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Android如何自定義EditText下劃線？

更新時間：2016年01月14日 11:54:30 作者：OneAPM

Android如何自定義EditText下劃線？本文教大家利用Android實現(xiàn)自定義的EditText下劃線，感興趣的小伙伴們可以參考一下

曾經(jīng)做過一個項目，其中登錄界面的交互令人印象深刻。交互設(shè)計師給出了一個非常作的設(shè)計，要求做出包含根據(jù)情況可變色的下劃線，左側(cè)有可變圖標(biāo)，右側(cè)有可變刪除標(biāo)志的輸入框，如圖

記錄制作過程：

第一版本

public class LineEditText extends EditText {

private Paint mPaint;
private int color;
public static final int STATUS_FOCUSED = 1;
public static final int STATUS_UNFOCUSED = 2;
public static final int STATUS_ERROR = 3;
private int status = 2;
private Drawable del_btn;
private Drawable del_btn_down;
private int focusedDrawableId = R.drawable.user_select;// 默認(rèn)的
private int unfocusedDrawableId = R.drawable.user;
private int errorDrawableId = R.drawable.user_error;
Drawable left = null;
private Context mContext;
public LineEditText(Context context) {

 super(context);
 mContext = context;
 init();
}
public LineEditText(Context context, AttributeSet attrs) {

 super(context, attrs);
 mContext = context;
 init();

}
public LineEditText(Context context, AttributeSet attrs, int defStryle) {

 super(context, attrs, defStryle);
 mContext = context;
 TypedArray a = context.obtainStyledAttributes(attrs,
   R.styleable.lineEdittext, defStryle, 0);
 focusedDrawableId = a.getResourceId(
   R.styleable.lineEdittext_drawableFocus, R.drawable.user_select);
 unfocusedDrawableId = a.getResourceId(
   R.styleable.lineEdittext_drawableUnFocus, R.drawable.user);
 errorDrawableId = a.getResourceId(
   R.styleable.lineEdittext_drawableError, R.drawable.user_error);
 a.recycle();
 init();
}
/** * 2014/7/31 * * @author Aimee.ZHANG */

private void init() {
 mPaint = new Paint();
 // mPaint.setStyle(Paint.Style.FILL);
 mPaint.setStrokeWidth(3.0f);
 color = Color.parseColor("#bfbfbf");
 setStatus(status);
 del_btn = mContext.getResources().getDrawable(R.drawable.del_but_bg);
 del_btn_down = mContext.getResources().getDrawable(R.drawable.del_but_bg_down);
 addTextChangedListener(new TextWatcher() {

  @Override
  public void onTextChanged(CharSequence arg0, int arg1, int arg2,
    int arg3) {
  }

  @Override
  public void beforeTextChanged(CharSequence arg0, int arg1,
    int arg2, int arg3) {
  }

  @Override
  public void afterTextChanged(Editable arg0) {
   setDrawable();
  }
 });
 setDrawable();
}

@Override
protected void onDraw(Canvas canvas) {
 super.onDraw(canvas);
 mPaint.setColor(color);
 canvas.drawLine(0, this.getHeight() - 1, this.getWidth(),
   this.getHeight() - 1, mPaint);
}

// 刪除圖片
private void setDrawable() {
 if (length() < 1) {
  setCompoundDrawablesWithIntrinsicBounds(left, null, del_btn, null);
 } else {
  setCompoundDrawablesWithIntrinsicBounds(left, null, del_btn_down,null);
 }
}

// 處理刪除事件
@Override
public boolean onTouchEvent(MotionEvent event) {
 if (del_btn_down != null && event.getAction() == MotionEvent.ACTION_UP) {
  int eventX = (int) event.getRawX();
  int eventY = (int) event.getRawY();
  Log.e("eventXY", "eventX = " + eventX + "; eventY = " + eventY); 
  Rect rect = new Rect();
  getGlobalVisibleRect(rect);
  rect.left = rect.right - 50;
  if (rect.contains(eventX, eventY))
  setText("");
 }
 return super.onTouchEvent(event);
}

public void setStatus(int status) {
 this.status = status;


 if (status == STATUS_ERROR) {
  try {
   left = getResources().getDrawable(errorDrawableId);
  } catch (NotFoundException e) {
   e.printStackTrace();
  }
  setColor(Color.parseColor("#f57272"));
 } else if (status == STATUS_FOCUSED) {
  try {
   left = getResources().getDrawable(focusedDrawableId);
  } catch (NotFoundException e) {
   e.printStackTrace();
  }
  setColor(Color.parseColor("#5e99f3"));
 } else {
  try {
   left = getResources().getDrawable(unfocusedDrawableId);
  } catch (NotFoundException e) {
   e.printStackTrace();
  }
  setColor(Color.parseColor("#bfbfbf"));
 }
 if (left != null) {
// left.setBounds(0, 0, 30, 40);

// this.setCompoundDrawables(left, null, null, null);

  setCompoundDrawablesWithIntrinsicBounds(left,null,del_btn,null);
 }
 postInvalidate();
}

public void setLeftDrawable(int focusedDrawableId, int unfocusedDrawableId,
  int errorDrawableId) {
 this.focusedDrawableId = focusedDrawableId;
 this.unfocusedDrawableId = unfocusedDrawableId;
 this.errorDrawableId = errorDrawableId;
 setStatus(status);
}

@Override
protected void onFocusChanged(boolean focused, int direction,
  Rect previouslyFocusedRect) {
 super.onFocusChanged(focused, direction, previouslyFocusedRect);
 if (focused) {
  setStatus(STATUS_FOCUSED);
 } else {
  setStatus(STATUS_UNFOCUSED);
 }
}

@Override
protected void finalize() throws Throwable {
 super.finalize();
};

public void setColor(int color) {
 this.color = color;
 this.setTextColor(color);
 invalidate();
}
}

效果圖：

代碼解釋：

變量名 STATUS_FOCUSED,STATUS_UNFOCUSED,STATUS_ERROR 標(biāo)示了三種狀態(tài)，選中狀況為藍色，未選中狀態(tài)為灰色，錯誤狀態(tài)為紅色。 focusedDrawableId unfocusedDrawableId errorDrawableId 存放三種狀態(tài)的圖片，放置于最左側(cè)。

canvas.drawLine(0, this.getHeight() - 1, this.getWidth(),this.getHeight() - 1, mPaint); //畫editText 最下方的線 setCompoundDrawablesWithIntrinsicBounds(left, null, del_btn, null); //放置左邊的和右邊的圖片（左，上，右，下）相當(dāng)于 android:drawableLeft="" android:drawableRight=""

1、onTouchEvent 當(dāng)手機點擊時，第一個先執(zhí)行的函數(shù)，當(dāng)點擊右側(cè)刪除圖標(biāo)是清空 edittext
2、setStatus 根據(jù)不同的狀態(tài)，左邊的圖片不一樣
存在的問題：這版本雖然基本功能已經(jīng)實現(xiàn)，但是不符合需求，設(shè)計中要求文本框中無文字時，右側(cè)刪除按鈕不顯示，不點擊刪除按鈕，刪除按鈕要保持灰色，點擊時才可以變藍色。

因此有了第二個版本

public class LineEditText extends EditText implements TextWatcher, <br /> OnFocusChangeListener{

private Paint mPaint;
private int color;
public static final int STATUS_FOCUSED = 1;
public static final int STATUS_UNFOCUSED = 2;
public static final int STATUS_ERROR = 3;
private int status = 2;
private Drawable del_btn;
private Drawable del_btn_down;
private int focusedDrawableId = R.drawable.user_select;// 默認(rèn)的
private int unfocusedDrawableId = R.drawable.user;
private int errorDrawableId = R.drawable.user_error;
Drawable left = null;
private Context mContext;
/** 
 * 是否獲取焦點，默認(rèn)沒有焦點 
 */ 
private boolean hasFocus = false; 
/** 
 * 手指抬起時的X坐標(biāo) 
 */ 
private int xUp = 0; 

public LineEditText(Context context) {
 super(context);
 mContext = context;
 init();
}

public LineEditText(Context context, AttributeSet attrs) {
 super(context, attrs);
 mContext = context;
 init();

}

public LineEditText(Context context, AttributeSet attrs, int defStryle) {
 super(context, attrs, defStryle);
 mContext = context;
 TypedArray a = context.obtainStyledAttributes(attrs,
   R.styleable.lineEdittext, defStryle, 0);
 focusedDrawableId = a.getResourceId(
   R.styleable.lineEdittext_drawableFocus, R.drawable.user_select);
 unfocusedDrawableId = a.getResourceId(
   R.styleable.lineEdittext_drawableUnFocus, R.drawable.user);
 errorDrawableId = a.getResourceId(
   R.styleable.lineEdittext_drawableError, R.drawable.user_error);
 a.recycle();
 init();
}

/**
 * 2014/7/31
 * 
 * @author Aimee.ZHANG
 */
private void init() {
 mPaint = new Paint();
 // mPaint.setStyle(Paint.Style.FILL);
 mPaint.setStrokeWidth(3.0f);
 color = Color.parseColor("#bfbfbf");
 setStatus(status);
 del_btn = mContext.getResources().getDrawable(R.drawable.del_but_bg);
 del_btn_down = mContext.getResources().getDrawable(R.drawable.del_but_bg_down);
 addListeners();
 setCompoundDrawablesWithIntrinsicBounds(left, null, null, null);
}

@Override
protected void onDraw(Canvas canvas) {
 super.onDraw(canvas);
 mPaint.setColor(color);
 canvas.drawLine(0, this.getHeight() - 1, this.getWidth(),
   this.getHeight() - 1, mPaint);
}

// 刪除圖片
// private void setDrawable() { // if (length() < 1) { // setCompoundDrawablesWithIntrinsicBounds(left, null, null, null); // } else { // setCompoundDrawablesWithIntrinsicBounds(left, null, del_btn,null); // } // }

// 處理刪除事件
@Override
public boolean onTouchEvent(MotionEvent event) {
 if (del_btn != null && event.getAction() == MotionEvent.ACTION_UP) {
  // 獲取點擊時手指抬起的X坐標(biāo) 
  xUp = (int) event.getX(); 
  Log.e("xUp", xUp+""); 
  /*Rect rect = new Rect();
  getGlobalVisibleRect(rect);
  rect.left = rect.right - 50;*/
   // 當(dāng)點擊的坐標(biāo)到當(dāng)前輸入框右側(cè)的距離小于等于 getCompoundPaddingRight() 的距離時，則認(rèn)為是點擊了刪除圖標(biāo) 
  if ((getWidth() - xUp) <= getCompoundPaddingRight()) { 
   if (!TextUtils.isEmpty(getText().toString())) {
    setText(""); 
   } 
  }
 }else if(del_btn != null && event.getAction() == MotionEvent.ACTION_DOWN && getText().length()!=0){
  setCompoundDrawablesWithIntrinsicBounds(left,null,del_btn_down,null);
 }else if(getText().length()!=0){
  setCompoundDrawablesWithIntrinsicBounds(left,null,del_btn,null);
 }
 return super.onTouchEvent(event);
}

public void setStatus(int status) {
 this.status = status;


 if (status == STATUS_ERROR) {
  try {
   left = getResources().getDrawable(errorDrawableId);
  } catch (NotFoundException e) {
   e.printStackTrace();
  }
  setColor(Color.parseColor("#f57272"));
 } else if (status == STATUS_FOCUSED) {
  try {
   left = getResources().getDrawable(focusedDrawableId);
  } catch (NotFoundException e) {
   e.printStackTrace();
  }
  setColor(Color.parseColor("#5e99f3"));
 } else {
  try {
   left = getResources().getDrawable(unfocusedDrawableId);
  } catch (NotFoundException e) {
   e.printStackTrace();
  }
  setColor(Color.parseColor("#bfbfbf"));
 }
 if (left != null) {
// left.setBounds(0, 0, 30, 40); // this.setCompoundDrawables(left, null, null, null); setCompoundDrawablesWithIntrinsicBounds(left,null,null,null); } postInvalidate(); }

public void setLeftDrawable(int focusedDrawableId, int unfocusedDrawableId,
  int errorDrawableId) {
 this.focusedDrawableId = focusedDrawableId;
 this.unfocusedDrawableId = unfocusedDrawableId;
 this.errorDrawableId = errorDrawableId;
 setStatus(status);
}
 private void addListeners() { 
  try { 
   setOnFocusChangeListener(this); 
   addTextChangedListener(this); 
  } catch (Exception e) { 
   e.printStackTrace(); 
  } 
 } 
@Override
protected void onFocusChanged(boolean focused, int direction,
  Rect previouslyFocusedRect) {
 super.onFocusChanged(focused, direction, previouslyFocusedRect);
 this.hasFocus=focused;
 if (focused) {
  setStatus(STATUS_FOCUSED);
 } else {
  setStatus(STATUS_UNFOCUSED);
  setCompoundDrawablesWithIntrinsicBounds(left,null,null,null);
 }
}

@Override
protected void finalize() throws Throwable {
 super.finalize();
};

public void setColor(int color) {
 this.color = color;
 this.setTextColor(color);
 invalidate();
}



@Override
public void afterTextChanged(Editable arg0) {
 // TODO Auto-generated method stub
 postInvalidate();
}

@Override
public void beforeTextChanged(CharSequence arg0, int arg1, int arg2,
  int arg3) {
 // TODO Auto-generated method stub
  if (TextUtils.isEmpty(arg0)) { 
   // 如果為空，則不顯示刪除圖標(biāo) 
   setCompoundDrawablesWithIntrinsicBounds(left, null, null, null); 
  } else { 
   // 如果非空，則要顯示刪除圖標(biāo) 
   setCompoundDrawablesWithIntrinsicBounds(left, null, del_btn, null); 
  } 
}
@Override
 public void onTextChanged(CharSequence s, int start, int before, int after) { 
 if (hasFocus) { 
  if (TextUtils.isEmpty(s)) { 
   // 如果為空，則不顯示刪除圖標(biāo) 
   setCompoundDrawablesWithIntrinsicBounds(left, null, null, null); 
  } else { 
   // 如果非空，則要顯示刪除圖標(biāo) 
   setCompoundDrawablesWithIntrinsicBounds(left, null, del_btn, null); 
  } 
 } 
}

@Override
public void onFocusChange(View arg0, boolean arg1) {
 // TODO Auto-generated method stub
 try { 
  this.hasFocus = arg1; 
 } catch (Exception e) { 
  e.printStackTrace(); 
 } 
} 
}

比較關(guān)鍵的方法是：onTouchEvent

當(dāng)進入界面，點擊輸入框，要判斷輸入框中是否已有文字，如果有則顯示灰色的刪除按鈕，如果沒有則不顯示，如果點擊了刪除按鈕，刪除按鈕變藍色

存在的問題：這個版本依舊存在問題，就是輸入長度超過輸入框，所畫的線不會延伸，如圖

解決方法：

@Override

protected void onDraw(Canvas canvas) {
 super.onDraw(canvas);
 mPaint.setColor(color);
 int x=this.getScrollX();
 int w=this.getMeasuredWidth();
 canvas.drawLine(0, this.getHeight() - 1, w+x,
   this.getHeight() - 1, mPaint);
}

w：獲取控件長度

X：延伸后的長度

最終效果：