02-06Android学习进度报告六

    今天学习了关于Android开发中常用的两个知识，即对话框和悬浮框。

首先我学习了对话框的基本使用流程

• Step 1：创建AlertDialog.Builder对象；
• Step 2：调用setIcon()设置图标，setTitle()或setCustomTitle()设置标题；
• Step 3：设置对话框的内容：setMessage()还有其他方法来指定显示的内容；
• Step 4：调用setPositive/Negative/NeutralButton()设置：确定，取消，中立按钮；
• Step 5：调用create()方法创建这个对象，再调用show()方法将对话框显示出来；

实例代码如下：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

    private Button btn_dialog_one;
    private Button btn_dialog_two;
    private Button btn_dialog_three;
    private Button btn_dialog_four;

    private Context mContext;
    private boolean[] checkItems;

    private AlertDialog alert = null;
    private AlertDialog.Builder builder = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mContext = MainActivity.this;
        bindView();


    }

    private void bindView() {
        btn_dialog_one = (Button) findViewById(R.id.btn_dialog_one);
        btn_dialog_two = (Button) findViewById(R.id.btn_dialog_two);
        btn_dialog_three = (Button) findViewById(R.id.btn_dialog_three);
        btn_dialog_four = (Button) findViewById(R.id.btn_dialog_four);
        btn_dialog_one.setOnClickListener(this);
        btn_dialog_two.setOnClickListener(this);
        btn_dialog_three.setOnClickListener(this);
        btn_dialog_four.setOnClickListener(this);
    }


    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            //普通对话框
            case R.id.btn_dialog_one:
                alert = null;
                builder = new AlertDialog.Builder(mContext);
                alert = builder.setIcon(R.mipmap.ic_icon_fish)
                        .setTitle("系统提示：")
                        .setMessage("这是一个最普通的AlertDialog,
带有三个按钮，分别是取消，中立和确定")
                        .setNegativeButton("取消", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                Toast.makeText(mContext, "你点击了取消按钮~", Toast.LENGTH_SHORT).show();
                            }
                        })
                        .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                Toast.makeText(mContext, "你点击了确定按钮~", Toast.LENGTH_SHORT).show();
                            }
                        })
                        .setNeutralButton("中立", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                Toast.makeText(mContext, "你点击了中立按钮~", Toast.LENGTH_SHORT).show();
                            }
                        }).create();             //创建AlertDialog对象
                alert.show();                    //显示对话框
                break;
            //普通列表对话框
            case R.id.btn_dialog_two:
                final String[] lesson = new String[]{"语文", "数学", "英语", "化学", "生物", "物理", "体育"};
                alert = null;
                builder = new AlertDialog.Builder(mContext);
                alert = builder.setIcon(R.mipmap.ic_icon_fish)
                        .setTitle("选择你喜欢的课程")
                        .setItems(lesson, new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                Toast.makeText(getApplicationContext(), "你选择了" + lesson[which], Toast.LENGTH_SHORT).show();
                            }
                        }).create();
                alert.show();
                break;
            //单选列表对话框
            case R.id.btn_dialog_three:
                final String[] fruits = new String[]{"苹果", "雪梨", "香蕉", "葡萄", "西瓜"};
                alert = null;
                builder = new AlertDialog.Builder(mContext);
                alert = builder.setIcon(R.mipmap.ic_icon_fish)
                        .setTitle("选择你喜欢的水果，只能选一个哦~")
                        .setSingleChoiceItems(fruits, 0, new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                Toast.makeText(getApplicationContext(), "你选择了" + fruits[which], Toast.LENGTH_SHORT).show();
                            }
                        }).create();
                alert.show();
                break;
            //多选列表对话框
            case R.id.btn_dialog_four:
                final String[] menu = new String[]{"水煮豆腐", "萝卜牛腩", "酱油鸡", "胡椒猪肚鸡"};
                //定义一个用来记录个列表项状态的boolean数组
                checkItems = new boolean[]{false, false, false, false};
                alert = null;
                builder = new AlertDialog.Builder(mContext);
                alert = builder.setIcon(R.mipmap.ic_icon_fish)
                        .setMultiChoiceItems(menu, checkItems, new DialogInterface.OnMultiChoiceClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which, boolean isChecked) {
                                checkItems[which] = isChecked;
                            }
                        })
                        .setPositiveButton("确定", new DialogInterface.OnClickListener() {
                            @Override
                            public void onClick(DialogInterface dialog, int which) {
                                String result = "";
                                for (int i = 0; i < checkItems.length; i++) {
                                    if (checkItems[i])
                                        result += menu[i] + " ";
                                }
                                Toast.makeText(getApplicationContext(), "客官你点了:" + result, Toast.LENGTH_SHORT).show();
                            }
                        })
                        .create();
                alert.show();
                break;
        }
    }
}

悬浮框的使用的集中常见的方法如下：

• public PopupWindow (Context context)
• public PopupWindow(View contentView, int width, int height)
• public PopupWindow(View contentView)
• public PopupWindow(View contentView, int width, int height, boolean focusable)

实例代码如下：

public class MainActivity extends AppCompatActivity {

    private Button btn_show;
    private Context mContext;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mContext = MainActivity.this;
        btn_show = (Button) findViewById(R.id.btn_show);
        btn_show.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                initPopWindow(v);
            }
        });
    }


    private void initPopWindow(View v) {
        View view = LayoutInflater.from(mContext).inflate(R.layout.item_popup, null, false);
        Button btn_xixi = (Button) view.findViewById(R.id.btn_xixi);
        Button btn_hehe = (Button) view.findViewById(R.id.btn_hehe);
        //1.构造一个PopupWindow，参数依次是加载的View，宽高
        final PopupWindow popWindow = new PopupWindow(view,
                ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT, true);

        popWindow.setAnimationStyle(R.anim.anim_pop);  //设置加载动画

        //这些为了点击非PopupWindow区域，PopupWindow会消失的，如果没有下面的
        //代码的话，你会发现，当你把PopupWindow显示出来了，无论你按多少次后退键
        //PopupWindow并不会关闭，而且退不出程序，加上下述代码可以解决这个问题
        popWindow.setTouchable(true);
        popWindow.setTouchInterceptor(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                return false;
                // 这里如果返回true的话，touch事件将被拦截
                // 拦截后 PopupWindow的onTouchEvent不被调用，这样点击外部区域无法dismiss
            }
        });
        popWindow.setBackgroundDrawable(new ColorDrawable(0x00000000));    //要为popWindow设置一个背景才有效


        //设置popupWindow显示的位置，参数依次是参照View，x轴的偏移量，y轴的偏移量
        popWindow.showAsDropDown(v, 50, 0);

        //设置popupWindow里的按钮的事件
        btn_xixi.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(MainActivity.this, "你点击了嘻嘻~", Toast.LENGTH_SHORT).show();
            }
        });
        btn_hehe.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Toast.makeText(MainActivity.this, "你点击了呵呵~", Toast.LENGTH_SHORT).show();
                popWindow.dismiss();
            }
        });
    }
}

这就是今日学习的知识与内容。