First you must activate View - All
By default the block mode merge is active. In this mode you can only use for example the toolbar icons Go to Next Difference
and Go to Previous Difference
and merge the current block with Merge First to Second
, Merge Second to First
If you want to select individual lines in different blocks for merging, you have to enable the Line Mode Merge
in menu Merge
or with the toolbar symbol left the "Save Merge Changes" (disk) symbol.
Now you can select the lines by clicking with the left mouse button at a line and using Shift and Ctrl like when selecting files in Windows Explorer to select a range of lines (Shift) or select/unselect individual lines (Ctrl).
After you have selected the lines in first OR second file, select with a single left mouse button click the line in the other file (side), where the selected lines should be inserted before of after this line.
So with this method you can for example select in file 1 (left side) the lines 8-20, 25 and 30 and insert these lines in file 2 (right side) before or after for example line 50.
You cannot replace a line in the other file with the selected lines. Simply select after inserting the lines you don't need anymore and press the key DEL to delete the selected lines.
See also the power tips Editing files in UltraCompare
and Block and line mode merge