Android开发——简易备忘录（三）

实验内容

1. android 开发环境搭建， 开发工具可以是eclipse+adt 或android studio。

2. 按照实验课要求制作对应的app小程序，实现按钮添加备忘，并且包含日期时间。

3. 编写并提交实验报告。

实验步骤

1.部分代码如下：

部分代码如下：

2、在MainActivity中显示布局及设定按钮功能

部分代码：

public class MainActivity extends AppCompatActivity {
    public String makeTimeString(int year,int month,int day,int hour,int minute,String memoText) {
        return  year + "年" + (month + 1) + "月" + day + "日" + hour+"时" +minute+ "分------" + memoText;
    }
    public ArrayList list=new ArrayList();
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        Button b1 = (Button)findViewById(R.id.b1);
        b1.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View view) {
                startActivityForResult(new Intent(MainActivity.this,Ctime.class),1);



            }
        });

    }
    protected void onActivityResult (int requestCode, int resultCode, Intent data){
        super.onActivityResult(requestCode,resultCode,data);
        if(requestCode == 1){
            int year =data.getIntExtra("year",0);
            int month =data.getIntExtra("month",0);
            int day = data.getIntExtra("day",0);
            int hour = data.getIntExtra("hour",0);
            int minute = data.getIntExtra("minute",0);

            String memoText = data.getStringExtra("memoText");

            String text = makeTimeString(year,month,day,hour,minute,memoText);
            ArrayAdapter adapter =new ArrayAdapter(this,android.R.layout.simple_list_item_1,list);
            adapter.add(text);
            ListView listView =(ListView)findViewById(R.id.L1);
            listView.setAdapter(adapter);
        }
    }
}

3、在Ctime中获取日期时间等功能

public class Ctime extends AppCompatActivity {
    public int year;
    public int month;
    public int day;
    public int hour;
    public int minute;
    public String memoText;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_ctime);
        DatePicker dp=(DatePicker)findViewById(R.id.datePicker);
        TimePicker tp=(TimePicker)findViewById(R.id.timePicker);
        tp.setIs24HourView(true);
        Calendar c = Calendar.getInstance();

        year = c.get(Calendar.YEAR);
        month = c.get(Calendar.MONTH);
        day = c.get(Calendar.DAY_OF_MONTH);
        hour = c.get(Calendar.HOUR);
        minute = c.get(Calendar.MINUTE);

        dp.init(year, month, day, new DatePicker.OnDateChangedListener() {
            @Override
            public void onDateChanged(DatePicker datePicker, int year, int month, int day) {
                Ctime.this.year = year;
                Ctime.this.month =month;
                Ctime.this.day = day;
            }
        });
        tp.setOnTimeChangedListener(new TimePicker.OnTimeChangedListener() {
            @Override
            public void onTimeChanged(TimePicker timePicker, int hour, int minute) {
                Ctime.this.hour = hour;
                Ctime.this.minute =minute;
            }
        });

        Button b2 =(Button)findViewById(R.id.bt1);
        b2.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                EditText text=(EditText)findViewById(R.id.edt1);
                memoText =text.getText().toString();
                Intent data =new Intent();
                data.putExtra("year",year);
                data.putExtra("month",month);
                data.putExtra("day",day);
                data.putExtra("hour",hour);
                data.putExtra("minute",minute);
                data.putExtra("memoText",memoText);
                setResult(1,data);
                finish();
            }
        });

    }
   public void Onclick(View view){
       AlertDialog.Builder b = new AlertDialog.Builder(Ctime.this);
       b.setTitle("请绘制：");
       View MyView = new MyView(Ctime.this);
       b.setView(MyView);
       b.setPositiveButton("确定", new DialogInterface.OnClickListener() {
           @Override
           public void onClick(DialogInterface dialog, int which) {


           }
       });
       b.show();
    }


}

4、新建MyView.java并完成绘制图像功能

public class MyView extends View {

    float firstX;
    float firstY;

    Path path;

    MyView(Context context)
    {
        super(context);

        path = new Path();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);

        Paint paint = new Paint();

        paint.setColor(Color.BLUE);
        paint.setStrokeWidth(10);

        //让画出的图形是空心的
        paint.setStyle(Paint.Style.STROKE);
        canvas.drawPath(path,paint);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {

        int act = event.getAction();

        if (act == MotionEvent.ACTION_DOWN)
        {
            float x = event.getX();
            float y = event.getY();
            firstX = x;
            firstY = y;
            path.moveTo(firstX,firstY);
            return true;
        }
        else if (act == MotionEvent.ACTION_MOVE)
        {
            float x = event.getX();
            float y = event.getY();
            path.lineTo(x,y);

            invalidate();
        }
        return super.onTouchEvent(event);
    }
}

实验结果

当按动“添加图像”按钮按钮时，添加图像如图：