每日日报2021.3.18

今天完成内容：

1.学习android AlertDialog

• 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;
• 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,newDialogInterface.OnClickListener(){@Overridepublicvoid 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:finalString[] fruits =newString[]{"苹果","雪梨","香蕉","葡萄","西瓜"};
                  alert =null;
                  builder =newAlertDialog.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,newDialogInterface.OnClickListener(){@Overridepublicvoid 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:finalString[] menu =newString[]{"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 =newboolean[]{false,false,false,false};
                  alert =null;
                  builder =newAlertDialog.Builder(mContext);
                  alert = builder.setIcon(R.mipmap.ic_icon_fish).setMultiChoiceItems(menu, checkItems,newDialogInterface.OnMultiChoiceClickListener(){@Overridepublicvoid onClick(DialogInterface dialog,int which,boolean isChecked){
                                  checkItems[which]= isChecked;}}).setPositiveButton("确定",newDialogInterface.OnClickListener(){@Overridepublicvoid 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;}}}

2.看视频

遇到问题：

无

明日目标：

学习Android studio的开发