Material Design之Snackbar

java.lang.Object
↳ android.support.design.widget.Snackbar

类似于Toast,Snackbar提供一个轻量级的操作反馈。在手机底部显示一个简短的信息。经过一段时间自动消失。
可以通过setAction(CharSequence, android.view.View.OnClickListener)操作Snackbar。

Snackbar的源码还比较简单，有兴趣可以去看下。

Snackbar mySnackbar = Snackbar.make(findViewById(R.id.myCoordinatorLayout),
                                R.string.email_archived, Snackbar.LENGTH_SHORT);
mySnackbar.setAction(R.string.undo_string, new MyUndoListener());
mySnackbar.show();

public class MyUndoListener implements View.OnClickListener{

    &Override
    public void onClick(View v) {

        // Code to undo the user's last action
    }
}

注意:

setDuration既可以是LENGTH_SHORT，也可以是LENGTH_LONG,还可以自定义毫秒数。

    /** * Update the text in this {@link Snackbar}. * * @param resId The new text for the Toast. */
    @NonNull
    public Snackbar setText(@StringRes int resId) {
        return setText(mContext.getText(resId));
    }

    /** * Set how long to show the view for. * * @param duration either be one of the predefined lengths: * {@link #LENGTH_SHORT}, {@link #LENGTH_LONG}, or a custom duration * in milliseconds. */
    @NonNull
    public Snackbar setDuration(@Duration int duration) {
        mDuration = duration;
        return this;
    }

Snackbar的布局:

<?xml version="1.0" encoding="utf-8"?>
<!-- ~ Copyright (C) 2015 The Android Open Source Project ~ ~ Licensed under the Apache License, Version 2.0 (the "License"); ~ you may not use this file except in compliance with the License. ~ You may obtain a copy of the License at ~ ~ http://www.apache.org/licenses/LICENSE-2.0 ~ ~ Unless required by applicable law or agreed to in writing, software ~ distributed under the License is distributed on an "AS IS" BASIS, ~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. ~ See the License for the specific language governing permissions and ~ limitations under the License. -->
<merge xmlns:android="http://schemas.android.com/apk/res/android">
    <TextView  android:id="@+id/snackbar_text" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_weight="1" android:paddingTop="@dimen/design_snackbar_padding_vertical" android:paddingBottom="@dimen/design_snackbar_padding_vertical" android:paddingLeft="@dimen/design_snackbar_padding_horizontal" android:paddingRight="@dimen/design_snackbar_padding_horizontal" android:textAppearance="@style/TextAppearance.Design.Snackbar.Message" android:maxLines="@integer/design_snackbar_text_max_lines" android:layout_gravity="center_vertical|left|start" android:ellipsize="end"/>
    <Button  android:id="@+id/snackbar_action" android:layout_width="wrap_content" android:layout_height="wrap_content" android:layout_marginLeft="@dimen/design_snackbar_extra_spacing_horizontal" android:layout_marginStart="@dimen/design_snackbar_extra_spacing_horizontal" android:layout_gravity="center_vertical|right|end" android:paddingTop="@dimen/design_snackbar_padding_vertical" android:paddingBottom="@dimen/design_snackbar_padding_vertical" android:paddingLeft="@dimen/design_snackbar_padding_horizontal" android:paddingRight="@dimen/design_snackbar_padding_horizontal" android:visibility="gone" android:textColor="?attr/colorAccent" style="?attr/borderlessButtonStyle"/>
</merge>

在API中提供了setActionTextColor 方法设置按钮的颜色，如果想设置文本提示的颜色呢？API没提供，但是我们知道Snackbar的布局文件，我们可以通过snackbar.getView()找到那个Snackbar的布局。

FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
        fab.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Snackbar snackbar = Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_INDEFINITE)
                        .setAction("Action", new View.OnClickListener() {
                            @Override
                            public void onClick(View v) {

                            }
                        }).setActionTextColor(Color.WHITE).setCallback(new Snackbar.Callback() {

                            @Override
                            public void onDismissed(Snackbar snackbar, int event) {
                                super.onDismissed(snackbar, event);
                                Log.d(TAG, "onDismissed");
                            }

                            @Override
                            public void onShown(Snackbar snackbar) {
                                super.onShown(snackbar);
                                Log.d(TAG, "onShown");
                            }
                        }).setText("haha");
                View snackBarView = snackbar.getView();
                ((TextView) snackBarView.findViewById(R.id.snackbar_text)).setTextColor(Color.BLUE);
                snackbar.show();
            }
        });