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)
    }

使用复选框并相应地更改输入类型。

public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
    int start,end;
    Log.i("inside checkbox chnge",""+isChecked);
    if(!isChecked){
        start=passWordEditText.getSelectionStart();
        end=passWordEditText.getSelectionEnd();
        passWordEditText.setTransformationMethod(new PasswordTransformationMethod());;
        passWordEditText.setSelection(start,end);
    }else{
        start=passWordEditText.getSelectionStart();
        end=passWordEditText.getSelectionEnd();
        passWordEditText.setTransformationMethod(null);
        passWordEditText.setSelection(start,end);
    }
}

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());
                }
            }

        });

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());

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)
    }

你可以使用下面的代码显示/隐藏密码:

XML代码:

<EditText
        android:id="@+id/etPassword"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginLeft="21dp"
        android:layout_marginTop="14dp"
        android:ems="10"
        android:inputType="textPassword" >
        <requestFocus />
    </EditText>
    <CheckBox
        android:id="@+id/cbShowPwd"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignLeft="@+id/etPassword"
        android:layout_below="@+id/etPassword"
        android:text="@string/show_pwd" />

JAVA代码:

EditText mEtPwd;
CheckBox mCbShowPwd;


mEtPwd = (EditText) findViewById(R.id.etPassword);
mCbShowPwd = (CheckBox) findViewById(R.id.cbShowPwd);

mCbShowPwd.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
    @Override
    public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {
        // checkbox status is changed from uncheck to checked.
        if (!isChecked) {
            // show password
            mEtPwd.setTransformationMethod(PasswordTransformationMethod.getInstance());
        } else {
            // hide password
            mEtPwd.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
        }
    }
});