Android編程之滑動(dòng)按鈕事件實(shí)例詳解

import Android.app.Activity;
import android.os.Bundle;
import android.widget.Toast;
public class Main extends Activity implements OnChangedListener {
  /** Called when the activity is first created. */
  @Override
  public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);
    SlipButton myBtn =(SlipButton) findViewById(R.id.slipBtn);//獲得指定控件
    myBtn.SetOnChangedListener(this);//為控件設(shè)置監(jiān)聽(tīng)器
  }
  @Override
  public void OnChanged(boolean CheckState) {//當(dāng)按鈕狀態(tài)被改變時(shí)
    // TODO Auto-generated method stub
    if(CheckState)
      Toast.makeText(this,"打開(kāi)了..." , Toast.LENGTH_SHORT).show();
    else
      Toast.makeText(this,"關(guān)閉了..." , Toast.LENGTH_SHORT).show();
  }
}

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Rect;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
public class SlipButton extends View implements OnTouchListener{
  private boolean NowChoose = false;//記錄當(dāng)前按鈕是否打開(kāi),true為打開(kāi),flase為關(guān)閉
  private boolean OnSlip = false;//記錄用戶是否在滑動(dòng)的變量
  private float DownX,NowX;//按下時(shí)的x,當(dāng)前的x,
  private Rect Btn_On,Btn_Off;//打開(kāi)和關(guān)閉狀態(tài)下,游標(biāo)的Rect
  private boolean isChgLsnOn = false;
  private OnChangedListener ChgLsn;
  private Bitmap bg_on,bg_off,slip_btn;
  public SlipButton(Context context) {
    super(context);
    // TODO Auto-generated constructor stub
    init();
  }
  public SlipButton(Context context, AttributeSet attrs) {
    super(context, attrs);
    // TODO Auto-generated constructor stub
    init();
  }
  private void init(){//初始化
    //載入圖片資源
    bg_on = BitmapFactory.decodeResource(getResources(), R.drawable.slip_bg_on);
    bg_off = BitmapFactory.decodeResource(getResources(), R.drawable.slip_bg_off);
    slip_btn = BitmapFactory.decodeResource(getResources(), R.drawable.slip_btn);
    //獲得需要的Rect數(shù)據(jù)
    Btn_On = new Rect(0,0,slip_btn.getWidth(),slip_btn.getHeight());
    Btn_Off = new Rect(
        bg_off.getWidth()-slip_btn.getWidth(),
        0,
        bg_off.getWidth(),
        slip_btn.getHeight());
    setOnTouchListener(this);//設(shè)置監(jiān)聽(tīng)器,也可以直接復(fù)寫OnTouchEvent
  }
  @Override
  protected void onDraw(Canvas canvas) {//繪圖函數(shù)
    // TODO Auto-generated method stub
    super.onDraw(canvas);
    Matrix matrix = new Matrix();
    Paint paint = new Paint();
    float x;
    {
      if(NowX<(bg_on.getWidth()/2))//滑動(dòng)到前半段與后半段的背景不同,在此做判斷
        canvas.drawBitmap(bg_off,matrix, paint);//畫出關(guān)閉時(shí)的背景
      else
        canvas.drawBitmap(bg_on,matrix, paint);//畫出打開(kāi)時(shí)的背景
      if(OnSlip)//是否是在滑動(dòng)狀態(tài),
      {
        if(NowX >= bg_on.getWidth())//是否劃出指定范圍,不能讓游標(biāo)跑到外頭,必須做這個(gè)判斷
          x = bg_on.getWidth()-slip_btn.getWidth()/2;//減去游標(biāo)1/2的長(zhǎng)度...
        else
          x = NowX - slip_btn.getWidth()/2;
      }else{//非滑動(dòng)狀態(tài)
        if(NowChoose)//根據(jù)現(xiàn)在的開(kāi)關(guān)狀態(tài)設(shè)置畫游標(biāo)的位置
          x = Btn_Off.left;
        else
          x = Btn_On.left;
      }
    if(x<0)//對(duì)游標(biāo)位置進(jìn)行異常判斷...
      x = 0;
    else if(x>bg_on.getWidth()-slip_btn.getWidth())
      x = bg_on.getWidth()-slip_btn.getWidth();
    canvas.drawBitmap(slip_btn,x, 0, paint);//畫出游標(biāo).
    }
  }
  @Override
  public boolean onTouch(View v, MotionEvent event) {
    // TODO Auto-generated method stub
    switch(event.getAction())//根據(jù)動(dòng)作來(lái)執(zhí)行代碼
    {
    case MotionEvent.ACTION_MOVE://滑動(dòng)
      NowX = event.getX();
      break;
    case MotionEvent.ACTION_DOWN://按下
    if(event.getX()>bg_on.getWidth()||event.getY()>bg_on.getHeight())
      return false;
      OnSlip = true;
      DownX = event.getX();
      NowX = DownX;
      break;
    case MotionEvent.ACTION_UP://松開(kāi)
      OnSlip = false;
      boolean LastChoose = NowChoose;
      if(event.getX()>=(bg_on.getWidth()/2))
        NowChoose = true;
      else
        NowChoose = false;
      if(isChgLsnOn&&(LastChoose!=NowChoose))//如果設(shè)置了監(jiān)聽(tīng)器,就調(diào)用其方法..
        ChgLsn.OnChanged(NowChoose);
      break;
    default:
    }
    invalidate();//重畫控件
    return true;
  }
  public void SetOnChangedListener(OnChangedListener l){//設(shè)置監(jiān)聽(tīng)器,當(dāng)狀態(tài)修改的時(shí)候
    isChgLsnOn = true;
    ChgLsn = l;
  }
}

package CMD100.demo.slipButton;
public interface OnChangedListener {
  abstract void OnChanged(boolean CheckState);
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:orientation="vertical"
  android:layout_width="fill_parent"
  android:layout_height="fill_parent"
  >
<TextView
  android:layout_width="fill_parent"
  android:layout_height="wrap_content"
  android:text="@string/hello"
  />
<LinearLayout
  android:orientation = "horizontal"
  android:layout_width = "fill_parent"
  android:layout_height = "wrap_content"
  android:background = "#ff0000"
  >
  <TextView
    android:text = "測(cè)試:"
    android:layout_width = "wrap_content"
    android:layout_height = "wrap_content"
    />
  <CMD100.demo.slipButton.SlipButton
    android:id = "@+id/slipBtn"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft = "10sp"
  />
</LinearLayout>
</LinearLayout>

<[包名].SlipButton
    android:id = "@+id/slipBtn"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    />

SlipButton myBtn =(SlipButton) findViewById(R.id.slipBtn);
myBtn.SetOnChangedListener(...);