如何查找以编程方式创建的TextView并在同类中调用其相关方法？

Hey there! Let's break down how to solve your two questions using your existing code as a starting point.

You've got two solid approaches to locate those dynamically made TextViews:

Using findViewById() #

Since you're setting a unique ID for each TextView with textView.setId(i) (from 1 to 5), you can directly use findViewById() to grab any specific one. Just pass the ID you assigned:

// For API level < 26, you'll need to cast the result
TextView targetTextView = (TextView) findViewById(3); // Gets the 3rd TextView you created

// For API 26+, casting isn't required
TextView targetTextView = findViewById(3);

⚠️ A quick note: Using hardcoded integers like 1, 2 etc. might risk ID conflicts with system views or other elements in your layout. A safer alternative is to generate a unique ID using View.generateViewId():

textView.setId(View.generateViewId());

If you go this route, store these generated IDs (like in a list) so you can reference them later.

Storing TextViews in a Collection (Recommended) #

A more reliable method—especially if you plan to work with all the TextViews later—is to save them in a list as you create them. First, add a member variable to your MainActivity:

private List<TextView> textViewList = new ArrayList<>();

Then update your CreateDesign() method to add each new TextView to the list:

public void CreateDesign(){ 
    linearLayout = findViewById(R.id.linearLayout); // No need to cast in API 26+
    for(int i = 1; i <= 5; i++){ 
        TextView textView = new TextView(this); // Use a local variable instead of the member one
        textView.setId(i); 
        textView.setText(i + ". TextView"); 
        linearLayout.addView(textView);
        textViewList.add(textView); // Add to the list
    } 
}

Now you can easily access any TextView by index:

TextView firstTextView = textViewList.get(0); // Gets the first TextView you created

Once you've located the TextViews, calling methods like setText() or setBackgroundColor() is straightforward:

If you used findViewById() #

Just make sure the TextView isn't null before calling methods (to avoid crashes):

TextView targetTv = findViewById(2);
if(targetTv != null) {
    targetTv.setText("Updated Text for 2nd TextView");
    targetTv.setBackgroundColor(Color.BLUE);
}

If you used a Collection #

You can either update a specific TextView by index or loop through all of them:

// Update a single TextView
textViewList.get(4).setText("Last TextView Updated!");
textViewList.get(4).setBackgroundColor(Color.GREEN);

// Update all TextViews
for(TextView tv : textViewList) {
    tv.setText("All TextViews Updated");
    tv.setBackgroundColor(Color.LIGHT_GRAY);
}

Also, a quick fix for your existing code: Your current member variable private TextView textView; gets overwritten in each loop iteration, so it only holds the last TextView you created. Using a list as we did above lets you keep track of all of them.

内容的提问来源于stack exchange，提问作者FatalError