Android View教程之自定义验证码输入框效果

/** * 验证码输入框,重写EditText的绘制方法实现。 * @author RAE */public class CodeEditText extends AppCompatEditText {  // 验证码文本颜色 private int mTextColor; // 输入的最大长度 private int mMaxLength = 4; // 边框宽度 private int mStrokeWidth; // 边框高度 private int mStrokeHeight; // 边框之间的距离 private int mStrokePadding = 20; // 用矩形来保存方框的位置、大小信息 private final Rect mRect = new Rect(); // 方框的背景 private Drawable mStrokeDrawable; /** * 构造方法 * */ public CodeEditText(Context context, AttributeSet attrs) { super(context, attrs); TypedArray typedArray = context.obtainStyledAttributes(attrs, R.styleable.CodeEditText); int indexCount = typedArray.getIndexCount(); for (int i = 0; i < indexCount; i++) {  int index = typedArray.getIndex(i);  if (index == R.styleable.CodeEditText_strokeHeight) {  this.mStrokeHeight = (int) typedArray.getDimension(index, 60);  } else if (index == R.styleable.CodeEditText_strokeWidth) {  this.mStrokeWidth = (int) typedArray.getDimension(index, 60);  } else if (index == R.styleable.CodeEditText_strokePadding) {  this.mStrokePadding = (int) typedArray.getDimension(index, 20);  } else if (index == R.styleable.CodeEditText_strokeBackground) {  this.mStrokeDrawable = typedArray.getDrawable(index);  } else if (index == R.styleable.CodeEditText_strokeLength) {  this.mMaxLength = typedArray.getInteger(index, 4);  } } typedArray.recycle(); if (mStrokeDrawable == null) {  throw new NullPointerException("stroke drawable not allowed to be null!"); } setMaxLength(mMaxLength); setLongClickable(false); // 去掉背景颜色 setBackgroundColor(Color.TRANSPARENT); // 不显示光标 setCursorVisible(false); } @Override public boolean onTextContextMenuItem(int id) { return false; } /** * 设置最大长度 */ private void setMaxLength(int maxLength) { if (maxLength >= 0) {  setFilters(new InputFilter[]{new InputFilter.LengthFilter(maxLength)}); } else {  setFilters(new InputFilter[0]); } }}

 @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); // 当前输入框的宽高信息 int width = getMeasuredWidth(); int height = getMeasuredHeight(); int widthMode = MeasureSpec.getMode(widthMeasureSpec); int heightMode = MeasureSpec.getMode(heightMeasureSpec); // 判断高度是否小于推荐高度 if (height < mStrokeHeight) {  height = mStrokeHeight; } // 输入框宽度 = 边框宽度 * 数量 + 边框间距 *(数量-1) int recommendWidth = mStrokeWidth * mMaxLength + mStrokePadding * (mMaxLength - 1); // 判断宽度是否小于推荐宽度 if (width < recommendWidth) {  width = recommendWidth; } widthMeasureSpec = MeasureSpec.makeMeasureSpec(width, widthMode); heightMeasureSpec = MeasureSpec.makeMeasureSpec(height, heightMode); // 设置测量布局 setMeasuredDimension(widthMeasureSpec, heightMeasureSpec); }

 @Override protected void onDraw(Canvas canvas) {  // 在画支持设置文本颜色，把系统化的文本透明掉，相当于覆盖  mTextColor = getCurrentTextColor();  setTextColor(Color.TRANSPARENT);  // 系统画的方法  super.onDraw(canvas);  // 重新设置文本颜色  setTextColor(mTextColor);  // 重绘背景颜色  drawStrokeBackground(canvas);  // 重绘文本  drawText(canvas); }

 /**  * 绘制方框  */ private void drawStrokeBackground(Canvas canvas) {  // 下面绘制方框背景颜色  // 确定反馈位置  mRect.left = 0;  mRect.top = 0;  mRect.right = mStrokeWidth;  mRect.bottom = mStrokeHeight;  int count = canvas.getSaveCount(); // 当前画布保存的状态  canvas.save(); // 保存画布  for (int i = 0; i < mMaxLength; i++) {   mStrokeDrawable.setBounds(mRect); // 设置位置   mStrokeDrawable.setState(new int[]{android.R.attr.state_enabled}); // 设置图像状态   mStrokeDrawable.draw(canvas); // 画到画布上   // 确定下一个方框的位置   float dx = mRect.right + mStrokePadding; // X坐标位置   // 保存画布   canvas.save();   // [注意细节] 移动画布到下一个位置   canvas.translate(dx, 0);  }  // [注意细节] 把画布还原到画反馈之前的状态，这样就还原到最初位置了  canvas.restoreToCount(count);  // 画布归位  canvas.translate(0, 0);  // 下面绘制高亮状态的边框  // 当前高亮的索引  int activatedIndex = Math.max(0, getEditableText().length());  mRect.left = mStrokeWidth * activatedIndex + mStrokePadding * activatedIndex;  mRect.right = mRect.left + mStrokeWidth;  mStrokeDrawable.setState(new int[]{android.R.attr.state_focused});  mStrokeDrawable.setBounds(mRect);  mStrokeDrawable.draw(canvas); }

 /**  * 重绘文本  */ private void drawText(Canvas canvas) {  int count = canvas.getSaveCount();  canvas.translate(0, 0);  int length = getEditableText().length();  for (int i = 0; i < length; i++) {   String text = String.valueOf(getEditableText().charAt(i));   TextPaint textPaint = getPaint();   textPaint.setColor(mTextColor);   // 获取文本大小   textPaint.getTextBounds(text, 0, 1, mRect);   // 计算(x,y) 坐标   int x = mStrokeWidth / 2 + (mStrokeWidth + mStrokePadding) * i - (mRect.centerX());   int y = canvas.getHeight() / 2 + mRect.height() / 2;   canvas.drawText(text, x, y, textPaint);  }  canvas.restoreToCount(count); }

 @Override protected void onTextChanged(CharSequence text, int start,         int lengthBefore, int lengthAfter) {  super.onTextChanged(text, start, lengthBefore, lengthAfter);  // 当前文本长度  int textLength = getEditableText().length();  if (textLength == mMaxLength) {   hideSoftInput();   if (mOnInputFinishListener != null) {    mOnInputFinishListener.onTextFinish(getEditableText().toString(), mMaxLength);   }  } }