1.默认样式

 new AlertDialog.Builder(activity)
                .setTitle("title")
                .setMessage("message?")
                //点击边缘弹窗是否会消失
                .setCancelable(false)
                .setPositiveButton("Positive", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                    }
                })
                .setNeutralButton("Neutral", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialogInterface, int i) {
                    }
                })

                .setNegativeButton("Negative", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                    }
                })
                .show();

2.单选，不同样式

 final String[] data = new String[]{"数据1", "数据2"};
        new AlertDialog.Builder(activity)
                .setTitle("请选择")
                .setItems(gender, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {

                    }
                }).show();

        new AlertDialog.Builder(activity)
                .setTitle("请选择")
                .setSingleChoiceItems(gender, 1, new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {

                    }
                }).show();

3.多选框

String[] data = new String[]{"数据1","数据2","数据3","数据4"};
boolean[] begin = new boolean[]{false,false,false,false};
new AlertDialog.Builder(activity)
        .setTitle("请选择")
        .setMultiChoiceItems(dessert, begin, new DialogInterface.OnMultiChoiceClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which, boolean isChecked) {

            }
        })
       .setPositiveButton("确认", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {

            }
        })
        .setNegativeButton("取消", new DialogInterface.OnClickListener() {
            @Override
            public void onClick(DialogInterface dialog, int which) {

            }
        }).show();

4.自定义弹窗

AlertDialog mDialog = new AlertDialog.Builder(this).create();
View view = getLayoutInflater().inflate(R.layout.dialog, null);
Objects.requireNonNull(mDialog.getWindow()).setBackgroundDrawableResource(android.R.color.transparent);
mDialog.setView(view);
mDialog.setCancelable(true);
mDialog.show();
view.findViewById(R.id.im_btn).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                //点击事件要做的事情
                mDialog.dismiss();
            }
        });