Android仿微信实现安全数字键盘功能-技术圈

背景

大部分的金融App会对默认的数字键盘进行处理，以实现自定义的数字安全键盘。基于此，本文对对微信数字键盘样式进行了仿写，实现了一套自定义的数字安全键盘（支持随机数字分布）。

一、图示效果

二、需要考虑的问题

布局的实现方式；
demo中使用了popupwindow，通过xml文件进行Tablayout布局。
禁掉EditText默认软键盘的弹出，替换为自定义的数字键盘及与其它EditText切换焦点时的弹出效果；
删除和增加字符时需要同步更新光标的位置；
随机数字分布的实现；

三、实现代码

1.MainActivity调用处代码：

public class MainActivity extends AppCompatActivity {    private static final String TAG = "MainActivity";    private EditText numberEt;    private KeyboardPopupWindow keyboardPopupWindow;    private boolean isUiCreated = false;
    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        initView();    }
    private void initView() {        numberEt = findViewById(R.id.numberEt);        keyboardPopupWindow = new KeyboardPopupWindow(MainActivity.this, getWindow().getDecorView(), numberEt,true);//        numberEt.setInputType(InputType.TYPE_NULL);//该设置会导致光标不可见        numberEt.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                if (keyboardPopupWindow != null) {                    keyboardPopupWindow.show();                }            }        });        numberEt.setOnFocusChangeListener(new View.OnFocusChangeListener() {            @Override            public void onFocusChange(View v, boolean hasFocus) {                if (keyboardPopupWindow != null && isUiCreated) {//isUiCreated 很重要，Unable to add window -- token null is not valid; is your activity running?                    keyboardPopupWindow.refreshKeyboardOutSideTouchable(!hasFocus);// 需要等待页面创建完成后焦点变化才去显示自定义键盘                }
                if (hasFocus) {//隐藏系统软键盘                    InputMethodManager imm = (InputMethodManager) getSystemService(Context.INPUT_METHOD_SERVICE);                    imm.hideSoftInputFromWindow(numberEt.getWindowToken(), 0);                }
            }        });    }
    @Override    public void onWindowFocusChanged(boolean hasFocus) {        super.onWindowFocusChanged(hasFocus);        isUiCreated = true;    }

    @Override    protected void onDestroy() {        if (keyboardPopupWindow != null) {            keyboardPopupWindow.releaseResources();        }        super.onDestroy();    }}

可以看到，这块的代码实现很简单，主要是通过KeyboardPopupWindow 这个自定义的View来实现键盘弹出及按键点击效果。需要注意的是isUiCreated 这个标志位，需要通过onWindowFocusChanged等方法来确定当前页面加载完毕后去刷新自定义键盘的状态，否则会报错。

2.自定义数字键盘的代码：

public class KeyboardPopupWindow extends PopupWindow {    private static final String TAG = "KeyboardPopupWindow";    private Context context;    private View anchorView;    private View parentView;    private EditText editText;    private boolean isRandomSort = false;//数字是否随机排序    private List<Integer> list = new ArrayList<>();    private int[] commonButtonIds = new int[]{R.id.button00, R.id.button01, R.id.button02, R.id.button03,            R.id.button04, R.id.button05, R.id.button06, R.id.button07, R.id.button08, R.id.button09};
    /**     * @param context     * @param anchorView     * @param editText     * @param isRandomSort 数字是否随机排序     */    public KeyboardPopupWindow(Context context, View anchorView, EditText editText, boolean isRandomSort) {        this.context = context;        this.anchorView = anchorView;        this.editText = editText;        this.isRandomSort = isRandomSort;        if (context == null || anchorView == null) {            return;        }        initConfig();        initView();    }

    private void initConfig() {        setOutsideTouchable(false);        setFocusable(false);        setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));        forbidDefaultSoftKeyboard();    }
    /**     * 禁止系统默认的软键盘弹出     */    private void forbidDefaultSoftKeyboard() {        if (editText == null) {            return;        }        if (android.os.Build.VERSION.SDK_INT > 10) {//4.0以上，使用反射的方式禁止系统自带的软键盘弹出            try {                Class<EditText> cls = EditText.class;                Method setShowSoftInputOnFocus;                setShowSoftInputOnFocus = cls.getMethod("setShowSoftInputOnFocus", boolean.class);                setShowSoftInputOnFocus.setAccessible(true);                setShowSoftInputOnFocus.invoke(editText, false);            } catch (Exception e) {                e.printStackTrace();            }        }    }
    /**     * 刷新自定义的popupwindow是否outside可触摸反应：如果是不可触摸的，则显示该软键盘view     *     * @param isTouchable     */    public void refreshKeyboardOutSideTouchable(boolean isTouchable) {        setOutsideTouchable(isTouchable);        if (!isTouchable) {            show();        } else {            dismiss();        }    }
    private void initView() {        parentView = LayoutInflater.from(context).inflate(R.layout.keyboadview, null);        initKeyboardView(parentView);        setWidth(ViewGroup.LayoutParams.MATCH_PARENT);        setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);        setContentView(parentView);    }
    private void initKeyboardView(View view) {        LinearLayout dropdownLl = view.findViewById(R.id.dropdownLl);        dropdownLl.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                dismiss();            }        });
        //①给数字键设置点击监听        for (int i = 0; i < commonButtonIds.length; i++) {            final Button button = view.findViewById(commonButtonIds[i]);            button.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View v) {                    int curSelection = editText.getSelectionStart();                    int length = editText.getText().toString().length();                    if (curSelection < length) {                        String content = editText.getText().toString();                        editText.setText(content.substring(0, curSelection) + button.getText() + content.subSequence(curSelection, length));                        editText.setSelection(curSelection + 1);                    } else {                        editText.setText(editText.getText().toString() + button.getText());                        editText.setSelection(editText.getText().toString().length());                    }                }            });        }
        //②给小数点按键设置点击监听        view.findViewById(R.id.buttonDot).setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                int curSelection = editText.getSelectionStart();                int length = editText.getText().toString().length();                if (curSelection < length) {                    String content = editText.getText().toString();                    editText.setText(content.substring(0, curSelection) + "." + content.subSequence(curSelection, length));                    editText.setSelection(curSelection + 1);                } else {                    editText.setText(editText.getText().toString() + ".");                    editText.setSelection(editText.getText().toString().length());                }            }        });
        //③给叉按键设置点击监听        view.findViewById(R.id.buttonCross).setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                int length = editText.getText().toString().length();                int curSelection = editText.getSelectionStart();                if (length > 0 && curSelection > 0 && curSelection <= length) {                    String content = editText.getText().toString();                    editText.setText(content.substring(0, curSelection - 1) + content.subSequence(curSelection, length));                    editText.setSelection(curSelection - 1);                }            }        });    }

    public void show() {        if (!isShowing() && anchorView != null) {            doRandomSortOp();            this.showAtLocation(anchorView, Gravity.BOTTOM, 0, 0);        }    }
    /**     * 随机分布数字     */    private void doRandomSortOp() {        if (parentView == null) {            return;        }        if (!isRandomSort) {            for (int i = 0; i < commonButtonIds.length; i++) {                final Button button = parentView.findViewById(commonButtonIds[i]);                button.setText("" + i);            }        } else {            list.clear();            Random ran = new Random();            while (list.size() < commonButtonIds.length) {                int n = ran.nextInt(commonButtonIds.length);                if (!list.contains(n))                    list.add(n);            }            for (int i = 0; i < commonButtonIds.length; i++) {                final Button button = parentView.findViewById(commonButtonIds[i]);                button.setText("" + list.get(i));            }        }    }
    public void releaseResources() {        this.dismiss();        context = null;        anchorView = null;        if (list != null) {            list.clear();            list = null;        }    }  }

代码实现的逻辑相对简单：

通过给popupwindow设置contentView、弹出位置、边界外触摸参数等数值，实现大体样式上的效果；
给contentView中的每个button设置点击事件，并处理传递的EditText数值及焦点变化情况；
设置随机标志位，进行数值键盘数值随机的分布；
forbidDefaultSoftKeyboard中处理：禁止EditText默认的软键盘弹出。因为要实现EditText焦点仍旧可见的效果，目前试过的其它集中方式仍有较大的缺陷，所以是通过反射的方法来达到目的。

四.小结

当然，除了以上方式，还可以使用系统的KeyboardView和Keyboard来实现相应的效果。

在仿写的过程中会发现，实现这一效果会涉及到一些体验性的细节点，而微信正是做到了这一点，所以在使用层面上会很方便。有些细节点会可能会比实现整个大致效果更为麻烦，但有时候恰巧这些很容易被忽视的小九九是与众不同的地方。

源码地址：

https://github.com/ganshenml/KeyboardPopupWindow

到这里就结束啦。