Question

我有一个程序，我有一个editText。我想实现TextWatcher以反映总edittext中的更改。我想在editbox达到最大字符限制10时显示警告对话框。当我实现文本观察器时，它可以工作，但是当它达到10个字符时它会显示两个警告框。这是我的代码

private TextWatcher mTextEditorWatcher = new TextWatcher() {
    public void beforeTextChanged(CharSequence s, int start, int count,
            int after) {
    }

    public void onTextChanged(CharSequence s, int start, int before,
            int count) {
        // This sets a textview to the current length
        // mTextView.setText(String.valueOf(s.length()));

    }

    public void afterTextChanged(Editable s) {
        if (s.length() == 10) {
            messageBody.setImeOptions(EditorInfo.IME_ACTION_DONE);
            AlertDialog.Builder alert = new AlertDialog.Builder(
                    SendSms.this);

            alert.setMessage("You Cross the limit of 10 Words !");
            alert.setPositiveButton("OK",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog,
                                int whichButton) {

                        }
                    });

            alert.show();

        }

    }
};

Answer 1

 AlertDialog.Builder alertDialogBuilder = new AlertDialog.Builder(
             SendSms.this);
     AlertDialog alertDialog ;

 private TextWatcher mTextEditorWatcher = new TextWatcher() {
        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {
        }

        public void onTextChanged(CharSequence s, int start, int before,
                int count) {
            // This sets a textview to the current length
            // mTextView.setText(String.valueOf(s.length()));

      if (s.length() >= 10) {
                messageBody.setImeOptions(EditorInfo.IME_ACTION_DONE);
                        alertDialogBuilder.setMessage("You Cross the limit of 10 Words !");
         alertDialogBuilder.setPositiveButton("OK",
                 new DialogInterface.OnClickListener() {
                     public void onClick(DialogInterface dialog,
                             int whichButton) {

                     }
                 });

         alertDialog = alertDialogBuilder.create();
         if(alertDialog != null  && !alertDialog.isShowing()){
             alertDialog.show();
         }



            }
    else
    {
       mTextView.setText(String.valueOf(s.length()));
    }



        }

        public void afterTextChanged(Editable s) {


        }
    };

我编写了代码。全局声明警报对话框并检查是否已显示alertDialog，然后显示警报

Answer 2

这是此方法的常见行为。你需要处理使用旗帜。

使用此代码

   private TextWatcher mTextEditorWatcher = new TextWatcher() {
        boolean flag = false; 

    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count,
            int after) {
    }

    @Override
    public void afterTextChanged(Editable s) {
        if (s.length() == 10) {
            if (!flag) {
                messageBody.setImeOptions(EditorInfo.IME_ACTION_DONE);
                AlertDialog.Builder alert = new AlertDialog.Builder(
                        SendSms.this);

                alert.setMessage("You Cross the limit of 10 Words !");
                alert.setPositiveButton("OK",
                        new DialogInterface.OnClickListener() {
                            public void onClick(DialogInterface dialog,
                                    int whichButton) {

                            }
                        });

                alert.show();
            }
            flag = true; 
        } else {
            flag = false; 
        }

    }
});

其他参考资料

TextWatcher events are being fired multiple times

Events of TextWatcher are being called twice

最好是使用setError。阅读how to use it.

Answer 3

试试这个..

你试过onTextChanged

吗？

private TextWatcher mTextEditorWatcher = new TextWatcher() {
    public void beforeTextChanged(CharSequence s, int start, int count,
            int after) {
    }

    public void onTextChanged(CharSequence s, int start, int before,
            int count) {
        // This sets a textview to the current length
        // mTextView.setText(String.valueOf(s.length()));


        if (s.length() == 10) {
            messageBody.setImeOptions(EditorInfo.IME_ACTION_DONE);
            AlertDialog.Builder alert = new AlertDialog.Builder(
                    SendSms.this);

            alert.setMessage("You Cross the limit of 10 Words !");
            alert.setPositiveButton("OK",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog,
                                int whichButton) {

                        }
                    });

            alert.show();

        }

    }

    public void afterTextChanged(Editable s) {

    }
};

Answer 4

只需将警报实例设为全局，即可正常使用。

    private AlertDialog.Builder alert ;

你的onCreate

中的

    alert = new AlertDialog.Builder(
                 RegisterActivity.this);

你的afterTextChanged

中的

    public void afterTextChanged(Editable s) {
        if (s.length() == 10) {
            //messageBody.setImeOptions(EditorInfo.IME_ACTION_DONE);
            alert.setMessage("You Cross the limit of 10 Words !");
            alert.setPositiveButton("OK",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog,
                                int whichButton) {

                        }
                    });

            alert.show();

        }

    }

Answer 5

您好我为电话号码做了这样的工作，当它达到5位数时，它会自动放置空间。你可以利用我的代码。请查看以下代码。

public void onTextChanged(CharSequence s, int start, int before,
                int count) {
            if (s.length() == 5 && start == 4) {
                txtNumber.removeTextChangedListener(this);
                txtNumber.append(" ");
                txtNumber.addTextChangedListener(this);
            }
            if (s.length() == 6 && start == 5) {
                txtNumber.removeTextChangedListener(this);
                String newtext = s.toString().substring(0, s.length() - 1)
                        + " " + s.charAt(s.length() - 1);
                txtNumber.setText("");
                txtNumber.append(newtext);
                txtNumber.addTextChangedListener(this);
            }
        }

如果您需要更多帮助，请告诉我

Answer 6

尝试以下代码：

全球实例：

private AlertDialog.Builder alert;

TextWatcher：

private TextWatcher mTextEditorWatcher = new TextWatcher() {

    public void beforeTextChanged(CharSequence s, int start, int count, int after) {
    }

    public void onTextChanged(CharSequence s, int start, int before, int count) {
        if (s.length() >= 10) {
            messageBody.setImeOptions(EditorInfo.IME_ACTION_DONE);
            // alert = new AlertDialog.Builder(MainActivity.this);
            // alert.setMessage("You Cross the limit of 10 Words !");
            // alert.setPositiveButton("OK", new DialogInterface.OnClickListener() {
            // public void onClick(DialogInterface dialog, int whichButton) {
            // }
            // });
            // alert.show();

            // Else you should use the following one to show error message
            messageBody.setError("You Cross the limit of 10 Words !");

        } else {
            messageBody.setError(null);
        }

    }

    public void afterTextChanged(Editable s) {
    }
};

Android中的文本观察者

6 个答案: