我正在使用 float 操作按钮，单击时其图像会发生变化。我有一个标志，并将其存储在共享首选项中。当为 true 时图标变为 like.png，当为 false 时图标变为 dislike.png。
我想根据标志变量更改其图标，但当应用程序启动时，其图标是默认的 true.png
如何通过共享首选项设置图标？
public class ReadActivity extends AppCompatActivity {
private FloatingActionButton fab;
private boolean flag;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_read);
fab = (FloatingActionButton) findViewById(R.id.fab);
getRate(getWindow().getDecorView().getRootView());
if(flag==false){
fab.setImageResource(R.drawable.like);
}
else if(flag==true){
fab.setImageResource(R.drawable.dislike);
}
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
getRate(v);
if(flag==false) {
rateUp();
Snackbar.make(v, "Vote +1", Snackbar.LENGTH_LONG).show();
saveRate(v, true);
fab.setImageResource(R.drawable.dislike);
}
else if(flag==true){
rateDown();
Snackbar.make(v, "Vote -1", Snackbar.LENGTH_LONG).show();
saveRate(v, false);
fab.setImageResource(R.drawable.like);
}
}
});
}
public void rateUp() {};
public void rateDown() {};
public void saveRate(View view, boolean flag){
SharedPreferences sharedPreferences = getSharedPreferences("Rates", MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putBoolean(id, flag);
editor.commit();
}
public void getRate(View view){
SharedPreferences sharedPreferences = getSharedPreferences("Rates", MODE_PRIVATE);
flag = sharedPreferences.getBoolean(id, false);
}
}
最佳答案
试试这个代码:
public class ReadActivity extends AppCompatActivity {
private FloatingActionButton fab;
private string getSharedPreferencesId="getSharedPreferencesId";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_read);
fab = (FloatingActionButton) findViewById(R.id.fab);
boolean flag=getRate();
if(flag==false){
fab.setImageResource(R.drawable.like);
}
else if(flag==true){
fab.setImageResource(R.drawable.dislike);
}
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
boolean flag=getRate();
if(flag==false) {
rateUp();
Snackbar.make(v, "Vote +1", Snackbar.LENGTH_LONG).show();
saveRate(true);
fab.setImageResource(R.drawable.dislike);
}
else if(flag==true){
rateDown();
Snackbar.make(v, "Vote -1", Snackbar.LENGTH_LONG).show();
saveRate(false);
fab.setImageResource(R.drawable.like);
}
}
});
}
public void rateUp() {};
public void rateDown() {};
public void saveRate(boolean flag){
SharedPreferences sharedPreferences = getSharedPreferences("Rates", MODE_PRIVATE);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putBoolean(getSharedPreferencesId, flag);
editor.commit();
}
public boolean getRate(){
SharedPreferences sharedPreferences = getSharedPreferences("Rates", MODE_PRIVATE);
flag = sharedPreferences.getBoolean(getSharedPreferencesId, false);
}
}
关于java - 更改 float 操作按钮背景，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/40571621/