自定义View+随机数点击变化

CustomTitleView

public class CustomTitleView extends View {
/**
* 文本
*/
private String mTitleText;
/**
* 文本的颜色
*/
private int mTitleTextColor;
/**
* 文本的大小
*/
private int mTitleTextSize;

/**
* 绘制时控制文本绘制的范围
*/
private Rect mBound;
private Paint mPaint;

public CustomTitleView(Context context, AttributeSet attrs)
{
this(context, attrs, 0);
}

public CustomTitleView(Context context)
{
this(context, null);
}

/**
* 获得我自定义的样式属性
*
* @param context
* @param attrs
* @param defStyle
*/
public CustomTitleView(Context context, AttributeSet attrs, int defStyle)
{
super(context, attrs, defStyle);
/**
* 获得我们所定义的自定义样式属性
*/
TypedArray a = context.getTheme().obtainStyledAttributes(attrs, R.styleable.CustomTitleView, defStyle, 0);
int n = a.getIndexCount();
for (int i = 0; i < n; i++)
{
int attr = a.getIndex(i);
switch (attr)
{
case R.styleable.CustomTitleView_titleText:
mTitleText = a.getString(attr);
break;
case R.styleable.CustomTitleView_titleTextColor:
// 默认颜色设置为黑色
mTitleTextColor = a.getColor(attr, Color.BLACK);
break;
case R.styleable.CustomTitleView_titleTextSize:
// 默认设置为16sp，TypeValue也可以把sp转化为px
mTitleTextSize = a.getDimensionPixelSize(attr, (int) TypedValue.applyDimension(
TypedValue.COMPLEX_UNIT_SP, 16, getResources().getDisplayMetrics()));
break;

}

}
a.recycle();

/**
* 获得绘制文本的宽和高
*/
mPaint = new Paint();
mPaint.setTextSize(mTitleTextSize);
// mPaint.setColor(mTitleTextColor);
mBound = new Rect();
mPaint.getTextBounds(mTitleText, 0, mTitleText.length(), mBound);

}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
{
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}

@Override
protected void onDraw(Canvas canvas)
{
mPaint.setColor(Color.YELLOW);
canvas.drawRect(0, 0, getMeasuredWidth(), getMeasuredHeight(), mPaint);

mPaint.setColor(mTitleTextColor);
canvas.drawText(mTitleText, getWidth() / 2 - mBound.width() / 2, getHeight() / 2 + mBound.height() / 2, mPaint);
this.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View view) {
mTitleText = randomText();
postInvalidate();
}
});
}
private String randomText() {
Random random = new Random();
Set<Integer> set = new HashSet<Integer>();
while (set.size() < 4)
{
int randomInt = random.nextInt(10);
set.add(randomInt);
}
StringBuffer sb = new StringBuffer();
for (Integer i : set)
{
sb.append("" + i);
}

return sb.toString();
}
}
attrs.xml
 

<?xml version="1.0" encoding="utf-8"?>
<resources>

<attr name="titleText" format="string" />
<attr name="titleTextColor" format="color" />
<attr name="titleTextSize" format="dimension" />

<declare-styleable name="CustomTitleView">
<attr name="titleText" />
<attr name="titleTextColor" />
<attr name="titleTextSize" />
</declare-styleable>

</resources>

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:custom="http://schemas.android.com/apk/res-auto"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"

tools:context="com.example.demo12306.MainActivity">
<com.example.demo12306.CustomTitleViewandroid:id="@+id/tangao"
android:layout_width="match_parent"
android:layout_height="match_parent"
custom:titleText="3712"
custom:titleTextColor="#ff0000"
custom:titleTextSize="40sp" />

</RelativeLayout>