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Android 實現自定義安全數字鍵盤(仿微信)

背景

大部分的金融App會對預設的數字鍵盤進行處理,以實現自定義的數字安全鍵盤。基於此,本文對對微信數字鍵盤樣式進行了仿寫,實現了一套自定義的數字安全鍵盤(支援隨機數字分佈)。

一.圖示效果

在這裡插入圖片描述

二.需要考慮的問題

  1. 佈局的實現方式;
    demo中使用了popupwindow,通過xml檔案進行Tablayout佈局。
  2. 禁掉EditText預設軟鍵盤的彈出,替換為自定義的數字鍵盤及與其它EditText切換焦點時的彈出效果;
  3. 刪除和增加字元時需要同步更新游標的位置;
  4. 隨機數字分佈的實現;

三.實現程式碼

1.MainActivity呼叫處程式碼:

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);//該設定會導致游標不可見
        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);// 需要等待頁面建立完成後焦點變化才去顯示自定義鍵盤
                }

                if (hasFocus) {//隱藏系統軟鍵盤
                    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,這塊的程式碼實現很簡單,主要是通過KeyboardPopupWindow 這個自定義的View來實現鍵盤彈出及按鍵點選效果。需要注意的是isUiCreated 這個標誌位,需要通過onWindowFocusChanged等方法來確定當前頁面載入完畢後去重新整理自定義鍵盤的狀態,否則會報錯。

2.自定義數字鍵盤的程式碼:


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;//數字是否隨機排序
    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 數字是否隨機排序
     */
    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();
    }

    /**
     * 禁止系統預設的軟鍵盤彈出
     */
    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統自帶的軟鍵盤彈出
            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();
            }
        }
    }

    /**
     * 重新整理自定義的popupwindow是否outside可觸控反應:如果是不可觸控的,則顯示該軟鍵盤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給數字鍵設定點選監聽
        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給小數點按鍵設定點選監聽
        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給叉按鍵設定點選監聽
        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);
        }
    }

    /**
     * 隨機分佈數字
     */
    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;
        }
    }
    
}

程式碼實現的邏輯相對簡單:

  1. 通過給popupwindow設定contentView、彈出位置、邊界外觸控引數等數值,實現大體樣式上的效果;
  2. 給contentView中的每個button設定點選事件,並處理傳遞的EditText數值及焦點變化情況;
  3. 設定隨機標誌位,進行數值鍵盤數值隨機的分佈;
  4. forbidDefaultSoftKeyboard中處理:禁止EditText預設的軟鍵盤彈出。因為要實現EditText焦點仍舊可見的效果,目前試過的其它集中方式仍有較大的缺陷,所以是通過反射的方法來達到目的。

四.小結

當然,除了以上方式,還可以使用系統的KeyboardView和Keyboard來實現相應的效果。
在仿寫的過程中會發現,實現這一效果會涉及到一些體驗性的細節點,而微信正是做到了這一點,所以在使用層面上會很方便。有些細節點會可能會比實現整個大致效果更為麻煩,但有時候恰巧這些很容易被忽視的小九九是與眾不同的地方。
最後附上GitHub的原始碼地址:

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