private int passwordNotVisible=1; 
  @Override
  protected void onCreate(Bundle savedInstanceState) {
 showPassword = (ImageView) findViewById(R.id.show_password);
    showPassword.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            EditText paswword = (EditText) findViewById(R.id.Password);
            if (passwordNotVisible == 1) {
                paswword.setInputType(InputType.TYPE_TEXT_VARIATION_VISIBLE_PASSWORD);
                passwordNotVisible = 0;
            } else {

                paswword.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);
                passwordNotVisible = 1;
            }


            paswword.setSelection(paswword.length());

        }
    });
}

您必须询问当前文本是否已经显示了圆点，函数PasswordTransformationMethod.getInstance()允许您这样做。

这是我在kotlin中的函数:

        fun hideAndShowPassword(editText: EditText, indicator: ImageView) {

        if (editText.transformationMethod == PasswordTransformationMethod.getInstance()) {
            editText.transformationMethod = HideReturnsTransformationMethod.getInstance()
            indicator.setImageDrawable(
                ContextCompat.getDrawable(
                    editText.context,
                    R.drawable.eye
                )
            )
            indicator.imageTintList =
                ContextCompat.getColorStateList(editText.context, R.color.colorTintIcons)
        } else {
            editText.transformationMethod = PasswordTransformationMethod.getInstance()
            indicator.setImageDrawable(
                ContextCompat.getDrawable(
                    editText.context,
                    R.drawable.eye_off
                )
            )
            indicator.imageTintList =
                ContextCompat.getColorStateList(editText.context, R.color.colorTintIcons)
        }

        editText.setSelection(editText.text.length)
    }

显示:

editText.setInputType(InputType.TYPE_TEXT_VARIATION_VISIBLE_PASSWORD);

隐藏:

editText.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);

在这些之后，光标被重置，所以:

editText.setSelection(editText.length());

只需在Xml文件中创建一个复选框

然后简单的用Java代码编写这个函数

checkbox = findViewById(R.id.checkbox);
        checkbox.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener(){
            @Override
            public void onCheckedChanged(CompoundButton buttonView, boolean isChecked){

                if (isChecked) {
                    password.setTransformationMethod(null);
                }
                else{
                    password.setTransformationMethod(new PasswordTransformationMethod());
                }
            }

        });

我的Kotlin扩展。编写一次，随处使用

fun EditText.tooglePassWord() {
this.tag = !((this.tag ?: false) as Boolean)
this.inputType = if (this.tag as Boolean)
    InputType.TYPE_TEXT_VARIATION_PASSWORD
else
    (InputType.TYPE_CLASS_TEXT or InputType.TYPE_TEXT_VARIATION_PASSWORD)

this.setSelection(this.length()) }

您可以将此方法保存在任何文件中，并在任何地方使用它 像这样使用它

ivShowPassword.click { etPassword.tooglePassWord() }

其中ivShowPassword是点击imageview(眼睛)和etPassword是编辑

if (inputPassword.getTransformationMethod() == PasswordTransformationMethod.getInstance()) {
 //password is visible
                inputPassword.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
            }
else if(inputPassword.getTransformationMethod() == HideReturnsTransformationMethod.getInstance()) {
 //password is hidden
                inputPassword.setTransformationMethod(PasswordTransformationMethod.getInstance());
            }