工作中經常會用到圓角的按鈕，另外點擊還需要有按下的效果。機智的你是否已經厭煩了有時甚至為了改變顏色而不停的寫drawable文件。于是我想寫一個自定義的View實現(xiàn)這個效果以后項目中也能直接用上。廢話不多說直接上源碼

public class RoundClickButton extends View {    
private static final String TAG = RoundClickButton.class.getSimpleName();    
private static final int DEFAULT_TEXT_PADDING = 40;    
private Paint paint;    
//平常時的顏色    
private int normalColor;    
//點擊后的顏色    
private int pressedColor;   
//圓角的半徑   
private float roundRadius;    
//按鈕顯示的內容    
private String buttonText;    
//設置字體大小    
private int buttonTextSize;    
private float buttonWidth;    
private float buttonHeight;    
private float buttonPadding;    

public RoundClickButton(Context context) {        
super(context);    
}    

public RoundClickButton(Context context, AttributeSet attrs) {       
 super(context, attrs);        
TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.RoundClickButton);        
normalColor = array.getColor(R.styleable.RoundClickButton_buttonNormalColor, Color.WHITE);        
pressedColor = array.getColor(R.styleable.RoundClickButton_buttonPressedColor, Color.RED);        
roundRadius = array.getDimension(R.styleable.RoundClickButton_buttonRoundRadius, 5.0f);        
buttonText = array.getString(R.styleable.RoundClickButton_buttonText);        
buttonWidth = array.getDimension(R.styleable.RoundClickButton_buttonWidth, 0);        
buttonHeight = array.getDimension(R.styleable.RoundClickButton_buttonHeight, 0);        
buttonTextSize = array.getInt(R.styleable.RoundClickButton_buttonTextSize, 16);        
buttonPadding = array.getDimension(R.styleable.RoundClickButton_buttonPadding, 5);        
paint = new Paint();        
paint.setColor(normalColor);        
paint.setAntiAlias(true);        
paint.setStyle(Paint.Style.FILL);        
paint.setStrokeWidth(2);        
paint.setTextSize(TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, buttonTextSize, context.getResources().getDisplayMetrics()));        
textView = new TextView(context);        
textView.setTextSize(TypedValue.COMPLEX_UNIT_SP, buttonTextSize);        
buttonWidth = textView.getPaint().measureText(buttonText) + DEFAULT_TEXT_PADDING * 2;        
Log.e(TAG, "w = " + buttonWidth);    }    

TextView textView;    
@Override    
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {        
super.onMeasure(widthMeasureSpec, heightMeasureSpec);        
Paint.FontMetrics fm = paint.getFontMetrics();        
buttonHeight = (float) (Math.abs(Math.ceil(fm.descent + fm.top)) + buttonPadding * 2);        
buttonHeight = buttonHeight > DEFAULT_TEXT_PADDING ? buttonHeight : DEFAULT_TEXT_PADDING;        
if (MeasureSpec.getMode(widthMeasureSpec) == MeasureSpec.EXACTLY)            
buttonWidth = MeasureSpec.getSize(widthMeasureSpec);        
if (MeasureSpec.getMode(heightMeasureSpec) == MeasureSpec.EXACTLY)            
buttonHeight = MeasureSpec.getSize(heightMeasureSpec);        
setMeasuredDimension((int) buttonWidth, (int) buttonHeight);    }    

@Override    
protected void onDraw(Canvas canvas) {        
super.onDraw(canvas);        
RectF rectF = new RectF(0, 0, buttonWidth, buttonHeight);        
canvas.drawRoundRect(rectF, roundRadius, roundRadius, paint);        
Paint.FontMetricsInt fontMetricsInt = paint.getFontMetricsInt();        
int baseLine = (int) ((rectF.bottom + rectF.top - fontMetricsInt.bottom - fontMetricsInt.top) / 2);        paint.setTextAlign(Paint.Align.CENTER);        
paint.setColor(Color.WHITE);        
canvas.drawText(buttonText, rectF.centerX(), baseLine, paint);    }    

@Override    
public boolean onTouchEvent(MotionEvent event) {        
switch (event.getAction()) {            
case MotionEvent.ACTION_DOWN:                
paint.setColor(pressedColor);                
postInvalidate();                
break;            
case MotionEvent.ACTION_MOVE:                
break;            
case MotionEvent.ACTION_UP:                
paint.setColor(normalColor);                
postInvalidate();                
break;        
}        
return super.onTouchEvent(event);    
}
}