1、實現自己的EditText

package com.ming.doustec.clearableedittextdemo;

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.support.v4.content.ContextCompat;
import android.support.v4.graphics.drawable.DrawableCompat;
import android.support.v7.widget.AppCompatEditText;
import android.text.Editable;
import android.text.TextWatcher;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;

/**
 * Created by ds03 on 2015/9/11.
 */
public class ClearableEditText extends AppCompatEditText implements View.OnTouchListener, View.OnFocusChangeListener, TextWatcher {

    private Drawable mClearTextIcon;
    private OnFocusChangeListener mOnFocusChangeListener;
    private OnTouchListener mOnTouchListener;

    public ClearableEditText(Context context) {
        super(context);
        init(context);
    }

    public ClearableEditText(Context context, AttributeSet attrs) {
        super(context, attrs);
        init(context);
    }

    public ClearableEditText(Context context, AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
        init(context);
    }

    private void init(Context context){
        //封裝drawable物件
        Drawable drawable = ContextCompat.getDrawable(context,R.drawable.abc_ic_clear_mtrl_alpha);
        Drawable wrappedDrawable = DrawableCompat.wrap(drawable);
        //簡單著色
        DrawableCompat.setTint(wrappedDrawable, getCurrentHintTextColor());

        mClearTextIcon = wrappedDrawable;
        //設定寬高
        mClearTextIcon.setBounds(0, 0, mClearTextIcon.getIntrinsicHeight(), mClearTextIcon.getIntrinsicWidth());

        setClearIconVisible(false);

        super.setOnTouchListener(this);
        super.setOnFocusChangeListener(this);
        addTextChangedListener(this);
    }

    private void setClearIconVisible(final boolean visible) {
        mClearTextIcon.setVisible(visible, false);
        final Drawable[] compoundDrawables = getCompoundDrawables();
        //在edittext右側設定圖示
        setCompoundDrawables(
                compoundDrawables[0],
                compoundDrawables[1],
                visible ? mClearTextIcon : null,
                compoundDrawables[3]);
    }

    @Override
    public void onFocusChange(View v, boolean hasFocus) {
        if (hasFocus) {
            setClearIconVisible(getText().length() > 0);
        } else {
            setClearIconVisible(false);
        }
        if (mOnFocusChangeListener != null) {
            mOnFocusChangeListener.onFocusChange(v, hasFocus);
        }
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        final int x = (int) event.getX();
        if (mClearTextIcon.isVisible() && x > getWidth() - getPaddingRight() - mClearTextIcon.getIntrinsicWidth()) {
            if (event.getAction() == MotionEvent.ACTION_UP) {
                setError(null);
                setText("");
            }
            return true;
        }
        return mOnTouchListener != null && mOnTouchListener.onTouch(v, event);
    }

    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {

    }

    @Override
    public void afterTextChanged(Editable s) {

    }
    @Override
    public final void onTextChanged(final CharSequence s, final int start, final int before, final int count) {
        if (isFocused()) {
            setClearIconVisible(s.length() > 0);
        }
    }

    @Override
    public void setOnFocusChangeListener(final OnFocusChangeListener onFocusChangeListener) {
        mOnFocusChangeListener = onFocusChangeListener;
    }

    @Override
    public void setOnTouchListener(final OnTouchListener onTouchListener) {
        mOnTouchListener = onTouchListener;
    }
}
                                                                                                                                                                                                                                                                                                                                                                               
 

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:gravity="center_horizontal"
    android:orientation="vertical"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".LoginActivity">

    <!-- Login progress -->
    <ProgressBar
        android:id="@+id/login_progress"
        style="?android:attr/progressBarStyleLarge"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginBottom="8dp"
        android:visibility="gone" />

    <ScrollView
        android:id="@+id/login_form"
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <LinearLayout
            android:id="@+id/email_login_form"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:orientation="vertical">

            <android.support.design.widget.TextInputLayout
                android:id="@+id/email_text_input_layout"
                android:layout_width="match_parent"
                android:layout_height="wrap_content">

                <com.ming.doustec.clearableedittextdemo.ClearableEditText
                    android:id="@+id/email"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:hint="@string/prompt_email"
                    android:imeOptions="flagNoExtractUi"
                    android:singleLine="true" />
            </android.support.design.widget.TextInputLayout>

            <android.support.design.widget.TextInputLayout
                android:id="@+id/password_text_input_layout"
                android:layout_width="match_parent"
                android:layout_height="wrap_content">

                <com.ming.doustec.clearableedittextdemo.ClearableEditText
                    android:id="@+id/password"
                    android:layout_width="match_parent"
                    android:layout_height="wrap_content"
                    android:fontFamily="sans-serif"
                    android:hint="@string/prompt_password"
                    android:imeActionId="@+id/login"
                    android:imeActionLabel="@string/action_sign_in_short"
                    android:imeOptions="flagNoFullscreen|actionUnspecified"
                    android:inputType="textPassword"
                    android:singleLine="true" />
            </android.support.design.widget.TextInputLayout>

            <Button
                android:id="@+id/email_sign_in_button"
                style="?android:textAppearanceSmallInverse"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_marginTop="16dp"
                android:text="@string/action_sign_in"
                android:textStyle="bold"
                 />

        </LinearLayout>
    </ScrollView>

</LinearLayout>
 

package com.ming.doustec.clearableedittextdemo;

import android.animation.Animator;
import android.animation.AnimatorListenerAdapter;
import android.app.Activity;
import android.content.res.Configuration;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.design.widget.TextInputLayout;
import android.support.v7.app.AppCompatActivity;
import android.text.TextUtils;
import android.view.KeyEvent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.inputmethod.EditorInfo;
import android.widget.Button;
import android.widget.TextView;


public class LoginActivity extends AppCompatActivity {



    /**
     * A dummy authentication store containing known user names and passwords.
     * TODO: remove after connecting to a real authentication system.
     */
    private static final String[] DUMMY_CREDENTIALS = new String[]{
            "
 
[email protected]:hello", "[email protected]:world"
    };
    /**
     * Keep track of the login task to ensure we can cancel it if requested.
     */
    private UserLoginTask mAuthTask = null;

    // UI references.
    private TextInputLayout mEmailView;
    private TextInputLayout mPasswordView;
    private View mProgressView;
    private View mLoginFormView;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_login);
        setTitle(R.string.action_sign_in_short);

        // Set up the login form.
        mEmailView = (TextInputLayout) findViewById(R.id.email_text_input_layout);

        mPasswordView = (TextInputLayout) findViewById(R.id.password_text_input_layout);

        mPasswordView.getEditText().setOnEditorActionListener(new TextView.OnEditorActionListener() {
            @Override
            public boolean onEditorAction(TextView textView, int id, KeyEvent keyEvent) {
                if (id == R.id.login || id == EditorInfo.IME_NULL) {
                    attemptLogin();
                    return true;
                }
                return false;
            }
        });

        final Button emailSignInButton = (Button) findViewById(R.id.email_sign_in_button);
        emailSignInButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                attemptLogin();
            }
        });

        mLoginFormView = findViewById(R.id.login_form);
        mProgressView = findViewById(R.id.login_progress);
    }

    @Override
    protected void onResume() {
        super.onResume();
        if (!getResources().getBoolean(R.bool.is_tablet) && getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {
            getSupportActionBar().hide();
        } else {
            getSupportActionBar().show();
        }
    }

    /**
     * Attempts to sign in or register the account specified by the login form.
     * If there are form errors (invalid email, missing fields, etc.), the
     * errors are presented and no actual login attempt is made.
     */
    public void attemptLogin() {
        if (mAuthTask != null) {
            return;
        }

        // Reset errors.
        mEmailView.setErrorEnabled(false);
        mPasswordView.setErrorEnabled(false);

        // Store values at the time of the login attempt.
        String email = mEmailView.getEditText().getText().toString();
        String password = mPasswordView.getEditText().getText().toString();

        boolean cancel = false;
        View focusView = null;

        // Check for a valid password, if the user entered one.
        if (!TextUtils.isEmpty(password) && !isPasswordValid(password)) {
            mPasswordView.setError(getString(R.string.error_invalid_password));
            focusView = mPasswordView;
            cancel = true;
        }

        // Check for a valid email address.
        if (TextUtils.isEmpty(email)) {
            mEmailView.setError(getString(R.string.error_field_required));
            focusView = mEmailView;
            cancel = true;
        } else if (!isEmailValid(email)) {
            mEmailView.setError(getString(R.string.error_invalid_email));
            focusView = mEmailView;
            cancel = true;
        }

        if (cancel) {
            // There was an error; don't attempt login and focus the first
            // form field with an error.
            focusView.requestFocus();
        } else {
            // Show a progress spinner, and kick off a background task to
            // perform the user login attempt.
            showProgress(true);
            mAuthTask = new UserLoginTask(email, password);
            mAuthTask.execute((Void) null);
        }
    }

    private boolean isEmailValid(String email) {
        //TODO: Replace this with your own logic
        return email.contains("@");
    }

    private boolean isPasswordValid(String password) {
        //TODO: Replace this with your own logic
        return password.length() > 4;
    }

    /**
     * Shows the progress UI and hides the login form.
     */
    public void showProgress(final boolean show) {
        int shortAnimTime = getResources().getInteger(android.R.integer.config_shortAnimTime);

        mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
        mLoginFormView.animate().setDuration(shortAnimTime).alpha(
                show ? 0 : 1).setListener(new AnimatorListenerAdapter() {
            @Override
            public void onAnimationEnd(Animator animation) {
                mLoginFormView.setVisibility(show ? View.GONE : View.VISIBLE);
            }
        });

        mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
        mProgressView.animate().setDuration(shortAnimTime).alpha(
                show ? 1 : 0).setListener(new AnimatorListenerAdapter() {
            @Override
            public void onAnimationEnd(Animator animation) {
                mProgressView.setVisibility(show ? View.VISIBLE : View.GONE);
            }
        });
    }

    /**
     * Represents an asynchronous login/registration task used to authenticate
     * the user.
     */
    public class UserLoginTask extends AsyncTask<Void, Void, Boolean> {

        private final String mEmail;
        private final String mPassword;

        UserLoginTask(String email, String password) {
            mEmail = email;
            mPassword = password;
        }

        @Override
        protected Boolean doInBackground(Void... params) {
            // TODO: attempt authentication against a network service.

            try {
                // Simulate network access.
                Thread.sleep(2000);
            } catch (InterruptedException e) {
                return false;
            }

            for (String credential : DUMMY_CREDENTIALS) {
                String[] pieces = credential.split(":");
                if (pieces[0].equals(mEmail)) {
                    // Account exists, return true if the password matches.
                    return pieces[1].equals(mPassword);
                }
            }

            // TODO: register the new account here.
            return true;
        }

        @Override
        protected void onPostExecute(final Boolean success) {
            mAuthTask = null;
            showProgress(false);

            if (success) {
                finish();
            } else {
                mPasswordView.setError(getString(R.string.error_incorrect_password));
                mPasswordView.requestFocus();
            }
        }

        @Override
        protected void onCancelled() {
            mAuthTask = null;
            showProgress(false);
        }
    }
}