popupwindow的学习

源地址：http://blog.csdn.net/xyz_lmn/article/details/6906286

自定义的一个弹窗，学习学习。

MainActivity.java:

package com.example.li.popupwindow;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.PopupWindow;

public class MainActivity extends AppCompatActivity implements View.OnClickListener{

    View view;
    PopupWindow pop;
    Button btnShowAsDrawDown;
    Button btnShowAsDrawDown1;
    Button btnShowAtLocation;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.popup_activity);
        btnShowAsDrawDown = (Button) findViewById(R.id.btnShowAsDrawDown);
        btnShowAsDrawDown.setOnClickListener(this);
        btnShowAsDrawDown1 = (Button) findViewById(R.id.btnShowAsDrawDown1);
        btnShowAsDrawDown1.setOnClickListener(this);
        btnShowAtLocation = (Button) findViewById(R.id.btnShowAt);
        btnShowAtLocation.setOnClickListener(this);
        initPopupWindow();
    }

    private void initPopupWindow() {
        view = this.getLayoutInflater().inflate(R.layout.popup_window, null);
        pop = new PopupWindow(view, ViewGroup.LayoutParams.MATCH_PARENT,
                ViewGroup.LayoutParams.WRAP_CONTENT
                );
        pop.setOutsideTouchable(true);
        Button btnpop = (Button) view.findViewById(R.id.btn_pop);
        btnpop.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                pop.dismiss();
            }
        });
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.btnShowAsDrawDown:
                if(pop.isShowing()){
                    pop.dismiss();
                }else{
                    pop.showAsDropDown(v);
                }
                break;
            case R.id.btnShowAsDrawDown1:
                if(pop.isShowing()){
                    pop.dismiss();
                }else{
                    pop.showAsDropDown(v, 0, -160);
                }
                break;
            default:
                if(pop.isShowing()){
                    pop.dismiss();
                }else{
                    pop.showAtLocation(findViewById(R.id.main),
                            Gravity.CENTER_HORIZONTAL, 0, 0
                            );
                }
                break;
        }
    }
}

popup_activity.xml:

popup_window.xml: