v.getLeft() + dx; cursor_right = v.getRight() + dx; // 超出边界处理 if(cursor_left <= bg_left + margin) { cursor_left = bg_left + margin; cursor_right = cursor_left + v.getWidth(); } if(cursor_right >= bg_right - margin) { cursor_right = bg_right - margin; cursor_left = cursor_right - v.getWidth(); } v.layout(cursor_left, cursor_top, cursor_right, cursor_bottom); lastX = (int) event.getRawX(); break; case MotionEvent.ACTION_UP: calculateIscheck(); break; } return true; } }); } /** * 计算处于true或是false区域, 并做改变处理 */ private void calculateIscheck() { float center = (float) ((bg_right - bg_left) / 2.0); float cursor_center = (float) ((cursor_right - cursor_left) / 2.0); if(cursor_left + cursor_center <= center) { changeChecked(true); } else { changeChecked(false); } } /** * 改变checked, 根据checked移动游标 * @param isChecked */ private void changeChecked(boolean isChecked) { if(this.isChecked != isChecked) { checkedChange = true; } else { checkedChange = false; } if(isChecked) { currentFlag = FLAG_MOVE_TRUE; } else { currentFlag = FLAG_MOVE_FALSE; } cursorMove(); } /** * 游标移动 */ private void cursorMove() { // 这里说明一点, 动画本可设置animation.setFillAfter(true) // 令动画进行完后停在最后位置. 但这里使用这样方式的话. // 再次拖动图片会出现异常(具体原因我没找到) // 所以最后只能使用onAnimationEnd回调方式再layout游标 animation = null; final int toX; if(currentFlag == FLAG_MOVE_TRUE) { toX = cursor_left - bg_left - margin; animation = new TranslateAnimation(0, -toX, 0, 0); } else { toX = bg_right - margin - cursor_right; animation = new TranslateAnimation(0, toX, 0, 0); } animation.setDuration(100); animation.setInterpolator(new LinearInterpolator()); animation.setAnimationListener(new AnimationListener() { public void onAnimationStart(Animation animation) { } public void onAnimationRepeat(Animation animation) { } public void onAnimationEnd(Animation animation) { // 计算动画完成后游标应在的位置 if(currentFlag == FLAG_MOVE_TRUE) { cursor_left -= toX; cursor_right = cursor_left + iv_switch_cursor.getWidth(); } else { cursor_right = bg_right - margin; cursor_left = cursor_right - iv_switch_cursor.getWidth(); } // 这里不能马上layout游标正确位置, 否则会有一点点闪屏 // 为了美观, 这里迟了一点点调用layout方法, 便不会闪屏 mHandler.sendEmptyMessageDelayed(HANDLE_LAYOUT_CURSOR, 5); // 这里是根据是不是改变了isChecked值进行一些操作 if(checkedChange) { isChecked = !isChecked; if(onCheckedChangeListener != null) { onCheckedChangeListener.onCheckedChanged(isChecked); } changeTextColor(); } } }); iv_switch_cursor.startAnimation(animation); } /** * 改变字体显示颜色 */ private void changeTextColor() { if(isChecked) { switch_text_true.setTextColor(Color.WHITE); switch_text_false.setTextColor(Color.GRAY); } else { switch_text_true.setTextColor(Color.GRAY); switch_text_false.setTextColor(Color.WHITE); } } /** * layout游标 */ private void layoutCursor() { if(isChecked) { cursor_left = bg_left + margin; cursor_right = bg_left + margin + iv_switch_cursor.getWidth(); } else { cursor_left = bg_right - margin - iv_switch_cursor.getWidth(); cursor_right = bg_right - margin; } iv_switch_cursor.layout(cursor_left, cursor_top, cursor_right, cursor_bottom); } /** * isChecked值改变监听器 */ public interface OnCheckedChangeListener { void onCheckedChanged(boolean isChecked); } public boolean isChecked() { return isChecked; } public void setChecked(boolean isChecked) { if(this.isChecked != isChecked) { this.isChecked = isChecked; if(onCheckedChangeListener != null) { onCheckedChangeListener.onCheckedChanged(isChecked); } layoutCursor(); } } public void setOnCheckedChangeListener( OnCheckedChangeListener onCheckedChangeListener) { this.onCheckedChangeListener = onCheckedChangeListener; }}
最后是Activity使用这个View:
package com.lxb.switchdemo;import android.app.Activity;import android.os.Bundle;import android.view.View;import android.view.View.OnClickListener;import android.widget.Button;import android.widget.LinearLayout;import android.widget.TextView;import android.widget.Toast;import com.lxb.switchdemo.SwitchView.OnCheckedChangeListener;public class Switch_demoActivity extends Activity implements OnClickListener { private LinearLayout layout; private TextView tv_showcheck; private SwitchView sv; private Button btn_set_true; private Button btn_set_false; private Button btn_getstate; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); layout = (LinearLayout) findViewById(R.id.layout); tv_showcheck = (TextView) findViewById(R.id.tv_showcheck); sv = new SwitchView(this); tv_showcheck.setText("当前状态: " + getState(sv.isChecked())); sv.setOnCheckedChangeListener(new OnCheckedChangeListener() { public void onCheckedChanged(boolean isChecked) { tv_showcheck.setText("当前状态: " + getState(isChecked)); } }); layout.addView(sv); btn_set_true = (Button) findViewById(R.id.btn_set_true); btn_set_false = (Button) findViewById(R.id.btn_set_false); btn_getstate = (Button) findViewById(R.id.btn_getstate); btn_set_true.setOnClickListener(this); btn_set_false.setOnClickListener(this); btn_getstate.setOnClickListener(this); } public void onClick(View v) { switch(v.getId()) { case R.id.btn_set_true: sv.setChecked(true); break; case R.id.btn_set_false: sv.setChecked(false); break; case R.id.btn_getstate: Toast.makeText(Switch_demoActivity.this, sv.isChecked() + "", Toast.LENGTH_SHORT).show(); break; } } private String getState(boolean state) { if(state) { return "开"; } return "关"; }}
实现起来还是很简单的，主要还是坐标什么的需要计算与调整。
当然可能还会有一些BUG存在，有需要的可以下下来自行修改，也可以和我讨论。
更多关于Android相关内容感兴趣的读者可查看本站专题：《Android通信方式总结》、《Android调试技巧与常见问题解决方法汇总》、《Android开发入门与进阶教程》、《Android多媒体操作技巧汇总(音频,视频,录音等)》、《Android基本组件用法总结》、《Android视图View技巧总结》、《Android布局layout技巧总结》及《Android控件用法总结》
希望本文所述对大家Android程序设计有所帮助。
从起点，到尽头，也许快乐，或有时孤独，
