java.lang.NullPointerException
Exception?details?are?logged?in?Window?>?Show?View?>?Error?Log

java.lang.NullPointerException
????at?com.example.weixin.ChangeColorIconWithText.onDraw(ChangeColorIconWithText.java:85)
????at?android.view.View.draw(View.java:14465)
????at?android.view.View.draw(View.java:14350)
????at?android.view.ViewGroup.drawChild(ViewGroup.java:3103)
????at?android.view.ViewGroup.dispatchDraw(ViewGroup.java:2940)
????at?android.view.View.draw(View.java:14468)
????at?android.view.View.draw(View.java:14350)
????at?android.view.ViewGroup.drawChild(ViewGroup.java:3103)
????at?android.view.ViewGroup.dispatchDraw(ViewGroup.java:2940)
????at?android.view.View.draw(View.java:14348)
????at?android.view.ViewGroup.drawChild(ViewGroup.java:3103)
????at?android.view.ViewGroup.dispatchDraw(ViewGroup.java:2940)
????at?android.view.View.draw(View.java:14348)
????at?android.view.ViewGroup.drawChild(ViewGroup.java:3103)
????at?android.view.ViewGroup.dispatchDraw(ViewGroup.java:2940)
????at?android.view.View.draw(View.java:14468)
????at?android.view.View.draw(View.java:14350)
????at?android.view.ViewGroup.drawChild(ViewGroup.java:3103)
????at?android.view.ViewGroup.dispatchDraw(ViewGroup.java:2940)
????at?android.view.View.draw(View.java:14468)
????下面是代碼：
????package?com.example.weixin;

import?android.content.Context;
import?android.content.res.TypedArray;
import?android.graphics.Bitmap;
import?android.graphics.Canvas;
import?android.graphics.Paint;
import?android.graphics.Rect;
import?android.graphics.drawable.BitmapDrawable;
import?android.util.AttributeSet;
import?android.util.TypedValue;
import?android.view.View;

public?class?ChangeColorIconWithText?extends?View?{
	private?int?mColor?=?0xFF45C01A;
	private?Bitmap?mIconBitmap;
	private?String?mTextString?=?"微信";
	private?int?mTextSize?=?(int)?TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP,?12,?
			getResources().getDisplayMetrics());
	
	private?Canvas?mCanvas;
	private?Bitmap?mBitmap;
	private?Paint?mPaint;
	
	private?float?mAlpha;

	private?Rect?mIconRect;
	private?Rect?mTextBound;
	private?Paint?mTextPaint;
	
	public?ChangeColorIconWithText(Context?context,?AttributeSet?attrs,
			int?defStyleAttr)?{
		super(context,?attrs,?defStyleAttr);
		TypedArray?a?=?context.obtainStyledAttributes(attrs,?
				R.styleable.ChangeColorIconWithText);
		int?n?=?a.getIndexCount();
		for?(int?i?=?0;?i?<?n;?i++)?{
			int?attr?=?a.getIndex(i);
			switch?(attr)?{
			case?R.styleable.ChangeColorIconWithText_icon1:
				BitmapDrawable?drawable?=?(BitmapDrawable)?a.getDrawable(attr);
				mIconBitmap?=?drawable.getBitmap();
				break;

			case?R.styleable.ChangeColorIconWithText_color:
				mColor?=?a.getColor(attr,?0xFF45C01A);
				break;
			case?R.styleable.ChangeColorIconWithText_text:
				mTextString?=?a.getString(attr);
				break;
			case?R.styleable.ChangeColorIconWithText_text_size:
				mTextSize?=?(int)?a.getDimension(attr,?
						TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP,?
								12,?getResources().getDisplayMetrics()));
				break;
			}
		}
		a.recycle();
		
		mTextBound?=?new?Rect();
		mTextPaint?=?new?Paint();
		mTextPaint.setTextSize(mTextSize);
		mTextPaint.setColor(0Xff555555);	
		mTextPaint.getTextBounds(mTextString,?0,?mTextString.length(),?mTextBound);
	}
	
	@Override
	protected?void?onMeasure(int?widthMeasureSpec,?int?heightMeasureSpec)?{
		//?TODO?Auto-generated?method?stub
		super.onMeasure(widthMeasureSpec,?heightMeasureSpec);
		int?iconWidth?=?Math.min(getMeasuredWidth()-
				getPaddingLeft()-getPaddingRight(),?
				getMeasuredHeight()-getPaddingTop()-
				getPaddingBottom()-?mTextBound.height());
		int?left?=?getMeasuredWidth()/2?-?iconWidth/2;
		int?top?=?(getMeasuredHeight()-mTextBound.height())/2
				-iconWidth/2;
		mIconRect?=?new?Rect(left,?top,?left+iconWidth,?
				top+iconWidth);
	}
	
	protected?void?onDraw(Canvas?canvas)?{
		//?TODO?Auto-generated?method?stub
		super.onDraw(canvas);
		mCanvas.drawBitmap(mIconBitmap,?mIconRect,?mIconRect,?null);
		
		
	}

	public?ChangeColorIconWithText(Context?context,?AttributeSet?attrs)?{
		this(context,attrs,0);
		//?TODO?Auto-generated?constructor?stub
	}

	public?ChangeColorIconWithText(Context?context)?{
		this(context,null);
		//?TODO?Auto-generated?constructor?stub
	}

}