代码
一、准备工作：
1、LinkedList存储已添加的控件，制成索引，可配合数据库删除数据。
private LinkedList<Button> ListBtn_Add;
private LinkedList<TextView> ListText_Def;
2、获取手机屏幕的宽高，用于设置控件的宽高。
DisplayMetrics dm = new DisplayMetrics();
dm = getResources().getDisplayMetrics();
width=dm.widthPixels;
height=dm.heightPixels;
3、用EDITSTATE判断是否可以删除控件和数据，为0时不能删除，为1时则相反
private int EDITSTATE=0
4、因为不论是跳入WeatherAddActivity还是从ChooseAreaActivity退回到该Activity，都要根据数据库里的城市数据动态添加控件，所以我把程序都挪到了onStart()中写。
图片来自网络.png
二、onStart()
1、清空LinkedList的所有数据，并删除所有动态添加的控件，再根据数据库添加控件
ListText_Def.clear();
ListBtn_Add.clear();
linearLayout.removeAllViews();
List<County_Addition> countyAdditions= DataSupport.findAll(County_Addition.class);
for(County_Addition countyAddition:countyAdditions){//动态添加数据库中所有数据
addBtn(countyAddition.getWeatherName(),countyAddition.getDef());
}
2、动态添加控件：
private void addBtn(String countyName, Boolean Def_flag){
//添加外部Layout
LinearLayout linear_btn = new LinearLayout(this);
linear_btn.setOrientation(LinearLayout.HORIZONTAL);
LinearLayout.LayoutParams liParam = new LinearLayout.LayoutParams(
ViewGroup.LayoutParams.MATCH_PARENT,
ViewGroup.LayoutParams.WRAP_CONTENT);
linear_btn.setLayoutParams(liParam);
//添加按钮
Button btnAdd=new Button(this);
LinearLayout.LayoutParams btnAddPar=new LinearLayout.LayoutParams
(ViewGroup.LayoutParams.WRAP_CONTENT, height/8,3);
btnAddPar.setMargins(0,10,5,10);
btnAdd.setLayoutParams(btnAddPar);
btnAdd.setText(countyName);
btnAdd.setTextColor(Color.argb(255, 255, 255, 255));
btnAdd.setBackgroundColor(Color.argb(136, 0, 0, 0));
btnAdd.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(EDITSTATE==1)
delBtn(view);
}
});
linear_btn.addView(btnAdd);
ListBtn_Add.add(btnAdd);
//添加TextView
TextView textDef=new TextView(this);
LinearLayout.LayoutParams textDefPar = new LinearLayout.LayoutParams
(ViewGroup.LayoutParams.WRAP_CONTENT, height/8, 1);
textDefPar.setMargins(0, 10, 0, 10);
textDef.setLayoutParams(textDefPar);
if(Def_flag==true){
textDef.setBackgroundColor(Color.argb(255, 171, 52, 56));
textDef.setText("默认");
}else if(Def_flag==false){
textDef.setText("设为默认");
textDef.setBackgroundColor(Color.argb(136, 0, 0, 0));
}
textDef.setGravity(Gravity.CENTER);
textDef.setTextColor(Color.argb(255, 255, 255, 255));
linear_btn.addView(textDef);
textDef.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
int k=0;
for(int i=0;i<ListText_Def.size();i++){
ListText_Def.get(i).setBackgroundColor(Color.argb(136, 0, 0, 0));
ListText_Def.get(i).setText("设为默认");
if(ListText_Def.get(i)==view){
view.setBackgroundColor(Color.argb(255, 171, 52, 56));
ListText_Def.get(i).setText("默认");
k=i;
}
}
County_Addition countyAddition=new County_Addition();
countyAddition.setToDefault("Def");
countyAddition.updateAll();
County_Addition countyAddition1=new County_Addition();
countyAddition1.setDef(true);
countyAddition1.updateAll("WeatherName = ?",ListBtn_Add.get(k).getText().toString());
}
});
ListText_Def.add(textDef);
linearLayout.addView(linear_btn);
}
3、动态删除控件和数据：
private void delBtn(View view){
int countyid;
Boolean flag=false;
if(view==null){
return;
}
int iIndex=-1,position=0;
for(int i=0;i<ListBtn_Add.size();i++){
if(ListBtn_Add.get(i)==view){
iIndex=i;
break;
}
}
if(iIndex>=0){
List<County_Addition> countyAdditions= DataSupport.findAll(County_Addition.class);
for(County_Addition countyAddition:countyAdditions){
if(position==iIndex){
countyid=countyAddition.getId();
Log.d("TAG",countyid+"");
if(countyAddition.getDef()==true){
flag=true;
}
DataSupport.delete(County_Addition.class,countyid);
break;
}
position++;
}
ListBtn_Add.remove(iIndex);
ListText_Def.remove(iIndex);
Log.d("TAG",!ListBtn_Add.isEmpty()+"");
if(flag&&(!ListBtn_Add.isEmpty())){
Log.d("TAG","First");
ListText_Def.get(0).setText("默认");
ListText_Def.get(0).setBackgroundColor(Color.argb(255, 171, 52, 56));
County_Addition countyAddition=new County_Addition();
countyAddition.setDef(true);
countyAddition.updateAll("WeatherName = ?",ListBtn_Add.get(0).getText().toString());
}
linearLayout.removeViewAt(iIndex);
}
}
3、点击事件：
btn_edit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
if(EDITSTATE==0){
btn_edit.setText("确定");
EDITSTATE=1;
}else if(EDITSTATE==1){
btn_edit.setText("编辑");
EDITSTATE=0;
}
}
});
btn_add.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Intent intent=new Intent(WeatherAddActivity.this,ChooseAreaActivity.class);
SharedPreferences.Editor editor= PreferenceManager.
getDefaultSharedPreferences(WeatherAddActivity.this).edit();
editor.putBoolean("Where",true);
editor.apply();
linearLayout.removeAllViews();
startActivity(intent);
}
});
btn_back.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
//判断数据库的数据是否为空
List<County_Addition> countyAdditions= DataSupport.findAll(County_Addition.class);
for(County_Addition countyAddition:countyAdditions){
number++;
}
if(number==0){
Toast.makeText(WeatherAddActivity.this,"城市不能为空，请添加城市",Toast.LENGTH_SHORT).show();
}else{
number=0;
finish();
}
}
});
NEXT：
酷欧天气2.0（四）——显示城市天气数据WeatherActivity
https://www.jianshu.com/p/62a96eab333f
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