暴露您view中所有影响可见外观的属性或者行为。
•通过XML添加和设置样式
•通过元素的属性来控制其外观和行为，支持和重要事件交流的事件监听器
详细步骤见：Android 自定义View步骤
效果图展示：
支持的样式
可以通过XML定义影响外边和行为的属性如下
边框圆角值，边框颜色，分割线颜色，边框宽度，密码长度，密码大小，密码颜色
<declare-styleable name="PasswordInputView"> <attr name="borderWidth" format="dimension"/> <attr name="borderColor" format="color"/> <attr name="borderRadius" format="dimension"/> <attr name="passwordLength" format="integer"/> <attr name="passwordWidth" format="dimension"/> <attr name="passwordColor" format="color"/> <attr name="passwordRadius" format="dimension"/> </declare-styleable>
同时支持原来EditText功能，可以获得数据值，数字键盘设置等
绘制逻辑的主要代码
protected void onDraw(Canvas canvas) {
int width = getWidth();
int height = getHeight();
// 外边框
RectF rect = new RectF(0, 0, width, height);
borderPaint.setColor(borderColor);
canvas.drawRoundRect(rect, borderRadius, borderRadius, borderPaint);
// 内容区
RectF rectIn = new RectF(rect.left + defaultContMargin, rect.top + defaultContMargin,
rect.right - defaultContMargin, rect.bottom - defaultContMargin);
borderPaint.setColor(Color.WHITE);
canvas.drawRoundRect(rectIn, borderRadius, borderRadius, borderPaint);
// 分割线
borderPaint.setColor(borderColor);
borderPaint.setStrokeWidth(defaultSplitLineWidth);
for (int i = 1; i < passwordLength; i++) {
float x = width * i / passwordLength;
canvas.drawLine(x, 0, x, height, borderPaint);
}
// 密码
float cx, cy = height/ 2;
float half = width / passwordLength / 2;
for(int i = 0; i < textLength; i++) {
cx = width * i / passwordLength + half;
canvas.drawCircle(cx, cy, passwordWidth, passwordPaint);
}
}