自定義帶刪除按鈕的EditText

原理：在EditText右邊添加一個刪除圖片，當文本長度大於0的時候，顯示圖片，點擊圖片所在區域，將EditText的文本置爲空。

package com.example.conponent;

import com.example.R;

import android.content.Context;
import android.graphics.Rect;
import android.graphics.drawable.Drawable;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.widget.EditText;

public class ClearableEditText extends EditText {
	
	private Context mContext;
	private Drawable innerImg;

	public ClearableEditText(Context context) {
		super(context);
		this.mContext = context;
		init();
	}

	public ClearableEditText(Context context, AttributeSet attrs) {
		super(context, attrs);
		this.mContext = context;
		init();
	}

	public ClearableEditText(Context context, AttributeSet attrs, int defStyleAttr) {
		super(context, attrs, defStyleAttr);
		this.mContext = context;
		init();
	}
	
	private void init()
	{
		innerImg = mContext.getResources().getDrawable(R.drawable.delete_gray);
		addTextChangedListener(new TextWatcher() {
			
			@Override
			public void onTextChanged(CharSequence s, int start, int before, int count) {
				
			}
			
			@Override
			public void beforeTextChanged(CharSequence s, int start, int count, int after) {
				
			}
			
			@Override
			public void afterTextChanged(Editable s) {
				setDrawable();
			}
		});
		
		setDrawable();
	}
	
	private void setDrawable()
	{
		if(length() < 1)
			setCompoundDrawablesWithIntrinsicBounds(null, null, null, null);
		else
			setCompoundDrawablesWithIntrinsicBounds(null, null, innerImg, null);
	}
	
	@Override
	public boolean onTouchEvent(MotionEvent event) {
		
		if(innerImg != null && event.getAction() == MotionEvent.ACTION_UP);
		int x = (int) event.getRawX();
		int y = (int) event.getRawY();
		
		Rect rect = new Rect();
		getGlobalVisibleRect(rect);
		rect.left = rect.right - 100;
		
		if(rect.contains(x, y))
			setText("");
		
		return super.onTouchEvent(event);
	}
	
	@Override
	protected void finalize() throws Throwable {
		super.finalize();
	}
}