我们使用Dialog来实现中间弹框和底部弹框两种效果

第一种：底部弹框
效果如下图：

787123ab-5fe6-4b12-95ef-6f00e8ebc609.gif

1、定义DemoDialog,继承Dialog

public class DemoDialog extends Dialog {
    DemoDialogClickCallback demoDialogClickCallback;
    Context context;
    String title;
    String content;

    public DemoDialog(@NonNull Context context, String title, String content,DemoDialogClickCallback demoDialogClickCallback) {
        super(context);
        this.context = context;
        this.content = content;
        this.title = title;
        this.demoDialogClickCallback=demoDialogClickCallback;
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.dialog_demo);
        Window window = getWindow();
        window.setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));

        //底部弹框效果
        window.setLayout(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        window.setGravity(Gravity.BOTTOM);
        window.setWindowAnimations(R.style.animate_dialog);

        //中间弹框效果
//        window.setLayout(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
//        window.setGravity(Gravity.CENTER);

        TextView titleView=findViewById(R.id.title);
        TextView contentView=findViewById(R.id.content);
        Button  buttonView=findViewById(R.id.i_know);

        buttonView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                demoDialogClickCallback.iKonw();
            }
        });

        titleView.setText(this.title);
        contentView.setText(this.content);


        setCanceledOnTouchOutside(false);
    }

    public interface DemoDialogClickCallback {
        public void iKonw();
    }

}

2、设置弹框的入场出场动画 animate_dialog

    <style name="animate_dialog">
        <item name="android:windowEnterAnimation">@anim/anim_bottom_in</item>
        <item name="android:windowExitAnimation">@anim/anim_bottom_out</item>
    </style>

3、调用方法

 demoDialog = new DemoDialog(this, "小区公告", "今天晚上在惠民广场，红星乐队惊艳演出，同志们都来参见！！", new DemoDialog.DemoDialogClickCallback() {
            @Override
            public void iKonw() {
                demoDialog.dismiss();
            }
        });
        demoDialog.show();

第二种：中间弹框
效果如下：

ab02fb39-658f-4f59-865b-21ee042dc4d4.gif

弹框位置控制的关键属性
把  
 window.setGravity(Gravity.BOTTOM);
改成
window.setGravity(Gravity.CENTER);
即可实现