在Android中,如何让登录按钮相对于EditText上禁用?(In Android, how t

2019-07-20 07:53发布

如果EditText为空,则登录Button已被禁用。 如果EditText有一些文本,然后登录Button已被启用。 那么你可以看到Instagram的登录此方法。

这两个字段为空,登录Button被禁用。

这里密码字段为空,所以还是请登录Button被禁用。

这里既有用户名和密码字段不为空,所以登录Button被启用。

如何实现这些步骤? 这里是我的代码,它不工作..

EditText et1,et2;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_login_check);
    et1 = (EditText) findViewById(R.id.editText1);
    et2 = (EditText) findViewById(R.id.editText2);
    Button b = (Button) findViewById(R.id.button1);

    String s1 = et1.getText().toString();
    String s2 = et2.getText().toString();

    if(s1.equals("")|| s2.equals("")){
        b.setEnabled(false);
    } else {
        b.setEnabled(true);
    }
}

Answer 1:

继承人你在找什么:

private EditText et1,et2;
//  create a textWatcher member
private TextWatcher mTextWatcher = new TextWatcher() {
    @Override
    public void beforeTextChanged(CharSequence charSequence, int i, int i2, int i3) {
    }

    @Override
    public void onTextChanged(CharSequence charSequence, int i, int i2, int i3) {
    }

    @Override
    public void afterTextChanged(Editable editable) {
        // check Fields For Empty Values
        checkFieldsForEmptyValues();
    }
};

void checkFieldsForEmptyValues(){
    Button b = (Button) findViewById(R.id.button1);

    String s1 = et1.getText().toString();
    String s2 = et2.getText().toString();

    if(s1.equals("")|| s2.equals("")){
        b.setEnabled(false);
    } else {
        b.setEnabled(true);
    }
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_login_check);
    et1 = (EditText) findViewById(R.id.editText1);
    et2 = (EditText) findViewById(R.id.editText2);


    // set listeners
    et1.addTextChangedListener(mTextWatcher);
    et2.addTextChangedListener(mTextWatcher);

    // run once to disable if empty
    checkFieldsForEmptyValues(); 
}


Answer 2:

您需要实现TextWatcherEditText达到的效果。

EditText et1, et2;
Button b;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    et1 = (EditText) findViewById(R.id.editText1);
    et2 = (EditText) findViewById(R.id.editText2);
    b = (Button) findViewById(R.id.button1);

    checkValidation();

    et1.addTextChangedListener(mWatcher);
    et2.addTextChangedListener(mWatcher);
}

private void checkValidation() {
    // TODO Auto-generated method stub

    if ((TextUtils.isEmpty(et1.getText()))
            || (TextUtils.isEmpty(et2.getText())))
        b.setEnabled(false);
    else
        b.setEnabled(true);

}

TextWatcher mWatcher = new TextWatcher() {

    @Override
    public void onTextChanged(CharSequence s, int start, int before,
            int count) {
        // TODO Auto-generated method stub
        checkValidation();
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count,
            int after) {
        // TODO Auto-generated method stub

    }

    @Override
    public void afterTextChanged(Editable s) {
        // TODO Auto-generated method stub

    }
};


Answer 3:

你需要跟踪用户的行为里面EditText使用TextWatcher对象:

myEditText.addTextChangedListener(new TextWatcher()
        {

            @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() > 1)
                {
                    //enable button
                } else
                    //disable
            }
        });


Answer 4:

试试这个:

EditText et1,et2;
Button b;

@Override
protected void onCreate(Bundle savedInstanceState) {

  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_login_check);
  et1 = (EditText) findViewById(R.id.editText1);
  et2 = (EditText) findViewById(R.id.editText2);
  b = (Button) findViewById(R.id.button1);


  et1.addTextChangedListener(new TextWatcher() {

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

                            String s1 = et1.getText().toString();
                            String s2 = et2.getText().toString();

                             if(s1.equals("") && s2.equals("")){
                                   b.setEnabled(false);
                            } 
                            else if(!s1.equals("")&&s2.equals("")){
                                   b.setEnabled(false);
                            }
                            else if(!s2.equals("")&&s1.equals(""){
                                   b.setEnabled(false);
                            }
                            else {
                            b.setEnabled(true);
                          }

        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {
            // TODO Auto-generated method stub

        }

        @Override
        public void afterTextChanged(Editable s) {
            // TODO Auto-generated method stub

        }
    });
  et2.addTextChangedListener(new TextWatcher() {

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

                            String s1 = et1.getText().toString();
                            String s2 = et2.getText().toString();

                            if(s1.equals("") && s2.equals("")){
                                   b.setEnabled(false);
                            } 
                            else if(!s1.equals("")&&s2.equals("")){
                                   b.setEnabled(false);
                            }
                            else if(!s2.equals("")&&s1.equals(""){
                                   b.setEnabled(false);
                            }
                            else {
                            b.setEnabled(true);
                          }

        }

        @Override
        public void beforeTextChanged(CharSequence s, int start, int count,
                int after) {
            // TODO Auto-generated method stub

        }

        @Override
        public void afterTextChanged(Editable s) {
            // TODO Auto-generated method stub

        }
    });

}


Answer 5:

您需要附上每当在EditText上的一个字段的文本更改被称为TextWatcher。

private EditText mName;
private EditText mPassword;
private Button mButton;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_login_check);
    mName = (EditText) findViewById(R.id.editText1);
    mPassword = (EditText) findViewById(R.id.editText2);
    mButton = (Button) findViewById(R.id.button1);

    mName.addTextChangedListener(mWatcher);
    mPassword.addTextChangedListener(mWatcher);
}

private TextWatcher mWatcher = new TextWatcher() {
    @Override
    public void afterTextChanged(Editable s) {
        boolean nameNotEmpty = mName.getText().length()>0;
        boolean pwNotEmpty = mPassword.getText().length()>0;
        mButton.setEnabled(nameNotEmpty && pwNotEmpty);
    }
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {}
    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {}
};


Answer 6:

private TextWatcher mPhoneNumberEtWatcher = new TextWatcher() {
    @Override
    public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {}

    @Override
    public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {
        if (charSequence.length() >= 10) {
            mPhoneImg.setImageDrawable(getResources().getDrawable(R.drawable.phone_activate));

            if (mPasswordEt.getText().toString().length() >= 5) {
                mLoginBtn.setEnabled(true);
            }

        } else {
            mPhoneImg.setImageDrawable(getResources().getDrawable(R.drawable.phone));
            mLoginBtn.setEnabled(false);
        }
    }

    @Override
    public void afterTextChanged(Editable editable) {
    }
};

mPhoneNumberEt.addTextChangedListener(mPhoneNumberEtWatcher);

您应该使用TextWatcher。 这将用户输入后调用方法。 你可以检查长度和财产以后否则你编辑的文本。



Answer 7:

试试这个

  if(s1.equals("") && s2.equals(""))
    {
        b.setEnabled(true);
        // to change color of the button you need to apply style to the button[here refer custom bg][1]
    }
    else
    {
        b.setEnabled(false);
       //do nothing or display toast msg
    }


Answer 8:

我只想补充一点,如果该检查将不起作用 InputType的的EditText是一个密码(或类似)和机能的研究,以证明文本的长度(见其他答案)是由被称为

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

因此,它调用从检查是非常重要的

@Override 
public void afterTextChanged(Editable s) {...}


Answer 9:

哎,如果想使用代码切断按钮需要改变颜色,如果editText1_id和editText1_passcode是在4位

checkValidation();

    editText1_id.addTextChangedListener(mWatcher);
    editText1_passcode.addTextChangedListener(mWatcher);
}

private void checkValidation() {
    // TODO Auto-generated method stub

    if ((TextUtils.isEmpty(editText1_id.getText()))
            || (TextUtils.isEmpty(editText1_passcode.getText())))
        loginbtn.setEnabled(false);
    else
        loginbtn.setEnabled(true);

}


TextWatcher mWatcher = new TextWatcher() {

    @Override
    public void onTextChanged(CharSequence s, int start, int before,
                              int count) {
        // TODO Auto-generated method stub
        checkValidation();
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count,
                                  int after) {
        // TODO Auto-generated method stub

    }

    @Override
    public void afterTextChanged(Editable s) {
        // TODO Auto-generated method stub

    }
};

}


Answer 10:

1号线的解决方案?

设置按钮依赖的EditText是超级简单 的数据绑定 。 您可以通过只XML管理。

android:enabled="@{etName.text.length() > 5 && etPassword.text.length() > 5}"
  • 这里& 是HTML实体 ,该名称表示& 。 有可以像与任何运营商。

  • etNameetPassword是EditTexts IDS。

完整的XML -

<LinearLayout
    >

    <EditText
        android:id="@+id/etName"
        />

    <EditText
        android:id="@+id/etPassword"
        />

    <Button
        android:enabled="@{etName.text.length() > 5 &amp;&amp; etPassword.text.length() > 5}"
        />

</LinearLayout>



文章来源: In Android, how to make Login button disable with respect to EditText?