Android带有删除按钮的EditText

package cc.textview5; 
import android.os.Bundle; 
import android.text.TextUtils; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
import android.widget.Toast; 
import android.app.Activity; 
/** 
 * Demo描述: 
 * 自定义控件实现带清除功能的EditText 
 * 
 * 学习资料: 
 * http://blog.csdn.net/xiaanming/article/details/11066685 
 * 
 * Thank you very much 
 */ 
public class MainActivity extends Activity { 
  private CleanableEditText mUserNameCleanableEditText; 
  private CleanableEditText mPassWordCleanableEditText; 
  private Button mLoginButton; 
  @Override 
  protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 
    init(); 
  } 
   
  private void init(){ 
    mUserNameCleanableEditText=(CleanableEditText) findViewById(R.id.userNameEditText); 
    mPassWordCleanableEditText=(CleanableEditText) findViewById(R.id.passwordEditText); 
    mLoginButton=(Button) findViewById(R.id.loginButton); 
    mLoginButton.setOnClickListener(new OnClickListenerImpl()); 
  } 
   
  private class OnClickListenerImpl implements OnClickListener { 
    @Override 
    public void onClick(View view) { 
      if (TextUtils.isEmpty(mUserNameCleanableEditText.getText())) { 
        mUserNameCleanableEditText.setShakeAnimation(); 
        Toast.makeText(MainActivity.this, "请输入用户名", Toast.LENGTH_SHORT).show(); 
      } 
 
      if (TextUtils.isEmpty(mPassWordCleanableEditText.getText())) { 
        mPassWordCleanableEditText.setShakeAnimation(); 
        Toast.makeText(MainActivity.this, "请输入密码", Toast.LENGTH_SHORT).show(); 
      } 
    } 
 
  } 
   
 
} 

package cc.textview5; 
 
import android.content.Context; 
import android.graphics.drawable.Drawable; 
import android.text.Editable; 
import android.text.TextWatcher; 
import android.util.AttributeSet; 
import android.view.MotionEvent; 
import android.view.View; 
import android.view.animation.Animation; 
import android.view.animation.CycleInterpolator; 
import android.view.animation.TranslateAnimation; 
import android.widget.EditText; 
/** 
 * 在焦点变化时和输入内容发生变化时均要判断是否显示右边clean图标 
 */ 
public class CleanableEditText extends EditText { 
  private Drawable mRightDrawable; 
  private boolean isHasFocus; 
   
  public CleanableEditText(Context context) { 
    super(context); 
    init(); 
  } 
  public CleanableEditText(Context context, AttributeSet attrs) { 
    super(context, attrs); 
    init(); 
  } 
 
  public CleanableEditText(Context context, AttributeSet attrs, int defStyle) { 
    super(context, attrs, defStyle); 
    init(); 
  } 
   
  private void init(){ 
    //getCompoundDrawables: 
    //Returns drawables for the left, top, right, and bottom borders. 
    Drawable [] drawables=this.getCompoundDrawables(); 
     
    //取得right位置的Drawable 
    //即我们在布局文件中设置的android:drawableRight 
    mRightDrawable=drawables[2];   
     
    //设置焦点变化的监听 
    this.setOnFocusChangeListener(new FocusChangeListenerImpl()); 
    //设置EditText文字变化的监听 
    this.addTextChangedListener(new TextWatcherImpl()); 
    //初始化时让右边clean图标不可见 
    setClearDrawableVisible(false); 
  } 
   
   
  /** 
   * 当手指抬起的位置在clean的图标的区域 
   * 我们将此视为进行清除操作 
   * getWidth():得到控件的宽度 
   * event.getX():抬起时的坐标(改坐标是相对于控件本身而言的) 
   * getTotalPaddingRight():clean的图标左边缘至控件右边缘的距离 
   * getPaddingRight():clean的图标右边缘至控件右边缘的距离 
   * 于是: 
   * getWidth() - getTotalPaddingRight()表示: 
   * 控件左边到clean的图标左边缘的区域 
   * getWidth() - getPaddingRight()表示: 
   * 控件左边到clean的图标右边缘的区域 
   * 所以这两者之间的区域刚好是clean的图标的区域 
   */ 
  @Override 
  public boolean onTouchEvent(MotionEvent event) { 
    switch (event.getAction()) { 
    case MotionEvent.ACTION_UP: 
       
      boolean isClean =(event.getX() > (getWidth() - getTotalPaddingRight()))&& 
               (event.getX() <(getWidth() - getPaddingRight())); 
      if (isClean) { 
        setText(""); 
      } 
      break; 
 
    default: 
      break; 
    } 
    return super.onTouchEvent(event); 
  } 
   
  private class FocusChangeListenerImpl implements OnFocusChangeListener{ 
    @Override 
    public void onFocusChange(View v, boolean hasFocus) { 
       isHasFocus=hasFocus; 
       if (isHasFocus) { 
         boolean isVisible=getText().toString().length()>=1; 
         setClearDrawableVisible(isVisible); 
      } else { 
         setClearDrawableVisible(false); 
      } 
    } 
     
  } 
   
  //当输入结束后判断是否显示右边clean的图标 
  private class TextWatcherImpl implements TextWatcher{ 
    @Override 
    public void afterTextChanged(Editable s) { 
       boolean isVisible=getText().toString().length()>=1; 
       setClearDrawableVisible(isVisible); 
    } 
 
    @Override 
    public void beforeTextChanged(CharSequence s, int start, int count,int after) { 
       
    } 
 
    @Override 
    public void onTextChanged(CharSequence s, int start, int before,int count) { 
       
    } 
     
  }   
   
  //隐藏或者显示右边clean的图标 
  protected void setClearDrawableVisible(boolean isVisible) { 
    Drawable rightDrawable; 
    if (isVisible) { 
      rightDrawable = mRightDrawable; 
    } else { 
      rightDrawable = null; 
    } 
    //使用代码设置该控件left, top, right, and bottom处的图标 
    setCompoundDrawables(getCompoundDrawables()[0],getCompoundDrawables()[1],  
               rightDrawable,getCompoundDrawables()[3]); 
  }  
 
  // 显示一个动画,以提示用户输入 
  public void setShakeAnimation() { 
    this.setAnimation(shakeAnimation(5)); 
  } 
 
  //CycleTimes动画重复的次数 
  public Animation shakeAnimation(int CycleTimes) { 
    Animation translateAnimation = new TranslateAnimation(0, 10, 0, 10); 
    translateAnimation.setInterpolator(new CycleInterpolator(CycleTimes)); 
    translateAnimation.setDuration(1000); 
    return translateAnimation; 
  } 
 
}