Android实现风蓝记事本（4）：增加记事功能

川长思鸟来 2022-05-24 04:15 171阅读 0赞

package com.example.notes;
    
    
    import java.text.SimpleDateFormat;
    import java.util.Date;
    
    
    
    import android.app.Activity;
    import android.app.Dialog;
    import android.content.Intent;
    import android.content.SharedPreferences;
    import android.database.Cursor;
    import android.os.Bundle;
    import android.view.Menu;
    import android.view.View;
    import android.view.View.OnClickListener;
    import android.widget.Button;
    import android.widget.EditText;
    import android.widget.ImageButton;
    import android.widget.LinearLayout;
    import android.widget.TextView;
    import android.widget.Toast;
    
    public class Add extends Activity{
    
        private LinearLayout layout;         //布局容器
        private EditText add_content;        //内容框
        private EditText add_title;          //标题框
        private ImageButton backBtn;      //返回
        private ImageButton clearBtn;     //清空
        private ImageButton saveBtn;      //保存
    
        private DatabaseManage dm = null;// 数据库管理对象
        private Cursor cursor = null;
        private int background;//背景
        private  SharedPreferences sp;//存储数据
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.add);
    
            layout=(LinearLayout)findViewById(R.id.add);
            add_content=(EditText)findViewById(R.id.add_content);
            add_title=(EditText)findViewById(R.id.add_title);
            dm = new DatabaseManage(this);
            background=R.drawable.skin_first;
            getBackground();
            //拿到主界面地方传过来的数据，并显示出来，显示say感悟和帮助信息
            if(getIntent().hasExtra("title"))
            {
                Bundle data=getIntent().getExtras();
                if(data.containsKey("title"))
                    add_title.setText(data.getString("title"));
                if(data.containsKey("content"))
                    add_content.setText(data.getString("content"));
    
            }
            saveBtn=(ImageButton)findViewById(R.id.save_btn);
            backBtn=(ImageButton)findViewById(R.id.back_btn);
            clearBtn=(ImageButton)findViewById(R.id.clear_btn);
            ImageButton[] btns={backBtn,clearBtn,saveBtn};
            for(ImageButton btn:btns)
                btn.setOnClickListener(click);
        }
    
        //设置背景
        private void getBackground() {
            sp = getSharedPreferences("backgrounds", 0);
            background = sp.getInt("background", background);
            layout.setBackgroundResource(background);
        }
    
        private OnClickListener click=new OnClickListener() {
    
            @Override
            public void onClick(View v) {
                // TODO Auto-generated method stub
                switch (v.getId()) {
                    case R.id.back_btn:
                        back();
                        break;
                    case R.id.clear_btn:
                        clear();
                        break;
                    case R.id.save_btn:
                        save();
                    default:
                        break;
                }
            }
            //清空内容
            private void clear() {
                // TODO Auto-generated method stub
                View deleteView=View.inflate(Add.this, R.layout.deletenote, null);
                final Dialog clearDialog=new Dialog(Add.this,R.style.dialog);
                clearDialog.setContentView(deleteView);
                Button yesBtn=(Button)deleteView.findViewById(R.id.delete_yes);
                Button noBtn=(Button)deleteView.findViewById(R.id.delete_no);
                yesBtn.setText(R.string.clear_note);
                noBtn.setText(R.string.clear_cancel);
                yesBtn.setOnClickListener(new OnClickListener() {
    
                    @Override
                    public void onClick(View arg0) {
                        // TODO Auto-generated method stub
                        add_title.setText("");
                        add_content.setText("");
                        clearDialog.dismiss();
                    }
                });
                noBtn.setOnClickListener(new OnClickListener() {
    
                    @Override
                    public void onClick(View arg0) {
                        // TODO Auto-generated method stub
                        clearDialog.dismiss();
                    }
                });
                clearDialog.show();
            }
            //返回主界面
            private void back() {
                // TODO Auto-generated method stub
                Intent intent=new Intent(Add.this,MainActivity.class);
                startActivity(intent);
                finish();
            }
            //增加记事记录
            private void save() {
                // TODO Auto-generated method stub
                String n_title=add_title.getText().toString().trim();
                if(n_title.length()==0)
                    n_title="无标题";
                String n_content=add_content.getText().toString().trim();
                SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                String n_time=df.format(new Date());
                if(n_content.trim().length()>0){
                    dm.open();
                    long flag=dm.insert(n_title, n_content, n_time);
                    Toast.makeText(Add.this, R.string.note_saved, Toast.LENGTH_SHORT).show();
                    Intent intent=new Intent(Add.this,MainActivity.class);
                    startActivity(intent);
                    finish();
                }
                else
                    Toast.makeText(Add.this, R.string.note_null, Toast.LENGTH_SHORT).show();
            }
        };
        @Override
        public boolean onCreateOptionsMenu(Menu menu) {
            return true;
        }
    
    }

用到的布局：setContentView(R.layout.add)--》add.xml

# 注：源码下载：[https://download.csdn.net/download/weixin\_39220472/10426057][https_download.csdn.net_download_weixin_39220472_10426057] #

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[https_download.csdn.net_download_weixin_39220472_10426057]: https://download.csdn.net/download/weixin_39220472/10426057