Android 自定义输入支付密码的软键盘
有项目需求需要做一个密码锁功能，还有自己的软键盘，类似与支付宝那种，这里是整理的资料，大家可以看下，如有错误，欢迎留言指正
需求：要实现类似支付宝的输入支付密码的功能，效果图如下：
软键盘效果图
使用 android.inputmethodservice.KeyboardView 这个类自定义软键盘
软键盘的实现
1. 自定义只输入数字的软键盘 PasswordKeyboardView 类，继承自 android.inputmethodservice.KeyboardView
/** * 输入数字密码的键盘布局控件。 */public class PasswordKeyboardView extends KeyboardView implements android.inputmethodservice.KeyboardView.OnKeyboardActionListener { // 用于区分左下角空白的按键 private static final int KEYCODE_EMPTY = -10; private int mDeleteBackgroundColor; private Rect mDeleteDrawRect; private Drawable mDeleteDrawable; private IOnKeyboardListener mOnKeyboardListener; public PasswordKeyboardView(Context context, AttributeSet attrs) { super(context, attrs); init(context, attrs, 0); } public PasswordKeyboardView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); init(context, attrs, defStyleAttr); } private void init(Context context, AttributeSet attrs, int defStyleAttr) { TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.PasswordKeyboardView, defStyleAttr, 0); mDeleteDrawable = a.getDrawable( R.styleable.PasswordKeyboardView_pkvDeleteDrawable); mDeleteBackgroundColor = a.getColor( R.styleable.PasswordKeyboardView_pkvDeleteBackgroundColor, Color.TRANSPARENT); a.recycle(); // 设置软键盘按键的布局 Keyboard keyboard = new Keyboard(context, R.xml.keyboard_number_password); setKeyboard(keyboard); setEnabled(true); setPreviewEnabled(false); setOnKeyboardActionListener(this); } @Override public void onDraw(Canvas canvas) { super.onDraw(canvas); // 遍历所有的按键 List<Keyboard.Key> keys = getKeyboard().getKeys(); for (Keyboard.Key key : keys) { // 如果是左下角空白的按键，重画按键的背景 if (key.codes[0] == KEYCODE_EMPTY) { drawKeyBackground(key, canvas, mDeleteBackgroundColor); } // 如果是右下角的删除按键，重画背景，并且绘制删除的图标 else if (key.codes[0] == Keyboard.KEYCODE_DELETE) { drawKeyBackground(key, canvas, mDeleteBackgroundColor); drawDeleteButton(key, canvas); } } } // 绘制按键的背景 private void drawKeyBackground(Keyboard.Key key, Canvas canvas, int color) { ColorDrawable drawable = new ColorDrawable(color); drawable.setBounds(key.x, key.y, key.x + key.width, key.y + key.height); drawable.draw(canvas); } // 绘制删除按键 private void drawDeleteButton(Keyboard.Key key, Canvas canvas) { if (mDeleteDrawable == null) return; // 计算删除图标绘制的坐标 if (mDeleteDrawRect == null || mDeleteDrawRect.isEmpty()) { int intrinsicWidth = mDeleteDrawable.getIntrinsicWidth(); int intrinsicHeight = mDeleteDrawable.getIntrinsicHeight(); int drawWidth = intrinsicWidth; int drawHeight = intrinsicHeight; // 限制图标的大小，防止图标超出按键 if (drawWidth > key.width) { drawWidth = key.width; drawHeight = drawWidth * intrinsicHeight / intrinsicWidth; } if (drawHeight > key.height) { drawHeight = key.height; drawWidth = drawHeight * intrinsicWidth / intrinsicHeight; } // 获取删除图标绘制的坐标 int left = key.x + (key.width - drawWidth) / 2; int top = key.y + (key.height - drawHeight) / 2; mDeleteDrawRect = new Rect(left, top, left + drawWidth, top + drawHeight); } // 绘制删除的图标 if (mDeleteDrawRect != null && !mDeleteDrawRect.isEmpty()) { mDeleteDrawable.setBounds(mDeleteDrawRect.left, mDeleteDrawRect.top, mDeleteDrawRect.right, mDeleteDrawRect.bottom); mDeleteDrawable.draw(canvas); } } @Override public void onKey(int primaryCode, int[] keyCodes) { // 处理按键的点击事件 // 点击删除按键 if (primaryCode == Keyboard.KEYCODE_DELETE) { if (mOnKeyboardListener != null) { mOnKeyboardListener.onDeleteKeyEvent(); } } // 点击了非左下角按键的其他按键 else if (primaryCode != KEYCODE_EMPTY) { if (mOnKeyboardListener != null) { mOnKeyboardListener.onInsertKeyEvent( Character.toString((char) primaryCode)); } } } @Override public void onPress(int primaryCode) { } @Override public void onRelease(int primaryCode) { } @Override public void onText(CharSequence text) { } @Override public void swipeLeft() { } @Override public void swipeRight() { } @Override public void swipeDown() { } @Override public void swipeUp() { } /** * 设置键盘的监听事件。 * * @param listener * 监听事件 */ public void setIOnKeyboardListener(IOnKeyboardListener listener) { this.mOnKeyboardListener = listener; } public interface IOnKeyboardListener { void onInsertKeyEvent(String text); void onDeleteKeyEvent(); }}2. 自定义属性：
values/attrs.xml
<declare-styleable name="PasswordKeyboardView"> <attr name="pkvDeleteDrawable" format="reference"/> <attr name="pkvDeleteBackgroundColor" format="color|reference"/></declare-styleable>
3. 软键盘按键的布局文件 res/xml/keyboard_number_password：
说明：
<?xml version="1.0" encoding="utf-8"?><Keyboard xmlns:android="http://schemas.android.com/apk/res/android" android:keyWidth="33.33333%p" android:keyHeight="8%p" android:horizontalGap="1dp" android:verticalGap="1dp"> <Row> <Key android:codes="49" android:keyLabel="1"/> <Key android:codes="50" android:keyLabel="2"/> <Key android:codes="51" android:keyLabel="3"/> </Row> <Row> <Key android:codes="52" android:keyLabel="4"/> <Key android:codes="53" android:keyLabel="5"/> <Key android:codes="54" android:keyLabel="6"/> </Row> <Row> <Key android:codes="55" android:keyLabel="7"/> <Key android:codes="56" android:keyLabel="8"/> <Key android:codes="57" android:keyLabel="9"/> </Row> <Row> <Key android:codes="-10" android:keyLabel=""/> <Key android:codes="48" android:keyLabel="0"/> <Key android:codes="-5" android:keyIcon="@mipmap/keyboard_backspace"/> </Row></Keyboard>
3. 在布局中引用软键盘控件：
<[包名].PasswordKeyboardView android:layout_width="match_parent" android:layout_height="wrap_content" android:background="#b0b0b0" android:focusable="true" android:focusableInTouchMode="true" android:keyBackground="#ffffff" android:keyTextColor="#000000" android:shadowColor="#00000000" android:shadowRadius="0" app:pkvDeleteBackgroundColor="#d2d2d2" app:pkvDeleteDrawable="@drawable/keyboard_backspace" />
随机数字键盘的实现
目前能想到的有两种实现方式：
1. 在 onDraw 方法里重新绘制键盘上的文字，覆盖掉原来的键盘，这种实现方式相对比较麻烦。
2. 调用 KeyboardView.setKeyboard() 方法重新设置键盘，实现的代码如下：
// 0-9 的数字private final List<Character> keyCodes = Arrays.asList( '0', '1', '2', '3', '4', '5', '6', '7', '8', '9');/** * 随机打乱数字键盘上显示的数字顺序。 */public void shuffleKeyboard() { Keyboard keyboard = getKeyboard(); if (keyboard != null && keyboard.getKeys() != null && keyboard.getKeys().size() > 0) { // 随机排序数字 Collections.shuffle(keyCodes); // 遍历所有的按键 List<Keyboard.Key> keys = getKeyboard().getKeys(); int index = 0; for (Keyboard.Key key : keys) { // 如果按键是数字 if (key.codes[0] != KEYCODE_EMPTY && key.codes[0] != Keyboard.KEYCODE_DELETE) { char code = keyCodes.get(index++); key.codes[0] = code; key.label = Character.toString(code); } } // 更新键盘 setKeyboard(keyboard); }}调用 shuffleKeyboard 即可生成随机的键盘。
最终实现的效果如下：
随机键盘
踩坑
1. 点击按键的放大镜效果提示
软键盘默认点击按键时会显示放大镜效果的提示，如果不需要可以使用 setPreviewEnabled(false) 设置不显示提示。
可以在布局中使用 android:keyPreviewLayout 指定提示文字的布局。
2. 按键文字不清晰
软键盘按键默认带有阴影效果，会导致文字不清楚，可以使用下面方式去掉阴影：
<[包名].PasswordKeyboardView android:shadowColor="@color/transparent" android:shadowRadius="0" ... />
感谢阅读，希望能帮助到大家，谢谢大家对本站的支持！
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