<?xml version="1.0" encoding="utf-8"?><LinearLayout  xmlns:android="http://schemas.android.com/apk/res/android"  android:layout_width="match_parent"  android:layout_height="match_parent"  android:orientation="vertical"  >  <EditText    android:id="@+id/et"    android:layout_width="match_parent"    android:layout_height="50dp"    android:layout_marginTop="25dp"    android:hint="請輸入數據"    />  <LinearLayout    android:layout_width="match_parent"    android:layout_height="50dp"    android:orientation="horizontal">    <Button      android:id="@+id/password"      android:layout_width="0dp"      android:layout_height="match_parent"      android:layout_weight="1"      android:text="密文"/>    <Button      android:id="@+id/show_text"      android:layout_width="0dp"      android:layout_height="match_parent"      android:layout_marginLeft="20dp"      android:layout_weight="1"      android:text="明文"/>  </LinearLayout>  <Button    android:id="@+id/clean"    android:layout_width="match_parent"    android:layout_height="50dp"    android:text="清除"/></LinearLayout>

package com.chen;import android.app.Activity;import android.os.Bundle;import android.text.method.HideReturnsTransformationMethod;import android.text.method.PasswordTransformationMethod;import android.view.View;import android.widget.Button;import android.widget.EditText;public class MainActivity extends Activity {  Button psd;  Button show_text;  EditText et;  Button clean;  @Override  protected void onCreate(Bundle savedInstanceState) {    super.onCreate(savedInstanceState);    setContentView(R.layout.activity_main);    //將輸入框中的內容變為密碼格式    psd = (Button) findViewById(R.id.password);    //將密碼變為明文    show_text = (Button) findViewById(R.id.show_text);    //清空輸入框    clean = (Button) findViewById(R.id.clean);    et = (EditText) findViewById(R.id.et);    show_text.setOnClickListener(new View.OnClickListener() {      @Override      public void onClick(View v) {        //獲取編輯框中的數據內容        String context = et.getText().toString();        //將密碼變為明文，這里不用setInputType        et.setTransformationMethod(HideReturnsTransformationMethod.getInstance());        //設置光標位置在數據最后        et.setSelection(context.length());      }    });    psd.setOnClickListener(new View.OnClickListener() {      @Override      public void onClick(View v) {        //獲取編輯框中的數據內容        String context = et.getText().toString();        //將數據變為指定樣式的密碼        et.setTransformationMethod(new AsteriskPasswordTransformationMethod());        //設置光標位置在數據最后        et.setSelection(context.length());      }    });    clean.setOnClickListener(new View.OnClickListener() {      @Override      public void onClick(View v) {        et.setText("");      }    });  }  private class AsteriskPasswordTransformationMethod extends PasswordTransformationMethod {    @Override    public CharSequence getTransformation(CharSequence source, View view) {      return new PasswordCharSequence(source);    }    private class PasswordCharSequence implements CharSequence {      private CharSequence mSource;      public PasswordCharSequence(CharSequence source) {        mSource = source; // Store char sequence      }      public char charAt(int index) {        /*        當在編輯框中輸入1的時候，會連續打印0...        當在編輯框中繼續輸入2的時候，會連續01...        不影響功能使用，但是出現原因不知，待解決         */        System.out.println("-----" + index + "-----");        //這里返回的char，就是密碼的樣式，注意，是char類型的        return '$'; // This is the important part      }      public int length() {        return mSource.length(); // Return default      }      public CharSequence subSequence(int start, int end) {        return mSource.subSequence(start, end); // Return default      }    }  }}