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());

        }
    });
}

1 -创建一个选择器文件"show_password_selector.xml"

<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:drawable="@drawable/pwd_hide"
          android:state_selected="true"/>
    <item android:drawable="@drawable/pwd_show"
          android:state_selected="false" />
 </selector>

2 -将“show_password_selector”文件放入imageview。

<ImageView
    android:id="@+id/iv_pwd"
    android:layout_width="@dimen/_35sdp"
    android:layout_height="@dimen/_25sdp"
    android:layout_alignParentRight="true"
    android:layout_centerVertical="true"
    android:layout_marginRight="@dimen/_15sdp"
    android:src="@drawable/show_password_selector" />

3 -把下面的代码在java文件。

iv_new_pwd.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        if (iv_new_pwd.isSelected()) {
            iv_new_pwd.setSelected(false);
            Log.d("mytag", "in case 1");
            edt_new_pwd.setInputType(InputType.TYPE_CLASS_TEXT);
        } else {
            Log.d("mytag", "in case 1");
            iv_new_pwd.setSelected(true);
            edt_new_pwd.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);
        }
    }
});

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)
    }

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());

        }
    });
}

用复选框显示和隐藏密码Edit_Text

XML

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent"
    android:layout_height="match_parent">

    <EditText
        android:inputType="textPassword"
        android:id="@+id/edtPass"
        android:textSize="20dp"
        android:hint="password"
        android:padding="20dp"
        android:background="#efeaea"
        android:layout_width="match_parent"
        android:layout_margin="20dp"
        android:layout_height="wrap_content" />

    <CheckBox
        android:background="#ff4"
        android:layout_centerInParent="true"
        android:textSize="25dp"
        android:text="show password"
        android:layout_below="@id/edtPass"
        android:id="@+id/showPassword"
        android:layout_marginTop="20dp"
        android:layout_width="wrap_content"
        android:gravity="top|right"
        android:layout_height="wrap_content" />

</RelativeLayout>

java代码

package com.example.root.sql2;

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.AppCompatCheckBox;
import android.support.v7.widget.Toolbar;
import android.text.method.HideReturnsTransformationMethod;
import android.text.method.PasswordTransformationMethod;
import android.view.View;
import android.widget.CheckBox;
import android.widget.CompoundButton;
import android.widget.EditText;

public class password extends AppCompatActivity {


    EditText password;
    CheckBox show_hide_password;

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



    }//end onCreate



    public void show_hide_pass(){
        show_hide_password.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {
            @Override
            public void onCheckedChanged(CompoundButton compoundButton, boolean b) {
                if (!b){
                    // hide password
                    password.setTransformationMethod(PasswordTransformationMethod.getInstance());

                }else{
                    // show password
                    password.setTransformationMethod(HideReturnsTransformationMethod.getInstance());
                }
            }
        });
    } // end show_hide_pass




    public void findViewById(){ //  find ids ui and
        password = (EditText) findViewById(R.id.edtPass);
        show_hide_password = (CheckBox) findViewById(R.id.showPassword);
    }//end findViewById



}// end class

一个很好的解决方案。设置一个按钮，然后使用下面的代码:

public void showPassword(View v)
{

    TextView showHideBtnText = (TextView) findViewById(R.id.textView1);

    if(showHideBtnText.getText().toString().equals("Show Password")){
        password.setTransformationMethod(null);
        showHideBtnText.setText("Hide");
    } else{
        password.setTransformationMethod(new PasswordTransformationMethod());
        showHideBtnText.setText("Show Password");
    }


}